Bump version numbers for 1.2.13 release.

Do not produce malformed links for adding contacts when on other locales such as Turkish

Closes #1885

See merge request briar/briar!1335

.idea/codeStyles/Project.xml

@@ -1,8 +1,5 @@
 <component name="ProjectCodeStyleConfiguration">
   <code_scheme name="Project" version="173">
-    <AndroidXmlCodeStyleSettings>
-      <option name="ARRANGEMENT_SETTINGS_MIGRATED_TO_191" value="true" />
-    </AndroidXmlCodeStyleSettings>
     <JavaCodeStyleSettings>
       <option name="ANNOTATION_PARAMETER_WRAP" value="1" />
       <option name="IMPORT_LAYOUT_TABLE">
@@ -31,6 +28,20 @@
       <option name="JD_ALIGN_EXCEPTION_COMMENTS" value="false" />
     </JavaCodeStyleSettings>
     <JetCodeStyleSettings>
+      <option name="PACKAGES_TO_USE_STAR_IMPORTS">
+        <value />
+      </option>
+      <option name="PACKAGES_IMPORT_LAYOUT">
+        <value>
+          <package name="" alias="false" withSubpackages="true" />
+          <package name="java" alias="false" withSubpackages="true" />
+          <package name="javax" alias="false" withSubpackages="true" />
+          <package name="kotlin" alias="false" withSubpackages="true" />
+          <package name="" alias="true" withSubpackages="true" />
+        </value>
+      </option>
+      <option name="NAME_COUNT_TO_USE_STAR_IMPORT" value="2147483647" />
+      <option name="NAME_COUNT_TO_USE_STAR_IMPORT_FOR_MEMBERS" value="2147483647" />
       <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
     </JetCodeStyleSettings>
     <XML>

.idea/runConfigurations/All_tests.xml

@@ -1,6 +1,6 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="All tests" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="briar-android" />
+    <module name="briar.briar-android" />
     <option name="PACKAGE_NAME" value="" />
     <option name="MAIN_CLASS_NAME" value="" />
     <option name="METHOD_NAME" value="" />

.idea/runConfigurations/All_tests_in_bramble_android.xml

@@ -1,20 +1,14 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="All tests in bramble-android" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="bramble-android" />
+    <module name="briar.bramble-android" />
-    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
-    <option name="ALTERNATIVE_JRE_PATH" />
     <option name="PACKAGE_NAME" value="" />
     <option name="MAIN_CLASS_NAME" value="" />
     <option name="METHOD_NAME" value="" />
     <option name="TEST_OBJECT" value="package" />
-    <option name="VM_PARAMETERS" value="-ea" />
     <option name="PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/bramble-android" />
-    <option name="PASS_PARENT_ENVS" value="true" />
+    <method v="2">
-    <option name="TEST_SEARCH_SCOPE">
+      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
-      <value defaultName="singleModule" />
+    </method>
-    </option>
-    <patterns />
-    <method />
   </configuration>
 </component>

.idea/runConfigurations/All_tests_in_bramble_api.xml

@@ -1,20 +1,14 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="All tests in bramble-api" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="bramble-api" />
+    <module name="briar.bramble-api" />
-    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
-    <option name="ALTERNATIVE_JRE_PATH" />
     <option name="PACKAGE_NAME" value="" />
     <option name="MAIN_CLASS_NAME" value="" />
     <option name="METHOD_NAME" value="" />
     <option name="TEST_OBJECT" value="package" />
-    <option name="VM_PARAMETERS" value="-ea" />
     <option name="PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/bramble-api" />
-    <option name="PASS_PARENT_ENVS" value="true" />
+    <method v="2">
-    <option name="TEST_SEARCH_SCOPE">
+      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
-      <value defaultName="singleModule" />
+    </method>
-    </option>
-    <patterns />
-    <method />
   </configuration>
 </component>

.idea/runConfigurations/All_tests_in_bramble_core.xml

@@ -1,20 +1,14 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="All tests in bramble-core" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="bramble-core" />
+    <module name="briar.bramble-core" />
-    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
-    <option name="ALTERNATIVE_JRE_PATH" />
     <option name="PACKAGE_NAME" value="" />
     <option name="MAIN_CLASS_NAME" value="" />
     <option name="METHOD_NAME" value="" />
     <option name="TEST_OBJECT" value="package" />
-    <option name="VM_PARAMETERS" value="-ea" />
     <option name="PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/bramble-core" />
-    <option name="PASS_PARENT_ENVS" value="true" />
+    <method v="2">
-    <option name="TEST_SEARCH_SCOPE">
+      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
-      <value defaultName="singleModule" />
+    </method>
-    </option>
-    <patterns />
-    <method />
   </configuration>
 </component>

.idea/runConfigurations/All_tests_in_bramble_java.xml

@@ -1,8 +1,6 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="All tests in bramble-java" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="bramble-java" />
+    <module name="briar.bramble-java" />
-    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
-    <option name="ALTERNATIVE_JRE_PATH" />
     <option name="PACKAGE_NAME" value="" />
     <option name="MAIN_CLASS_NAME" value="" />
     <option name="METHOD_NAME" value="" />
@@ -10,11 +8,8 @@
     <option name="VM_PARAMETERS" value="-ea -Djava.library.path=libs" />
     <option name="PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/bramble-java" />
-    <option name="PASS_PARENT_ENVS" value="true" />
+    <method v="2">
-    <option name="TEST_SEARCH_SCOPE">
+      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
-      <value defaultName="singleModule" />
+    </method>
-    </option>
-    <patterns />
-    <method />
   </configuration>
 </component>

.idea/runConfigurations/All_tests_in_briar_android.xml

@@ -1,20 +1,14 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="All tests in briar-android" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="briar-android" />
+    <module name="briar.briar-android" />
-    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
-    <option name="ALTERNATIVE_JRE_PATH" />
     <option name="PACKAGE_NAME" value="" />
     <option name="MAIN_CLASS_NAME" value="" />
     <option name="METHOD_NAME" value="" />
     <option name="TEST_OBJECT" value="package" />
-    <option name="VM_PARAMETERS" value="-ea" />
     <option name="PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/briar-android" />
-    <option name="PASS_PARENT_ENVS" value="true" />
+    <method v="2">
-    <option name="TEST_SEARCH_SCOPE">
+      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
-      <value defaultName="singleModule" />
+    </method>
-    </option>
-    <patterns />
-    <method />
   </configuration>
 </component>

.idea/runConfigurations/All_tests_in_briar_core.xml

@@ -1,20 +1,14 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="All tests in briar-core" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="briar-core" />
+    <module name="briar.briar-core" />
-    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
-    <option name="ALTERNATIVE_JRE_PATH" />
     <option name="PACKAGE_NAME" value="" />
     <option name="MAIN_CLASS_NAME" value="" />
     <option name="METHOD_NAME" value="" />
     <option name="TEST_OBJECT" value="package" />
-    <option name="VM_PARAMETERS" value="-ea" />
     <option name="PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/briar-core" />
-    <option name="PASS_PARENT_ENVS" value="true" />
+    <method v="2">
-    <option name="TEST_SEARCH_SCOPE">
+      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
-      <value defaultName="singleModule" />
+    </method>
-    </option>
-    <patterns />
-    <method />
   </configuration>
 </component>

.idea/runConfigurations/All_tests_in_briar_headless.xml

@@ -1,6 +1,6 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="All tests in briar-headless" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="briar-headless" />
+    <module name="briar.briar-headless" />
     <option name="PACKAGE_NAME" value="org.briarproject.briar.headless" />
     <option name="MAIN_CLASS_NAME" value="" />
     <option name="METHOD_NAME" value="" />

.idea/runConfigurations/H2_Performance_Test.xml

@@ -1,20 +1,14 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="H2 Performance Test" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="bramble-core" />
+    <module name="briar.bramble-core" />
-    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
-    <option name="ALTERNATIVE_JRE_PATH" />
     <option name="PACKAGE_NAME" value="org.briarproject.bramble.db" />
     <option name="MAIN_CLASS_NAME" value="org.briarproject.bramble.db.H2DatabasePerformanceTest" />
     <option name="METHOD_NAME" value="" />
     <option name="TEST_OBJECT" value="class" />
-    <option name="VM_PARAMETERS" value="-ea" />
     <option name="PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="" />
-    <option name="PASS_PARENT_ENVS" value="true" />
+    <method v="2">
-    <option name="TEST_SEARCH_SCOPE">
+      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
-      <value defaultName="singleModule" />
+    </method>
-    </option>
-    <patterns />
-    <method />
   </configuration>
 </component>

.idea/runConfigurations/HyperSQL_Performance_Test.xml

@@ -1,20 +1,14 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="HyperSQL Performance Test" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="bramble-core" />
+    <module name="briar.bramble-core" />
-    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
-    <option name="ALTERNATIVE_JRE_PATH" />
     <option name="PACKAGE_NAME" value="org.briarproject.bramble.db" />
     <option name="MAIN_CLASS_NAME" value="org.briarproject.bramble.db.HyperSqlDatabasePerformanceTest" />
     <option name="METHOD_NAME" value="" />
     <option name="TEST_OBJECT" value="class" />
-    <option name="VM_PARAMETERS" value="-ea" />
     <option name="PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="" />
-    <option name="PASS_PARENT_ENVS" value="true" />
+    <method v="2">
-    <option name="TEST_SEARCH_SCOPE">
+      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
-      <value defaultName="singleModule" />
+    </method>
-    </option>
-    <patterns />
-    <method />
   </configuration>
 </component>

.idea/runConfigurations/briar_headless.xml

@@ -1,6 +1,6 @@
 <component name="ProjectRunConfigurationManager">
-  <configuration default="false" name="briar-headless" type="JetRunConfigurationType" factoryName="Kotlin" singleton="true">
+  <configuration default="false" name="briar-headless" type="JetRunConfigurationType" singleton="true">
-    <extension name="coverage" enabled="false" merge="false" sample_coverage="true" runner="idea" />
+    <module name="briar.briar-headless" />
     <option name="VM_PARAMETERS" value="" />
     <option name="PROGRAM_PARAMETERS" value="-v" />
     <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
@@ -8,9 +8,8 @@
     <option name="PASS_PARENT_ENVS" value="true" />
     <option name="MAIN_CLASS_NAME" value="org.briarproject.briar.headless.MainKt" />
     <option name="WORKING_DIRECTORY" value="" />
-    <module name="briar-headless" />
+    <method v="2">
-    <envs />
+      <option name="Make" enabled="true" />
-    <method>
       <option name="Gradle.BeforeRunTask" enabled="true" tasks="jar" externalProjectPath="$PROJECT_DIR$/briar-headless" vmOptions="" scriptParameters="" />
     </method>
   </configuration>

TRANSLATION.md

@@ -0,0 +1,9 @@
+Translations for this project are managed through Transifex:
+
+https://transifex.com/otf/briar
+
+If you'd like to volunteer as a translator, please create a Transifex account and request to be
+added to the project's translation team. The Localization Lab has some instructions and advice for
+translators here:
+
+https://wiki.localizationlab.org/index.php/Briar

bramble-android/.gitignore

@@ -3,3 +3,4 @@ gen
 build
 .settings
 src/main/res/raw/*.zip
+src/main/jniLibs

bramble-android/build.gradle

@@ -5,14 +5,14 @@ apply plugin: 'witness'
 apply from: 'witness.gradle'
 
 android {
-	compileSdkVersion 29
+	compileSdkVersion rootProject.ext.compileSdkVersion
-	buildToolsVersion '29.0.2'
+	buildToolsVersion rootProject.ext.buildToolsVersion
 
 	defaultConfig {
-		minSdkVersion 16
+		minSdkVersion rootProject.ext.minSdkVersion
-		targetSdkVersion 28
+		targetSdkVersion rootProject.ext.targetSdkVersion
-		versionCode 10207
+		versionCode rootProject.ext.versionCode
-		versionName "1.2.7"
+		versionName rootProject.ext.versionName
 		consumerProguardFiles 'proguard-rules.txt'
 
 		testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
@@ -38,7 +38,7 @@ configurations {
 
 dependencies {
 	implementation project(path: ':bramble-core', configuration: 'default')
-	tor 'org.briarproject:tor-android:0.3.5.10@zip'
+	tor 'org.briarproject:tor-android:0.3.5.12@zip'
 	tor 'org.briarproject:obfs4proxy-android:0.0.11-2@zip'
 
 	annotationProcessor 'com.google.dagger:dagger-compiler:2.24'
@@ -53,10 +53,12 @@ dependencies {
 }
 
 def torBinariesDir = 'src/main/res/raw'
+def torLibsDir = 'src/main/jniLibs'
 
 task cleanTorBinaries {
 	doLast {
 		delete fileTree(torBinariesDir) { include '*.zip' }
+		delete fileTree(torLibsDir) { include '**/*.so' }
 	}
 }
 
@@ -67,8 +69,36 @@ task unpackTorBinaries {
 		copy {
 			from configurations.tor.collect { zipTree(it) }
 			into torBinariesDir
-			// TODO: Remove after next Tor upgrade, which won't include non-PIE binaries
+			include 'geoip.zip'
-			include 'geoip.zip', '*_pie.zip'
+		}
+		configurations.tor.each { outer ->
+			zipTree(outer).each { inner ->
+				if (inner.name.endsWith('_arm_pie.zip')) {
+					copy {
+						from zipTree(inner)
+						into torLibsDir
+						rename '(.*)', 'armeabi-v7a/lib$1.so'
+					}
+				} else if (inner.name.endsWith('_arm64_pie.zip')) {
+					copy {
+						from zipTree(inner)
+						into torLibsDir
+						rename '(.*)', 'arm64-v8a/lib$1.so'
+					}
+				} else if (inner.name.endsWith('_x86_pie.zip')) {
+					copy {
+						from zipTree(inner)
+						into torLibsDir
+						rename '(.*)', 'x86/lib$1.so'
+					}
+				} else if (inner.name.endsWith('_x86_64_pie.zip')) {
+					copy {
+						from zipTree(inner)
+						into torLibsDir
+						rename '(.*)', 'x86_64/lib$1.so'
+					}
+				}
+			}
 		}
 	}
 	dependsOn cleanTorBinaries
@@ -76,5 +106,6 @@ task unpackTorBinaries {
 
 tasks.withType(MergeResources) {
 	inputs.dir torBinariesDir
+	inputs.dir torLibsDir
 	dependsOn unpackTorBinaries
 }

bramble-android/src/main/AndroidManifest.xml

@@ -16,6 +16,8 @@
 		android:label="@string/app_name"
 		android:supportsRtl="true">
 
+		<receiver android:name=".system.AlarmReceiver" />
+
 	</application>
 
 </manifest>

bramble-android/src/main/java/org/briarproject/bramble/BrambleAndroidModule.java

@@ -6,6 +6,8 @@ import org.briarproject.bramble.plugin.tor.CircumventionModule;
 import org.briarproject.bramble.reporting.ReportingModule;
 import org.briarproject.bramble.socks.SocksModule;
 import org.briarproject.bramble.system.AndroidSystemModule;
+import org.briarproject.bramble.system.AndroidTaskSchedulerModule;
+import org.briarproject.bramble.system.AndroidWakefulIoExecutorModule;
 
 import dagger.Module;
 
@@ -13,6 +15,8 @@ import dagger.Module;
 		AndroidBatteryModule.class,
 		AndroidNetworkModule.class,
 		AndroidSystemModule.class,
+		AndroidTaskSchedulerModule.class,
+		AndroidWakefulIoExecutorModule.class,
 		CircumventionModule.class,
 		ReportingModule.class,
 		SocksModule.class

bramble-android/src/main/java/org/briarproject/bramble/BrambleAppComponent.java

@@ -0,0 +1,8 @@
+package org.briarproject.bramble;
+
+import org.briarproject.bramble.api.system.AlarmListener;
+
+public interface BrambleAppComponent {
+
+	AlarmListener alarmListener();
+}

bramble-android/src/main/java/org/briarproject/bramble/BrambleApplication.java

@@ -0,0 +1,6 @@
+package org.briarproject.bramble;
+
+public interface BrambleApplication {
+
+	BrambleAppComponent getBrambleAppComponent();
+}

bramble-android/src/main/java/org/briarproject/bramble/api/system/AlarmListener.java

@@ -0,0 +1,11 @@
+package org.briarproject.bramble.api.system;
+
+import android.content.Intent;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+@NotNullByDefault
+public interface AlarmListener {
+
+	void onAlarm(Intent intent);
+}

bramble-android/src/main/java/org/briarproject/bramble/api/system/AndroidWakeLock.java

@@ -0,0 +1,19 @@
+package org.briarproject.bramble.api.system;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+@NotNullByDefault
+public interface AndroidWakeLock {
+
+	/**
+	 * Acquires the wake lock. This has no effect if the wake lock has already
+	 * been acquired.
+	 */
+	void acquire();
+
+	/**
+	 * Releases the wake lock. This has no effect if the wake lock has already
+	 * been released.
+	 */
+	void release();
+}

bramble-android/src/main/java/org/briarproject/bramble/api/system/AndroidWakeLockManager.java

@@ -0,0 +1,38 @@
+package org.briarproject.bramble.api.system;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.util.concurrent.Executor;
+
+@NotNullByDefault
+public interface AndroidWakeLockManager {
+
+	/**
+	 * Creates a wake lock with the given tag. The tag is only used for
+	 * logging; the underlying OS wake lock will use its own tag.
+	 */
+	AndroidWakeLock createWakeLock(String tag);
+
+	/**
+	 * Runs the given task while holding a wake lock.
+	 */
+	void runWakefully(Runnable r, String tag);
+
+	/**
+	 * Submits the given task to the given executor while holding a wake lock.
+	 * The lock is released when the task completes, or if an exception is
+	 * thrown while submitting or running the task.
+	 */
+	void executeWakefully(Runnable r, Executor executor, String tag);
+
+	/**
+	 * Starts a dedicated thread to run the given task asynchronously. A wake
+	 * lock is acquired before starting the thread and released when the task
+	 * completes, or if an exception is thrown while starting the thread or
+	 * running the task.
+	 * <p>
+	 * This method should only be used for lifecycle management tasks that
+	 * can't be run on an executor.
+	 */
+	void executeWakefully(Runnable r, String tag);
+}

bramble-android/src/main/java/org/briarproject/bramble/network/AndroidNetworkManager.java

@@ -1,24 +1,34 @@
 package org.briarproject.bramble.network;
 
+import android.annotation.TargetApi;
 import android.app.Application;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.net.ConnectivityManager;
+import android.net.LinkAddress;
+import android.net.LinkProperties;
+import android.net.Network;
 import android.net.NetworkInfo;
 
 import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.event.EventExecutor;
 import org.briarproject.bramble.api.lifecycle.Service;
 import org.briarproject.bramble.api.network.NetworkManager;
 import org.briarproject.bramble.api.network.NetworkStatus;
 import org.briarproject.bramble.api.network.event.NetworkStatusEvent;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.system.Scheduler;
+import org.briarproject.bramble.api.system.TaskScheduler;
+import org.briarproject.bramble.api.system.TaskScheduler.Cancellable;
 
-import java.util.concurrent.Future;
+import java.net.Inet4Address;
-import java.util.concurrent.ScheduledExecutorService;
+import java.net.InetAddress;
+import java.net.NetworkInterface;
+import java.net.SocketException;
+import java.util.Enumeration;
+import java.util.concurrent.Executor;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicReference;
@@ -35,36 +45,47 @@ import static android.net.ConnectivityManager.TYPE_WIFI;
 import static android.net.wifi.p2p.WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION;
 import static android.os.Build.VERSION.SDK_INT;
 import static android.os.PowerManager.ACTION_DEVICE_IDLE_MODE_CHANGED;
+import static java.net.NetworkInterface.getNetworkInterfaces;
+import static java.util.Collections.list;
 import static java.util.concurrent.TimeUnit.MINUTES;
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static java.util.logging.Level.INFO;
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
+import static org.briarproject.bramble.util.LogUtils.logException;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 class AndroidNetworkManager implements NetworkManager, Service {
 
 	private static final Logger LOG =
-			Logger.getLogger(AndroidNetworkManager.class.getName());
+			getLogger(AndroidNetworkManager.class.getName());
 
 	// See android.net.wifi.WifiManager
 	private static final String WIFI_AP_STATE_CHANGED_ACTION =
 			"android.net.wifi.WIFI_AP_STATE_CHANGED";
 
-	private final ScheduledExecutorService scheduler;
+	private final TaskScheduler scheduler;
 	private final EventBus eventBus;
-	private final Context appContext;
+	private final Executor eventExecutor;
-	private final AtomicReference<Future<?>> connectivityCheck =
+	private final Application app;
+	private final ConnectivityManager connectivityManager;
+	private final AtomicReference<Cancellable> connectivityCheck =
 			new AtomicReference<>();
 	private final AtomicBoolean used = new AtomicBoolean(false);
 
 	private volatile BroadcastReceiver networkStateReceiver = null;
 
 	@Inject
-	AndroidNetworkManager(@Scheduler ScheduledExecutorService scheduler,
+	AndroidNetworkManager(TaskScheduler scheduler, EventBus eventBus,
-			EventBus eventBus, Application app) {
+			@EventExecutor Executor eventExecutor, Application app) {
 		this.scheduler = scheduler;
 		this.eventBus = eventBus;
-		this.appContext = app.getApplicationContext();
+		this.eventExecutor = eventExecutor;
+		this.app = app;
+		connectivityManager = (ConnectivityManager)
+				requireNonNull(app.getSystemService(CONNECTIVITY_SERVICE));
 	}
 
 	@Override
@@ -79,24 +100,82 @@ class AndroidNetworkManager implements NetworkManager, Service {
 		filter.addAction(WIFI_AP_STATE_CHANGED_ACTION);
 		filter.addAction(WIFI_P2P_THIS_DEVICE_CHANGED_ACTION);
 		if (SDK_INT >= 23) filter.addAction(ACTION_DEVICE_IDLE_MODE_CHANGED);
-		appContext.registerReceiver(networkStateReceiver, filter);
+		app.registerReceiver(networkStateReceiver, filter);
 	}
 
 	@Override
 	public void stopService() {
 		if (networkStateReceiver != null)
-			appContext.unregisterReceiver(networkStateReceiver);
+			app.unregisterReceiver(networkStateReceiver);
 	}
 
 	@Override
 	public NetworkStatus getNetworkStatus() {
-		ConnectivityManager cm = (ConnectivityManager)
+		NetworkInfo net = connectivityManager.getActiveNetworkInfo();
-				appContext.getSystemService(CONNECTIVITY_SERVICE);
-		if (cm == null) throw new AssertionError();
-		NetworkInfo net = cm.getActiveNetworkInfo();
 		boolean connected = net != null && net.isConnected();
-		boolean wifi = connected && net.getType() == TYPE_WIFI;
+		boolean wifi = false, ipv6Only = false;
-		return new NetworkStatus(connected, wifi);
+		if (connected) {
+			wifi = net.getType() == TYPE_WIFI;
+			if (SDK_INT >= 23) ipv6Only = isActiveNetworkIpv6Only();
+			else ipv6Only = areAllAvailableNetworksIpv6Only();
+		}
+		return new NetworkStatus(connected, wifi, ipv6Only);
+	}
+
+	/**
+	 * Returns true if the
+	 * {@link ConnectivityManager#getActiveNetwork() active network} has an
+	 * IPv6 unicast address and no IPv4 addresses. The active network is
+	 * assumed not to be a loopback interface.
+	 */
+	@TargetApi(23)
+	private boolean isActiveNetworkIpv6Only() {
+		Network net = connectivityManager.getActiveNetwork();
+		if (net == null) {
+			LOG.info("No active network");
+			return false;
+		}
+		LinkProperties props = connectivityManager.getLinkProperties(net);
+		if (props == null) {
+			LOG.info("No link properties for active network");
+			return false;
+		}
+		boolean hasIpv6Unicast = false;
+		for (LinkAddress linkAddress : props.getLinkAddresses()) {
+			InetAddress addr = linkAddress.getAddress();
+			if (addr instanceof Inet4Address) return false;
+			if (!addr.isMulticastAddress()) hasIpv6Unicast = true;
+		}
+		return hasIpv6Unicast;
+	}
+
+	/**
+	 * Returns true if the device has at least one network interface with an
+	 * IPv6 unicast address and no interfaces with IPv4 addresses, excluding
+	 * loopback interfaces and interfaces that are
+	 * {@link NetworkInterface#isUp() down}. If this method returns true and
+	 * the device has internet access then it's via IPv6 only.
+	 */
+	private boolean areAllAvailableNetworksIpv6Only() {
+		try {
+			Enumeration<NetworkInterface> interfaces = getNetworkInterfaces();
+			if (interfaces == null) {
+				LOG.info("No network interfaces");
+				return false;
+			}
+			boolean hasIpv6Unicast = false;
+			for (NetworkInterface i : list(interfaces)) {
+				if (i.isLoopback() || !i.isUp()) continue;
+				for (InetAddress addr : list(i.getInetAddresses())) {
+					if (addr instanceof Inet4Address) return false;
+					if (!addr.isMulticastAddress()) hasIpv6Unicast = true;
+				}
+			}
+			return hasIpv6Unicast;
+		} catch (SocketException e) {
+			logException(LOG, WARNING, e);
+			return false;
+		}
 	}
 
 	private void updateConnectionStatus() {
@@ -104,11 +183,12 @@ class AndroidNetworkManager implements NetworkManager, Service {
 	}
 
 	private void scheduleConnectionStatusUpdate(int delay, TimeUnit unit) {
-		Future<?> newConnectivityCheck =
+		Cancellable newConnectivityCheck =
-				scheduler.schedule(this::updateConnectionStatus, delay, unit);
+				scheduler.schedule(this::updateConnectionStatus, eventExecutor,
-		Future<?> oldConnectivityCheck =
+						delay, unit);
+		Cancellable oldConnectivityCheck =
 				connectivityCheck.getAndSet(newConnectivityCheck);
-		if (oldConnectivityCheck != null) oldConnectivityCheck.cancel(false);
+		if (oldConnectivityCheck != null) oldConnectivityCheck.cancel();
 	}
 
 	private class NetworkStateReceiver extends BroadcastReceiver {

bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothConnectionFactory.java

@@ -0,0 +1,36 @@
+package org.briarproject.bramble.plugin.bluetooth;
+
+import android.bluetooth.BluetoothSocket;
+
+import org.briarproject.bramble.api.io.TimeoutMonitor;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
+import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
+import org.briarproject.bramble.api.system.AndroidWakeLockManager;
+
+import java.io.IOException;
+
+@NotNullByDefault
+class AndroidBluetoothConnectionFactory
+		implements BluetoothConnectionFactory<BluetoothSocket> {
+
+	private final BluetoothConnectionLimiter connectionLimiter;
+	private final AndroidWakeLockManager wakeLockManager;
+	private final TimeoutMonitor timeoutMonitor;
+
+	AndroidBluetoothConnectionFactory(
+			BluetoothConnectionLimiter connectionLimiter,
+			AndroidWakeLockManager wakeLockManager,
+			TimeoutMonitor timeoutMonitor) {
+		this.connectionLimiter = connectionLimiter;
+		this.wakeLockManager = wakeLockManager;
+		this.timeoutMonitor = timeoutMonitor;
+	}
+
+	@Override
+	public DuplexTransportConnection wrapSocket(DuplexPlugin plugin,
+			BluetoothSocket s) throws IOException {
+		return new AndroidBluetoothTransportConnection(plugin,
+				connectionLimiter, wakeLockManager, timeoutMonitor, s);
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothPlugin.java

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.plugin.bluetooth;
 
+import android.app.Application;
 import android.bluetooth.BluetoothAdapter;
 import android.bluetooth.BluetoothDevice;
 import android.bluetooth.BluetoothServerSocket;
@@ -9,7 +10,6 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 
-import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
@@ -31,7 +31,6 @@ import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Executor;
 import java.util.concurrent.LinkedBlockingQueue;
-import java.util.concurrent.ScheduledExecutorService;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
@@ -60,35 +59,40 @@ import static org.briarproject.bramble.util.PrivacyUtils.scrubMacAddress;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
+class AndroidBluetoothPlugin
+		extends BluetoothPlugin<BluetoothSocket, BluetoothServerSocket> {
 
 	private static final Logger LOG =
 			getLogger(AndroidBluetoothPlugin.class.getName());
 
 	private static final int MAX_DISCOVERY_MS = 10_000;
 
-	private final ScheduledExecutorService scheduler;
 	private final AndroidExecutor androidExecutor;
-	private final Context appContext;
+	private final Application app;
 	private final Clock clock;
 
-	private volatile boolean wasEnabledByUs = false;
 	private volatile BluetoothStateReceiver receiver = null;
 
 	// Non-null if the plugin started successfully
 	private volatile BluetoothAdapter adapter = null;
 
 	AndroidBluetoothPlugin(BluetoothConnectionLimiter connectionLimiter,
-			TimeoutMonitor timeoutMonitor, Executor ioExecutor,
+			BluetoothConnectionFactory<BluetoothSocket> connectionFactory,
-			SecureRandom secureRandom, ScheduledExecutorService scheduler,
+			Executor ioExecutor,
-			AndroidExecutor androidExecutor, Context appContext, Clock clock,
+			Executor wakefulIoExecutor,
-			Backoff backoff, PluginCallback callback, int maxLatency,
+			SecureRandom secureRandom,
+			AndroidExecutor androidExecutor,
+			Application app,
+			Clock clock,
+			Backoff backoff,
+			PluginCallback callback,
+			int maxLatency,
 			int maxIdleTime) {
-		super(connectionLimiter, timeoutMonitor, ioExecutor, secureRandom,
+		super(connectionLimiter, connectionFactory, ioExecutor,
-				backoff, callback, maxLatency, maxIdleTime);
+				wakefulIoExecutor, secureRandom, backoff, callback,
-		this.scheduler = scheduler;
+				maxLatency, maxIdleTime);
 		this.androidExecutor = androidExecutor;
-		this.appContext = appContext;
+		this.app = app;
 		this.clock = clock;
 	}
 
@@ -100,13 +104,13 @@ class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
 		filter.addAction(ACTION_STATE_CHANGED);
 		filter.addAction(ACTION_SCAN_MODE_CHANGED);
 		receiver = new BluetoothStateReceiver();
-		appContext.registerReceiver(receiver, filter);
+		app.registerReceiver(receiver, filter);
 	}
 
 	@Override
 	public void stop() {
 		super.stop();
-		if (receiver != null) appContext.unregisterReceiver(receiver);
+		if (receiver != null) app.unregisterReceiver(receiver);
 	}
 
 	@Override
@@ -128,42 +132,11 @@ class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
 		return adapter != null && adapter.isEnabled();
 	}
 
-	@Override
-	void enableAdapter() {
-		if (adapter != null && !adapter.isEnabled()) {
-			if (adapter.enable()) {
-				LOG.info("Enabling Bluetooth");
-				wasEnabledByUs = true;
-			} else {
-				LOG.info("Could not enable Bluetooth");
-			}
-		}
-	}
-
-	@Override
-	void disableAdapterIfEnabledByUs() {
-		if (isAdapterEnabled() && wasEnabledByUs) {
-			if (adapter.disable()) LOG.info("Disabling Bluetooth");
-			else LOG.info("Could not disable Bluetooth");
-			wasEnabledByUs = false;
-		}
-	}
-
-	@Override
-	void setEnabledByUs() {
-		wasEnabledByUs = true;
-	}
-
-	@Override
-	void onAdapterDisabled() {
-		super.onAdapterDisabled();
-		wasEnabledByUs = false;
-	}
-
 	@Override
 	@Nullable
 	String getBluetoothAddress() {
-		String address = AndroidUtils.getBluetoothAddress(appContext, adapter);
+		if (adapter == null) return null;
+		String address = AndroidUtils.getBluetoothAddress(app, adapter);
 		return address.isEmpty() ? null : address;
 	}
 
@@ -181,13 +154,7 @@ class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
 	@Override
 	DuplexTransportConnection acceptConnection(BluetoothServerSocket ss)
 			throws IOException {
-		return wrapSocket(ss.accept());
+		return connectionFactory.wrapSocket(this, ss.accept());
-	}
-
-	private DuplexTransportConnection wrapSocket(BluetoothSocket s)
-			throws IOException {
-		return new AndroidBluetoothTransportConnection(this, connectionLimiter,
-				timeoutMonitor, appContext, scheduler, s);
 	}
 
 	@Override
@@ -204,7 +171,7 @@ class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
 		try {
 			s = d.createInsecureRfcommSocketToServiceRecord(u);
 			s.connect();
-			return wrapSocket(s);
+			return connectionFactory.wrapSocket(this, s);
 		} catch (IOException e) {
 			IoUtils.tryToClose(s, LOG, WARNING);
 			throw e;
@@ -239,7 +206,7 @@ class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
 		filter.addAction(ACTION_DISCOVERY_STARTED);
 		filter.addAction(ACTION_DISCOVERY_FINISHED);
 		filter.addAction(ACTION_FOUND);
-		appContext.registerReceiver(receiver, filter);
+		app.registerReceiver(receiver, filter);
 		try {
 			if (adapter.startDiscovery()) {
 				long now = clock.currentTimeMillis();
@@ -276,7 +243,7 @@ class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
 		} finally {
 			LOG.info("Cancelling discovery");
 			adapter.cancelDiscovery();
-			appContext.unregisterReceiver(receiver);
+			app.unregisterReceiver(receiver);
 		}
 		// Shuffle the addresses so we don't always try the same one first
 		shuffle(addresses);

bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothPluginFactory.java

@@ -1,9 +1,11 @@
 package org.briarproject.bramble.plugin.bluetooth;
 
-import android.content.Context;
+import android.app.Application;
+import android.bluetooth.BluetoothSocket;
 
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.io.TimeoutMonitor;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.BackoffFactory;
@@ -12,13 +14,15 @@ import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
 import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.bramble.api.system.AndroidWakeLockManager;
 import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.api.system.WakefulIoExecutor;
 
 import java.security.SecureRandom;
 import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
 
 import javax.annotation.concurrent.Immutable;
+import javax.inject.Inject;
 
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;
 
@@ -32,25 +36,32 @@ public class AndroidBluetoothPluginFactory implements DuplexPluginFactory {
 	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
 	private static final double BACKOFF_BASE = 1.2;
 
-	private final Executor ioExecutor;
+	private final Executor ioExecutor, wakefulIoExecutor;
-	private final ScheduledExecutorService scheduler;
 	private final AndroidExecutor androidExecutor;
-	private final Context appContext;
+	private final AndroidWakeLockManager wakeLockManager;
+	private final Application app;
 	private final SecureRandom secureRandom;
 	private final EventBus eventBus;
 	private final Clock clock;
 	private final TimeoutMonitor timeoutMonitor;
 	private final BackoffFactory backoffFactory;
 
-	public AndroidBluetoothPluginFactory(Executor ioExecutor,
+	@Inject
-			ScheduledExecutorService scheduler,
+	public AndroidBluetoothPluginFactory(@IoExecutor Executor ioExecutor,
-			AndroidExecutor androidExecutor, Context appContext,
+			@WakefulIoExecutor Executor wakefulIoExecutor,
-			SecureRandom secureRandom, EventBus eventBus, Clock clock,
+			AndroidExecutor androidExecutor,
-			TimeoutMonitor timeoutMonitor, BackoffFactory backoffFactory) {
+			AndroidWakeLockManager wakeLockManager,
+			Application app,
+			SecureRandom secureRandom,
+			EventBus eventBus,
+			Clock clock,
+			TimeoutMonitor timeoutMonitor,
+			BackoffFactory backoffFactory) {
 		this.ioExecutor = ioExecutor;
-		this.scheduler = scheduler;
+		this.wakefulIoExecutor = wakefulIoExecutor;
 		this.androidExecutor = androidExecutor;
-		this.appContext = appContext;
+		this.wakeLockManager = wakeLockManager;
+		this.app = app;
 		this.secureRandom = secureRandom;
 		this.eventBus = eventBus;
 		this.clock = clock;
@@ -72,12 +83,15 @@ public class AndroidBluetoothPluginFactory implements DuplexPluginFactory {
 	public DuplexPlugin createPlugin(PluginCallback callback) {
 		BluetoothConnectionLimiter connectionLimiter =
 				new BluetoothConnectionLimiterImpl(eventBus);
+		BluetoothConnectionFactory<BluetoothSocket> connectionFactory =
+				new AndroidBluetoothConnectionFactory(connectionLimiter,
+						wakeLockManager, timeoutMonitor);
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		AndroidBluetoothPlugin plugin = new AndroidBluetoothPlugin(
-				connectionLimiter, timeoutMonitor, ioExecutor, secureRandom,
+				connectionLimiter, connectionFactory, ioExecutor,
-				scheduler, androidExecutor, appContext, clock, backoff,
+				wakefulIoExecutor, secureRandom, androidExecutor, app,
-				callback, MAX_LATENCY, MAX_IDLE_TIME);
+				clock, backoff, callback, MAX_LATENCY, MAX_IDLE_TIME);
 		eventBus.addListener(plugin);
 		return plugin;
 	}

bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothTransportConnection.java

@@ -1,26 +1,19 @@
 package org.briarproject.bramble.plugin.bluetooth;
 
 import android.bluetooth.BluetoothSocket;
-import android.content.Context;
-import android.os.PowerManager;
 
 import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.duplex.AbstractDuplexTransportConnection;
-import org.briarproject.bramble.util.RenewableWakeLock;
+import org.briarproject.bramble.api.system.AndroidWakeLock;
+import org.briarproject.bramble.api.system.AndroidWakeLockManager;
 
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
-import java.util.concurrent.ScheduledExecutorService;
 
-import static android.content.Context.POWER_SERVICE;
-import static android.os.PowerManager.PARTIAL_WAKE_LOCK;
-import static java.util.concurrent.TimeUnit.MINUTES;
-import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_ADDRESS;
-import static org.briarproject.bramble.util.AndroidUtils.getWakeLockTag;
 import static org.briarproject.bramble.util.AndroidUtils.isValidBluetoothAddress;
 
 @NotNullByDefault
@@ -28,25 +21,21 @@ class AndroidBluetoothTransportConnection
 		extends AbstractDuplexTransportConnection {
 
 	private final BluetoothConnectionLimiter connectionLimiter;
-	private final RenewableWakeLock wakeLock;
 	private final BluetoothSocket socket;
 	private final InputStream in;
+	private final AndroidWakeLock wakeLock;
 
 	AndroidBluetoothTransportConnection(Plugin plugin,
 			BluetoothConnectionLimiter connectionLimiter,
-			TimeoutMonitor timeoutMonitor, Context appContext,
+			AndroidWakeLockManager wakeLockManager,
-			ScheduledExecutorService scheduler, BluetoothSocket socket)
+			TimeoutMonitor timeoutMonitor,
-			throws IOException {
+			BluetoothSocket socket) throws IOException {
 		super(plugin);
 		this.connectionLimiter = connectionLimiter;
 		this.socket = socket;
 		in = timeoutMonitor.createTimeoutInputStream(
 				socket.getInputStream(), plugin.getMaxIdleTime() * 2);
-		PowerManager powerManager = (PowerManager)
+		wakeLock = wakeLockManager.createWakeLock("BluetoothConnection");
-				requireNonNull(appContext.getSystemService(POWER_SERVICE));
-		String tag = getWakeLockTag(appContext);
-		wakeLock = new RenewableWakeLock(powerManager, scheduler,
-				PARTIAL_WAKE_LOCK, tag, 1, MINUTES);
 		wakeLock.acquire();
 		String address = socket.getRemoteDevice().getAddress();
 		if (isValidBluetoothAddress(address)) remote.put(PROP_ADDRESS, address);
@@ -66,6 +55,7 @@ class AndroidBluetoothTransportConnection
 	protected void closeConnection(boolean exception) throws IOException {
 		try {
 			socket.close();
+			in.close();
 		} finally {
 			wakeLock.release();
 			connectionLimiter.connectionClosed(this);

bramble-android/src/main/java/org/briarproject/bramble/plugin/tcp/AndroidLanTcpPlugin.java

@@ -1,7 +1,7 @@
 package org.briarproject.bramble.plugin.tcp;
 
 import android.annotation.TargetApi;
-import android.content.Context;
+import android.app.Application;
 import android.net.ConnectivityManager;
 import android.net.LinkAddress;
 import android.net.LinkProperties;
@@ -42,6 +42,7 @@ import static java.util.Collections.list;
 import static java.util.Collections.singletonList;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
 import static org.briarproject.bramble.api.plugin.LanTcpConstants.DEFAULT_PREF_PLUGIN_ENABLE;
 import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
 import static org.briarproject.bramble.api.plugin.Plugin.State.INACTIVE;
@@ -61,20 +62,22 @@ class AndroidLanTcpPlugin extends LanTcpPlugin {
 
 	private volatile SocketFactory socketFactory;
 
-	AndroidLanTcpPlugin(Executor ioExecutor, Context appContext,
+	AndroidLanTcpPlugin(Executor ioExecutor,
-			Backoff backoff, PluginCallback callback, int maxLatency,
+			Executor wakefulIoExecutor,
-			int maxIdleTime, int connectionTimeout) {
+			Application app,
-		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime,
+			Backoff backoff,
-				connectionTimeout);
+			PluginCallback callback,
+			int maxLatency,
+			int maxIdleTime,
+			int connectionTimeout) {
+		super(ioExecutor, wakefulIoExecutor, backoff, callback, maxLatency,
+				maxIdleTime, connectionTimeout);
 		// Don't execute more than one connection status check at a time
 		connectionStatusExecutor =
 				new PoliteExecutor("AndroidLanTcpPlugin", ioExecutor, 1);
-		ConnectivityManager connectivityManager = (ConnectivityManager)
+		connectivityManager = (ConnectivityManager)
-				appContext.getSystemService(CONNECTIVITY_SERVICE);
+				requireNonNull(app.getSystemService(CONNECTIVITY_SERVICE));
-		if (connectivityManager == null) throw new AssertionError();
+		wifiManager = (WifiManager) app.getSystemService(WIFI_SERVICE);
-		this.connectivityManager = connectivityManager;
-		wifiManager = (WifiManager) appContext.getApplicationContext()
-				.getSystemService(WIFI_SERVICE);
 		socketFactory = SocketFactory.getDefault();
 	}
 
@@ -274,11 +277,11 @@ class AndroidLanTcpPlugin extends LanTcpPlugin {
 				// make outgoing connections on API 21+ if another network
 				// has internet access
 				socketFactory = SocketFactory.getDefault();
-				if (s == INACTIVE) bind();
+				bind();
 			} else {
 				LOG.info("Connected to wifi");
 				socketFactory = getSocketFactory();
-				if (s == INACTIVE) bind();
+				bind();
 			}
 		});
 	}

bramble-android/src/main/java/org/briarproject/bramble/plugin/tcp/AndroidLanTcpPluginFactory.java

@@ -1,8 +1,9 @@
 package org.briarproject.bramble.plugin.tcp;
 
-import android.content.Context;
+import android.app.Application;
 
 import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.BackoffFactory;
@@ -10,10 +11,12 @@ import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
+import org.briarproject.bramble.api.system.WakefulIoExecutor;
 
 import java.util.concurrent.Executor;
 
 import javax.annotation.concurrent.Immutable;
+import javax.inject.Inject;
 
 import static org.briarproject.bramble.api.plugin.LanTcpConstants.ID;
 
@@ -28,17 +31,22 @@ public class AndroidLanTcpPluginFactory implements DuplexPluginFactory {
 	private static final int MAX_POLLING_INTERVAL = 600_000; // 10 mins
 	private static final double BACKOFF_BASE = 1.2;
 
-	private final Executor ioExecutor;
+	private final Executor ioExecutor, wakefulIoExecutor;
 	private final EventBus eventBus;
 	private final BackoffFactory backoffFactory;
-	private final Context appContext;
+	private final Application app;
 
-	public AndroidLanTcpPluginFactory(Executor ioExecutor, EventBus eventBus,
+	@Inject
-			BackoffFactory backoffFactory, Context appContext) {
+	public AndroidLanTcpPluginFactory(@IoExecutor Executor ioExecutor,
+			@WakefulIoExecutor Executor wakefulIoExecutor,
+			EventBus eventBus,
+			BackoffFactory backoffFactory,
+			Application app) {
 		this.ioExecutor = ioExecutor;
+		this.wakefulIoExecutor = wakefulIoExecutor;
 		this.eventBus = eventBus;
 		this.backoffFactory = backoffFactory;
-		this.appContext = appContext;
+		this.app = app;
 	}
 
 	@Override
@@ -56,8 +64,8 @@ public class AndroidLanTcpPluginFactory implements DuplexPluginFactory {
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		AndroidLanTcpPlugin plugin = new AndroidLanTcpPlugin(ioExecutor,
-				appContext, backoff, callback, MAX_LATENCY, MAX_IDLE_TIME,
+				wakefulIoExecutor, app, backoff, callback,
-				CONNECTION_TIMEOUT);
+				MAX_LATENCY, MAX_IDLE_TIME, CONNECTION_TIMEOUT);
 		eventBus.addListener(plugin);
 		return plugin;
 	}

bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/AndroidTorPlugin.java

@@ -1,10 +1,9 @@
 package org.briarproject.bramble.plugin.tor;
 
-import android.content.Context;
+import android.app.Application;
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.content.pm.PackageManager.NameNotFoundException;
-import android.os.PowerManager;
 
 import org.briarproject.bramble.api.battery.BatteryManager;
 import org.briarproject.bramble.api.network.NetworkManager;
@@ -12,49 +11,76 @@ import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.PluginCallback;
+import org.briarproject.bramble.api.system.AndroidWakeLock;
+import org.briarproject.bramble.api.system.AndroidWakeLockManager;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.api.system.ResourceProvider;
-import org.briarproject.bramble.util.RenewableWakeLock;
+import org.briarproject.bramble.util.AndroidUtils;
 
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
+import java.util.logging.Logger;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
 
 import javax.net.SocketFactory;
 
-import static android.content.Context.MODE_PRIVATE;
+import static android.os.Build.VERSION.SDK_INT;
-import static android.content.Context.POWER_SERVICE;
+import static java.util.Arrays.asList;
-import static android.os.PowerManager.PARTIAL_WAKE_LOCK;
+import static java.util.logging.Level.INFO;
-import static java.util.concurrent.TimeUnit.MINUTES;
+import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.util.AndroidUtils.getWakeLockTag;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 class AndroidTorPlugin extends TorPlugin {
 
-	private final Context appContext;
+	private static final List<String> LIBRARY_ARCHITECTURES =
-	private final RenewableWakeLock wakeLock;
+			asList("armeabi-v7a", "arm64-v8a", "x86", "x86_64");
 
-	AndroidTorPlugin(Executor ioExecutor, ScheduledExecutorService scheduler,
+	private static final String TOR_LIB_NAME = "libtor.so";
-			Context appContext, NetworkManager networkManager,
+	private static final String OBFS4_LIB_NAME = "libobfs4proxy.so";
-			LocationUtils locationUtils, SocketFactory torSocketFactory,
+
-			Clock clock, ResourceProvider resourceProvider,
+	private static final Logger LOG =
+			getLogger(AndroidTorPlugin.class.getName());
+
+	private final Application app;
+	private final AndroidWakeLock wakeLock;
+	private final File torLib, obfs4Lib;
+
+	AndroidTorPlugin(Executor ioExecutor,
+			Executor wakefulIoExecutor,
+			Application app,
+			NetworkManager networkManager,
+			LocationUtils locationUtils,
+			SocketFactory torSocketFactory,
+			Clock clock,
+			ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
-			BatteryManager batteryManager, Backoff backoff,
+			BatteryManager batteryManager,
+			AndroidWakeLockManager wakeLockManager,
+			Backoff backoff,
 			TorRendezvousCrypto torRendezvousCrypto,
-			PluginCallback callback, String architecture, int maxLatency,
+			PluginCallback callback,
-			int maxIdleTime) {
+			String architecture,
-		super(ioExecutor, networkManager, locationUtils, torSocketFactory,
+			int maxLatency,
-				clock, resourceProvider, circumventionProvider, batteryManager,
+			int maxIdleTime,
-				backoff, torRendezvousCrypto, callback, architecture, maxLatency, maxIdleTime,
+			File torDirectory) {
-				appContext.getDir("tor", MODE_PRIVATE));
+		super(ioExecutor, wakefulIoExecutor, networkManager, locationUtils,
-		this.appContext = appContext;
+				torSocketFactory, clock, resourceProvider,
-		PowerManager pm = (PowerManager)
+				circumventionProvider, batteryManager, backoff,
-				appContext.getSystemService(POWER_SERVICE);
+				torRendezvousCrypto, callback, architecture, maxLatency,
-		if (pm == null) throw new AssertionError();
+				maxIdleTime, torDirectory);
-		wakeLock = new RenewableWakeLock(pm, scheduler, PARTIAL_WAKE_LOCK,
+		this.app = app;
-				getWakeLockTag(appContext), 1, MINUTES);
+		wakeLock = wakeLockManager.createWakeLock("TorPlugin");
+		String nativeLibDir = app.getApplicationInfo().nativeLibraryDir;
+		torLib = new File(nativeLibDir, TOR_LIB_NAME);
+		obfs4Lib = new File(nativeLibDir, OBFS4_LIB_NAME);
 	}
 
 	@Override
@@ -65,8 +91,8 @@ class AndroidTorPlugin extends TorPlugin {
 	@Override
 	protected long getLastUpdateTime() {
 		try {
-			PackageManager pm = appContext.getPackageManager();
+			PackageManager pm = app.getPackageManager();
-			PackageInfo pi = pm.getPackageInfo(appContext.getPackageName(), 0);
+			PackageInfo pi = pm.getPackageInfo(app.getPackageName(), 0);
 			return pi.lastUpdateTime;
 		} catch (NameNotFoundException e) {
 			throw new AssertionError(e);
@@ -85,4 +111,112 @@ class AndroidTorPlugin extends TorPlugin {
 		super.stop();
 		wakeLock.release();
 	}
+
+	@Override
+	protected File getTorExecutableFile() {
+		return torLib.exists() ? torLib : super.getTorExecutableFile();
+	}
+
+	@Override
+	protected File getObfs4ExecutableFile() {
+		return obfs4Lib.exists() ? obfs4Lib : super.getObfs4ExecutableFile();
+	}
+
+	@Override
+	protected void installTorExecutable() throws IOException {
+		File extracted = super.getTorExecutableFile();
+		if (torLib.exists()) {
+			// If an older version left behind a Tor binary, delete it
+			if (extracted.exists()) {
+				if (extracted.delete()) LOG.info("Deleted Tor binary");
+				else LOG.info("Failed to delete Tor binary");
+			}
+		} else if (SDK_INT < 29) {
+			// The binary wasn't extracted at install time. Try to extract it
+			extractLibraryFromApk(TOR_LIB_NAME, extracted);
+		} else {
+			// No point extracting the binary, we won't be allowed to execute it
+			throw new FileNotFoundException(torLib.getAbsolutePath());
+		}
+	}
+
+	@Override
+	protected void installObfs4Executable() throws IOException {
+		File extracted = super.getObfs4ExecutableFile();
+		if (obfs4Lib.exists()) {
+			// If an older version left behind an obfs4 binary, delete it
+			if (extracted.exists()) {
+				if (extracted.delete()) LOG.info("Deleted obfs4 binary");
+				else LOG.info("Failed to delete obfs4 binary");
+			}
+		} else if (SDK_INT < 29) {
+			// The binary wasn't extracted at install time. Try to extract it
+			extractLibraryFromApk(OBFS4_LIB_NAME, extracted);
+		} else {
+			// No point extracting the binary, we won't be allowed to execute it
+			throw new FileNotFoundException(obfs4Lib.getAbsolutePath());
+		}
+	}
+
+	private void extractLibraryFromApk(String libName, File dest)
+			throws IOException {
+		File sourceDir = new File(app.getApplicationInfo().sourceDir);
+		if (sourceDir.isFile()) {
+			// Look for other APK files in the same directory, if we're allowed
+			File parent = sourceDir.getParentFile();
+			if (parent != null) sourceDir = parent;
+		}
+		List<String> libPaths = getSupportedLibraryPaths(libName);
+		for (File apk : findApkFiles(sourceDir)) {
+			ZipInputStream zin = new ZipInputStream(new FileInputStream(apk));
+			for (ZipEntry e = zin.getNextEntry(); e != null;
+					e = zin.getNextEntry()) {
+				if (libPaths.contains(e.getName())) {
+					if (LOG.isLoggable(INFO)) {
+						LOG.info("Extracting " + e.getName()
+								+ " from " + apk.getAbsolutePath());
+					}
+					extract(zin, dest); // Zip input stream will be closed
+					return;
+				}
+			}
+			zin.close();
+		}
+		throw new FileNotFoundException(libName);
+	}
+
+	/**
+	 * Returns all files with the extension .apk or .APK under the given root.
+	 */
+	private List<File> findApkFiles(File root) {
+		List<File> files = new ArrayList<>();
+		findApkFiles(root, files);
+		return files;
+	}
+
+	private void findApkFiles(File f, List<File> files) {
+		if (f.isFile() && f.getName().toLowerCase().endsWith(".apk")) {
+			files.add(f);
+		} else if (f.isDirectory()) {
+			File[] children = f.listFiles();
+			if (children != null) {
+				for (File child : children) findApkFiles(child, files);
+			}
+		}
+	}
+
+	/**
+	 * Returns the paths at which libraries with the given name would be found
+	 * inside an APK file, for all architectures supported by the device, in
+	 * order of preference.
+	 */
+	private List<String> getSupportedLibraryPaths(String libName) {
+		List<String> architectures = new ArrayList<>();
+		for (String abi : AndroidUtils.getSupportedArchitectures()) {
+			if (LIBRARY_ARCHITECTURES.contains(abi)) {
+				architectures.add("lib/" + abi + "/" + libName);
+			}
+		}
+		return architectures;
+	}
 }

bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/AndroidTorPluginFactory.java

@@ -1,28 +1,33 @@
 package org.briarproject.bramble.plugin.tor;
 
-import android.content.Context;
+import android.app.Application;
 
 import org.briarproject.bramble.api.battery.BatteryManager;
 import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.network.NetworkManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.BackoffFactory;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TorConstants;
+import org.briarproject.bramble.api.plugin.TorDirectory;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
+import org.briarproject.bramble.api.system.AndroidWakeLockManager;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.api.system.ResourceProvider;
+import org.briarproject.bramble.api.system.WakefulIoExecutor;
 import org.briarproject.bramble.util.AndroidUtils;
 
+import java.io.File;
 import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
 import java.util.logging.Logger;
 
 import javax.annotation.concurrent.Immutable;
+import javax.inject.Inject;
 import javax.net.SocketFactory;
 
 @Immutable
@@ -38,9 +43,8 @@ public class AndroidTorPluginFactory implements DuplexPluginFactory {
 	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
 	private static final double BACKOFF_BASE = 1.2;
 
-	private final Executor ioExecutor;
+	private final Executor ioExecutor, wakefulIoExecutor;
-	private final ScheduledExecutorService scheduler;
+	private final Application app;
-	private final Context appContext;
 	private final NetworkManager networkManager;
 	private final LocationUtils locationUtils;
 	private final EventBus eventBus;
@@ -49,18 +53,28 @@ public class AndroidTorPluginFactory implements DuplexPluginFactory {
 	private final ResourceProvider resourceProvider;
 	private final CircumventionProvider circumventionProvider;
 	private final BatteryManager batteryManager;
+	private final AndroidWakeLockManager wakeLockManager;
 	private final Clock clock;
+	private final File torDirectory;
 
-	public AndroidTorPluginFactory(Executor ioExecutor,
+	@Inject
-			ScheduledExecutorService scheduler, Context appContext,
+	public AndroidTorPluginFactory(@IoExecutor Executor ioExecutor,
-			NetworkManager networkManager, LocationUtils locationUtils,
+			@WakefulIoExecutor Executor wakefulIoExecutor,
-			EventBus eventBus, SocketFactory torSocketFactory,
+			Application app,
-			BackoffFactory backoffFactory, ResourceProvider resourceProvider,
+			NetworkManager networkManager,
+			LocationUtils locationUtils,
+			EventBus eventBus,
+			SocketFactory torSocketFactory,
+			BackoffFactory backoffFactory,
+			ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
-			BatteryManager batteryManager, Clock clock) {
+			BatteryManager batteryManager,
+			AndroidWakeLockManager wakeLockManager,
+			Clock clock,
+			@TorDirectory File torDirectory) {
 		this.ioExecutor = ioExecutor;
-		this.scheduler = scheduler;
+		this.wakefulIoExecutor = wakefulIoExecutor;
-		this.appContext = appContext;
+		this.app = app;
 		this.networkManager = networkManager;
 		this.locationUtils = locationUtils;
 		this.eventBus = eventBus;
@@ -69,7 +83,9 @@ public class AndroidTorPluginFactory implements DuplexPluginFactory {
 		this.resourceProvider = resourceProvider;
 		this.circumventionProvider = circumventionProvider;
 		this.batteryManager = batteryManager;
+		this.wakeLockManager = wakeLockManager;
 		this.clock = clock;
+		this.torDirectory = torDirectory;
 	}
 
 	@Override
@@ -112,11 +128,12 @@ public class AndroidTorPluginFactory implements DuplexPluginFactory {
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		TorRendezvousCrypto torRendezvousCrypto = new TorRendezvousCryptoImpl();
-		AndroidTorPlugin plugin = new AndroidTorPlugin(ioExecutor, scheduler,
+		AndroidTorPlugin plugin = new AndroidTorPlugin(ioExecutor,
-				appContext, networkManager, locationUtils, torSocketFactory,
+				wakefulIoExecutor, app, networkManager, locationUtils,
-				clock, resourceProvider, circumventionProvider, batteryManager,
+				torSocketFactory, clock, resourceProvider,
+				circumventionProvider, batteryManager, wakeLockManager,
 				backoff, torRendezvousCrypto, callback, architecture,
-				MAX_LATENCY, MAX_IDLE_TIME);
+				MAX_LATENCY, MAX_IDLE_TIME, torDirectory);
 		eventBus.addListener(plugin);
 		return plugin;
 	}

bramble-android/src/main/java/org/briarproject/bramble/system/AlarmConstants.java

@@ -0,0 +1,18 @@
+package org.briarproject.bramble.system;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+@NotNullByDefault
+interface AlarmConstants {
+
+	/**
+	 * Request code for the broadcast intent attached to the periodic alarm.
+	 */
+	int REQUEST_ALARM = 1;
+
+	/**
+	 * Key for storing the process ID in the extras of the periodic alarm's
+	 * intent. This allows us to ignore alarms scheduled by dead processes.
+	 */
+	String EXTRA_PID = "org.briarproject.bramble.EXTRA_PID";
+}

bramble-android/src/main/java/org/briarproject/bramble/system/AlarmReceiver.java

@@ -0,0 +1,17 @@
+package org.briarproject.bramble.system;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+
+import org.briarproject.bramble.BrambleApplication;
+
+public class AlarmReceiver extends BroadcastReceiver {
+
+	@Override
+	public void onReceive(Context ctx, Intent intent) {
+		BrambleApplication app =
+				(BrambleApplication) ctx.getApplicationContext();
+		app.getBrambleAppComponent().alarmListener().onAlarm(intent);
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/system/AndroidSecureRandomProvider.java

@@ -6,8 +6,6 @@ import android.bluetooth.BluetoothAdapter;
 import android.bluetooth.BluetoothDevice;
 import android.content.ContentResolver;
 import android.content.Context;
-import android.net.wifi.WifiConfiguration;
-import android.net.wifi.WifiManager;
 import android.os.Build;
 import android.os.Parcel;
 import android.os.StrictMode;
@@ -17,12 +15,10 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.io.DataOutputStream;
 import java.io.IOException;
-import java.util.List;
 
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
-import static android.content.Context.WIFI_SERVICE;
 import static android.os.Build.VERSION.SDK_INT;
 import static android.provider.Settings.Secure.ANDROID_ID;
 
@@ -52,15 +48,6 @@ class AndroidSecureRandomProvider extends UnixSecureRandomProvider {
 		String id = Settings.Secure.getString(contentResolver, ANDROID_ID);
 		if (id != null) out.writeUTF(id);
 		Parcel parcel = Parcel.obtain();
-		WifiManager wm = (WifiManager) appContext.getApplicationContext()
-				.getSystemService(WIFI_SERVICE);
-		if (wm != null) {
-			List<WifiConfiguration> configs = wm.getConfiguredNetworks();
-			if (configs != null) {
-				for (WifiConfiguration config : configs)
-					parcel.writeParcelable(config, 0);
-			}
-		}
 		BluetoothAdapter bt = BluetoothAdapter.getDefaultAdapter();
 		if (bt != null) {
 			for (BluetoothDevice device : bt.getBondedDevices())

bramble-android/src/main/java/org/briarproject/bramble/system/AndroidSystemModule.java

@@ -1,12 +1,17 @@
 package org.briarproject.bramble.system;
 
 import org.briarproject.bramble.api.event.EventExecutor;
+import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.bramble.api.system.AndroidWakeLockManager;
 import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.api.system.ResourceProvider;
 import org.briarproject.bramble.api.system.SecureRandomProvider;
 
 import java.util.concurrent.Executor;
+import java.util.concurrent.RejectedExecutionHandler;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledThreadPoolExecutor;
 
 import javax.inject.Singleton;
 
@@ -16,6 +21,23 @@ import dagger.Provides;
 @Module
 public class AndroidSystemModule {
 
+	private final ScheduledExecutorService scheduledExecutorService;
+
+	public AndroidSystemModule() {
+		// Discard tasks that are submitted during shutdown
+		RejectedExecutionHandler policy =
+				new ScheduledThreadPoolExecutor.DiscardPolicy();
+		scheduledExecutorService = new ScheduledThreadPoolExecutor(1, policy);
+	}
+
+	@Provides
+	@Singleton
+	ScheduledExecutorService provideScheduledExecutorService(
+			LifecycleManager lifecycleManager) {
+		lifecycleManager.registerForShutdown(scheduledExecutorService);
+		return scheduledExecutorService;
+	}
+
 	@Provides
 	@Singleton
 	SecureRandomProvider provideSecureRandomProvider(
@@ -47,4 +69,11 @@ public class AndroidSystemModule {
 	ResourceProvider provideResourceProvider(AndroidResourceProvider provider) {
 		return provider;
 	}
+
+	@Provides
+	@Singleton
+	AndroidWakeLockManager provideWakeLockManager(
+			AndroidWakeLockManagerImpl wakeLockManager) {
+		return wakeLockManager;
+	}
 }

bramble-android/src/main/java/org/briarproject/bramble/system/AndroidTaskScheduler.java

@@ -0,0 +1,242 @@
+package org.briarproject.bramble.system;
+
+import android.annotation.TargetApi;
+import android.app.AlarmManager;
+import android.app.Application;
+import android.app.PendingIntent;
+import android.content.Intent;
+import android.os.Process;
+import android.os.SystemClock;
+
+import org.briarproject.bramble.api.lifecycle.Service;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.AlarmListener;
+import org.briarproject.bramble.api.system.AndroidWakeLockManager;
+import org.briarproject.bramble.api.system.TaskScheduler;
+import org.briarproject.bramble.api.system.Wakeful;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.PriorityQueue;
+import java.util.Queue;
+import java.util.concurrent.Executor;
+import java.util.concurrent.Future;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.logging.Logger;
+
+import javax.annotation.concurrent.GuardedBy;
+import javax.annotation.concurrent.ThreadSafe;
+
+import static android.app.AlarmManager.ELAPSED_REALTIME_WAKEUP;
+import static android.app.AlarmManager.INTERVAL_FIFTEEN_MINUTES;
+import static android.app.PendingIntent.FLAG_CANCEL_CURRENT;
+import static android.content.Context.ALARM_SERVICE;
+import static android.os.Build.VERSION.SDK_INT;
+import static java.util.Objects.requireNonNull;
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.system.AlarmConstants.EXTRA_PID;
+import static org.briarproject.bramble.system.AlarmConstants.REQUEST_ALARM;
+
+@ThreadSafe
+@NotNullByDefault
+class AndroidTaskScheduler implements TaskScheduler, Service, AlarmListener {
+
+	private static final Logger LOG =
+			getLogger(AndroidTaskScheduler.class.getName());
+
+	private static final long ALARM_MS = INTERVAL_FIFTEEN_MINUTES;
+
+	private final Application app;
+	private final AndroidWakeLockManager wakeLockManager;
+	private final ScheduledExecutorService scheduledExecutorService;
+	private final AlarmManager alarmManager;
+
+	private final Object lock = new Object();
+	@GuardedBy("lock")
+	private final Queue<ScheduledTask> tasks = new PriorityQueue<>();
+
+	AndroidTaskScheduler(Application app,
+			AndroidWakeLockManager wakeLockManager,
+			ScheduledExecutorService scheduledExecutorService) {
+		this.app = app;
+		this.wakeLockManager = wakeLockManager;
+		this.scheduledExecutorService = scheduledExecutorService;
+		alarmManager = (AlarmManager)
+				requireNonNull(app.getSystemService(ALARM_SERVICE));
+	}
+
+	@Override
+	public void startService() {
+		scheduleAlarm();
+	}
+
+	@Override
+	public void stopService() {
+		cancelAlarm();
+	}
+
+	@Override
+	public Cancellable schedule(Runnable task, Executor executor, long delay,
+			TimeUnit unit) {
+		AtomicBoolean cancelled = new AtomicBoolean(false);
+		return schedule(task, executor, delay, unit, cancelled);
+	}
+
+	@Override
+	public Cancellable scheduleWithFixedDelay(Runnable task, Executor executor,
+			long delay, long interval, TimeUnit unit) {
+		AtomicBoolean cancelled = new AtomicBoolean(false);
+		return scheduleWithFixedDelay(task, executor, delay, interval, unit,
+				cancelled);
+	}
+
+	@Override
+	public void onAlarm(Intent intent) {
+		wakeLockManager.runWakefully(() -> {
+			int extraPid = intent.getIntExtra(EXTRA_PID, -1);
+			int currentPid = Process.myPid();
+			if (extraPid == currentPid) {
+				LOG.info("Alarm");
+				rescheduleAlarm();
+				runDueTasks();
+			} else if (LOG.isLoggable(INFO)) {
+				LOG.info("Ignoring alarm with PID " + extraPid
+						+ ", current PID is " + currentPid);
+			}
+		}, "TaskAlarm");
+	}
+
+	private Cancellable schedule(Runnable task, Executor executor, long delay,
+			TimeUnit unit, AtomicBoolean cancelled) {
+		long now = SystemClock.elapsedRealtime();
+		long dueMillis = now + MILLISECONDS.convert(delay, unit);
+		Runnable wakeful = () ->
+				wakeLockManager.executeWakefully(task, executor, "TaskHandoff");
+		Future<?> check = scheduleCheckForDueTasks(delay, unit);
+		ScheduledTask s = new ScheduledTask(wakeful, dueMillis, check,
+				cancelled);
+		synchronized (lock) {
+			tasks.add(s);
+		}
+		return s;
+	}
+
+	private Cancellable scheduleWithFixedDelay(Runnable task, Executor executor,
+			long delay, long interval, TimeUnit unit, AtomicBoolean cancelled) {
+		// All executions of this periodic task share a cancelled flag
+		Runnable wrapped = () -> {
+			task.run();
+			scheduleWithFixedDelay(task, executor, interval, interval, unit,
+					cancelled);
+		};
+		return schedule(wrapped, executor, delay, unit, cancelled);
+	}
+
+	private Future<?> scheduleCheckForDueTasks(long delay, TimeUnit unit) {
+		Runnable wakeful = () -> wakeLockManager.runWakefully(
+				this::runDueTasks, "TaskScheduler");
+		return scheduledExecutorService.schedule(wakeful, delay, unit);
+	}
+
+	@Wakeful
+	private void runDueTasks() {
+		long now = SystemClock.elapsedRealtime();
+		List<ScheduledTask> due = new ArrayList<>();
+		synchronized (lock) {
+			while (true) {
+				ScheduledTask s = tasks.peek();
+				if (s == null || s.dueMillis > now) break;
+				due.add(tasks.remove());
+			}
+		}
+		if (LOG.isLoggable(INFO)) {
+			LOG.info("Running " + due.size() + " due tasks");
+		}
+		for (ScheduledTask s : due) {
+			if (LOG.isLoggable(INFO)) {
+				LOG.info("Task is " + (now - s.dueMillis) + " ms overdue");
+			}
+			s.run();
+		}
+	}
+
+	private void scheduleAlarm() {
+		if (SDK_INT >= 23) scheduleIdleAlarm();
+		else scheduleInexactRepeatingAlarm();
+	}
+
+	private void rescheduleAlarm() {
+		// If SDK_INT < 23 the alarm repeats automatically
+		if (SDK_INT >= 23) scheduleIdleAlarm();
+	}
+
+	private void cancelAlarm() {
+		alarmManager.cancel(getAlarmPendingIntent());
+	}
+
+	private void scheduleInexactRepeatingAlarm() {
+		alarmManager.setInexactRepeating(ELAPSED_REALTIME_WAKEUP,
+				SystemClock.elapsedRealtime() + ALARM_MS, ALARM_MS,
+				getAlarmPendingIntent());
+	}
+
+	@TargetApi(23)
+	private void scheduleIdleAlarm() {
+		alarmManager.setAndAllowWhileIdle(ELAPSED_REALTIME_WAKEUP,
+				SystemClock.elapsedRealtime() + ALARM_MS,
+				getAlarmPendingIntent());
+	}
+
+	private PendingIntent getAlarmPendingIntent() {
+		Intent i = new Intent(app, AlarmReceiver.class);
+		i.putExtra(EXTRA_PID, android.os.Process.myPid());
+		return PendingIntent.getBroadcast(app, REQUEST_ALARM, i,
+				FLAG_CANCEL_CURRENT);
+	}
+
+	private class ScheduledTask
+			implements Runnable, Cancellable, Comparable<ScheduledTask> {
+
+		private final Runnable task;
+		private final long dueMillis;
+		private final Future<?> check;
+		private final AtomicBoolean cancelled;
+
+		public ScheduledTask(Runnable task, long dueMillis,
+				Future<?> check, AtomicBoolean cancelled) {
+			this.task = task;
+			this.dueMillis = dueMillis;
+			this.check = check;
+			this.cancelled = cancelled;
+		}
+
+		@Override
+		public void run() {
+			if (!cancelled.get()) task.run();
+		}
+
+		@Override
+		public void cancel() {
+			// Cancel any future executions of this task
+			cancelled.set(true);
+			// Cancel the scheduled check for due tasks
+			check.cancel(false);
+			// Remove the task from the queue
+			synchronized (lock) {
+				tasks.remove(this);
+			}
+		}
+
+		@Override
+		public int compareTo(ScheduledTask s) {
+			//noinspection UseCompareMethod
+			if (dueMillis < s.dueMillis) return -1;
+			if (dueMillis > s.dueMillis) return 1;
+			return 0;
+		}
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/system/AndroidTaskSchedulerModule.java

@@ -0,0 +1,49 @@
+package org.briarproject.bramble.system;
+
+import android.app.Application;
+
+import org.briarproject.bramble.api.lifecycle.LifecycleManager;
+import org.briarproject.bramble.api.system.AlarmListener;
+import org.briarproject.bramble.api.system.AndroidWakeLockManager;
+import org.briarproject.bramble.api.system.TaskScheduler;
+
+import java.util.concurrent.ScheduledExecutorService;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+
+import dagger.Module;
+import dagger.Provides;
+
+@Module
+public class AndroidTaskSchedulerModule {
+
+	public static class EagerSingletons {
+		@Inject
+		AndroidTaskScheduler scheduler;
+	}
+
+	@Provides
+	@Singleton
+	AndroidTaskScheduler provideAndroidTaskScheduler(
+			LifecycleManager lifecycleManager, Application app,
+			AndroidWakeLockManager wakeLockManager,
+			ScheduledExecutorService scheduledExecutorService) {
+		AndroidTaskScheduler scheduler = new AndroidTaskScheduler(app,
+				wakeLockManager, scheduledExecutorService);
+		lifecycleManager.registerService(scheduler);
+		return scheduler;
+	}
+
+	@Provides
+	@Singleton
+	AlarmListener provideAlarmListener(AndroidTaskScheduler scheduler) {
+		return scheduler;
+	}
+
+	@Provides
+	@Singleton
+	TaskScheduler provideTaskScheduler(AndroidTaskScheduler scheduler) {
+		return scheduler;
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/system/AndroidWakeLockImpl.java

@@ -0,0 +1,74 @@
+package org.briarproject.bramble.system;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.AndroidWakeLock;
+
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.logging.Logger;
+
+import javax.annotation.concurrent.GuardedBy;
+import javax.annotation.concurrent.ThreadSafe;
+
+import static java.util.logging.Level.FINE;
+import static java.util.logging.Logger.getLogger;
+
+/**
+ * A wrapper around a {@link SharedWakeLock} that provides the more convenient
+ * semantics of {@link AndroidWakeLock} (i.e. calls to acquire() and release()
+ * don't need to be balanced).
+ */
+@ThreadSafe
+@NotNullByDefault
+class AndroidWakeLockImpl implements AndroidWakeLock {
+
+	private static final Logger LOG =
+			getLogger(AndroidWakeLockImpl.class.getName());
+
+	private static final AtomicInteger INSTANCE_ID = new AtomicInteger(0);
+
+	private final SharedWakeLock sharedWakeLock;
+	private final String tag;
+
+	private final Object lock = new Object();
+	@GuardedBy("lock")
+	private boolean held = false;
+
+	AndroidWakeLockImpl(SharedWakeLock sharedWakeLock, String tag) {
+		this.sharedWakeLock = sharedWakeLock;
+		this.tag = tag + "_" + INSTANCE_ID.getAndIncrement();
+	}
+
+	@Override
+	public void acquire() {
+		synchronized (lock) {
+			if (held) {
+				if (LOG.isLoggable(FINE)) {
+					LOG.fine(tag + " already acquired");
+				}
+			} else {
+				if (LOG.isLoggable(FINE)) {
+					LOG.fine(tag + " acquiring shared wake lock");
+				}
+				held = true;
+				sharedWakeLock.acquire();
+			}
+		}
+	}
+
+	@Override
+	public void release() {
+		synchronized (lock) {
+			if (held) {
+				if (LOG.isLoggable(FINE)) {
+					LOG.fine(tag + " releasing shared wake lock");
+				}
+				held = false;
+				sharedWakeLock.release();
+			} else {
+				if (LOG.isLoggable(FINE)) {
+					LOG.fine(tag + " already released");
+				}
+			}
+		}
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/system/AndroidWakeLockManagerImpl.java

@@ -0,0 +1,119 @@
+package org.briarproject.bramble.system;
+
+import android.app.Application;
+import android.content.Context;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.os.PowerManager;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.AndroidWakeLock;
+import org.briarproject.bramble.api.system.AndroidWakeLockManager;
+
+import java.util.concurrent.Executor;
+import java.util.concurrent.ScheduledExecutorService;
+
+import javax.inject.Inject;
+
+import static android.content.Context.POWER_SERVICE;
+import static android.os.PowerManager.PARTIAL_WAKE_LOCK;
+import static java.util.concurrent.TimeUnit.MINUTES;
+import static java.util.concurrent.TimeUnit.SECONDS;
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
+
+@NotNullByDefault
+class AndroidWakeLockManagerImpl implements AndroidWakeLockManager {
+
+	/**
+	 * How often to replace the wake lock.
+	 */
+	private static final long LOCK_DURATION_MS = MINUTES.toMillis(1);
+
+	/**
+	 * Automatically release the lock this many milliseconds after it's due
+	 * to have been replaced and released.
+	 */
+	private static final long SAFETY_MARGIN_MS = SECONDS.toMillis(30);
+
+	private final SharedWakeLock sharedWakeLock;
+
+	@Inject
+	AndroidWakeLockManagerImpl(Application app,
+			ScheduledExecutorService scheduledExecutorService) {
+		PowerManager powerManager = (PowerManager)
+				requireNonNull(app.getSystemService(POWER_SERVICE));
+		String tag = getWakeLockTag(app);
+		sharedWakeLock = new RenewableWakeLock(powerManager,
+				scheduledExecutorService, PARTIAL_WAKE_LOCK, tag,
+				LOCK_DURATION_MS, SAFETY_MARGIN_MS);
+	}
+
+	@Override
+	public AndroidWakeLock createWakeLock(String tag) {
+		return new AndroidWakeLockImpl(sharedWakeLock, tag);
+	}
+
+	@Override
+	public void runWakefully(Runnable r, String tag) {
+		AndroidWakeLock wakeLock = createWakeLock(tag);
+		wakeLock.acquire();
+		try {
+			r.run();
+		} finally {
+			wakeLock.release();
+		}
+	}
+
+	@Override
+	public void executeWakefully(Runnable r, Executor executor, String tag) {
+		AndroidWakeLock wakeLock = createWakeLock(tag);
+		wakeLock.acquire();
+		try {
+			executor.execute(() -> {
+				try {
+					r.run();
+				} finally {
+					// Release the wake lock if the task throws an exception
+					wakeLock.release();
+				}
+			});
+		} catch (Exception e) {
+			// Release the wake lock if the executor throws an exception when
+			// we submit the task (in which case the release() call above won't
+			// happen)
+			wakeLock.release();
+			throw e;
+		}
+	}
+
+	@Override
+	public void executeWakefully(Runnable r, String tag) {
+		AndroidWakeLock wakeLock = createWakeLock(tag);
+		wakeLock.acquire();
+		try {
+			new Thread(() -> {
+				try {
+					r.run();
+				} finally {
+					wakeLock.release();
+				}
+			}).start();
+		} catch (Exception e) {
+			wakeLock.release();
+			throw e;
+		}
+	}
+
+	private String getWakeLockTag(Context ctx) {
+		PackageManager pm = ctx.getPackageManager();
+		for (PackageInfo info : pm.getInstalledPackages(0)) {
+			String name = info.packageName.toLowerCase();
+			if (name.startsWith("com.huawei.powergenie")) {
+				return "LocationManagerService";
+			} else if (name.startsWith("com.evenwell.powermonitor")) {
+				return "AudioIn";
+			}
+		}
+		return ctx.getPackageName();
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/system/AndroidWakefulIoExecutorModule.java

@@ -0,0 +1,23 @@
+package org.briarproject.bramble.system;
+
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
+import org.briarproject.bramble.api.system.AndroidWakeLockManager;
+import org.briarproject.bramble.api.system.WakefulIoExecutor;
+
+import java.util.concurrent.Executor;
+
+import dagger.Module;
+import dagger.Provides;
+
+@Module
+public
+class AndroidWakefulIoExecutorModule {
+
+	@Provides
+	@WakefulIoExecutor
+	Executor provideWakefulIoExecutor(@IoExecutor Executor ioExecutor,
+			AndroidWakeLockManager wakeLockManager) {
+		return r -> wakeLockManager.executeWakefully(r, ioExecutor,
+				"WakefulIoExecutor");
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/system/RenewableWakeLock.java

@@ -0,0 +1,130 @@
+package org.briarproject.bramble.system;
+
+import android.os.PowerManager;
+import android.os.PowerManager.WakeLock;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.util.concurrent.Future;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.logging.Logger;
+
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.GuardedBy;
+import javax.annotation.concurrent.ThreadSafe;
+
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
+import static java.util.logging.Level.FINE;
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
+
+@ThreadSafe
+@NotNullByDefault
+class RenewableWakeLock implements SharedWakeLock {
+
+	private static final Logger LOG =
+			getLogger(RenewableWakeLock.class.getName());
+
+	private final PowerManager powerManager;
+	private final ScheduledExecutorService scheduledExecutorService;
+	private final int levelAndFlags;
+	private final String tag;
+	private final long durationMs, safetyMarginMs;
+
+	private final Object lock = new Object();
+	@GuardedBy("lock")
+	@Nullable
+	private WakeLock wakeLock;
+	@GuardedBy("lock")
+	@Nullable
+	private Future<?> future;
+	@GuardedBy("lock")
+	private int refCount = 0;
+	@GuardedBy("lock")
+	private long acquired = 0;
+
+	RenewableWakeLock(PowerManager powerManager,
+			ScheduledExecutorService scheduledExecutorService,
+			int levelAndFlags,
+			String tag,
+			long durationMs,
+			long safetyMarginMs) {
+		this.powerManager = powerManager;
+		this.scheduledExecutorService = scheduledExecutorService;
+		this.levelAndFlags = levelAndFlags;
+		this.tag = tag;
+		this.durationMs = durationMs;
+		this.safetyMarginMs = safetyMarginMs;
+	}
+
+	@Override
+	public void acquire() {
+		synchronized (lock) {
+			refCount++;
+			if (refCount == 1) {
+				if (LOG.isLoggable(INFO)) {
+					LOG.info("Acquiring wake lock " + tag);
+				}
+				wakeLock = powerManager.newWakeLock(levelAndFlags, tag);
+				// We do our own reference counting so we can replace the lock
+				// TODO: Check whether using a ref-counted wake lock affects
+				//  power management apps
+				wakeLock.setReferenceCounted(false);
+				wakeLock.acquire(durationMs + safetyMarginMs);
+				future = scheduledExecutorService.schedule(this::renew,
+						durationMs, MILLISECONDS);
+				acquired = android.os.SystemClock.elapsedRealtime();
+			} else if (LOG.isLoggable(FINE)) {
+				LOG.fine("Wake lock " + tag + " has " + refCount + " holders");
+			}
+		}
+	}
+
+	private void renew() {
+		if (LOG.isLoggable(INFO)) LOG.info("Renewing wake lock " + tag);
+		synchronized (lock) {
+			if (wakeLock == null) {
+				LOG.info("Already released");
+				return;
+			}
+			if (LOG.isLoggable(FINE)) {
+				LOG.fine("Wake lock " + tag + " has " + refCount + " holders");
+			}
+			long now = android.os.SystemClock.elapsedRealtime();
+			long expiry = acquired + durationMs + safetyMarginMs;
+			if (now > expiry && LOG.isLoggable(WARNING)) {
+				LOG.warning("Wake lock expired " + (now - expiry) + " ms ago");
+			}
+			WakeLock oldWakeLock = wakeLock;
+			wakeLock = powerManager.newWakeLock(levelAndFlags, tag);
+			wakeLock.setReferenceCounted(false);
+			wakeLock.acquire(durationMs + safetyMarginMs);
+			oldWakeLock.release();
+			future = scheduledExecutorService.schedule(this::renew, durationMs,
+					MILLISECONDS);
+			acquired = now;
+		}
+	}
+
+	@Override
+	public void release() {
+		synchronized (lock) {
+			refCount--;
+			if (refCount == 0) {
+				if (LOG.isLoggable(INFO)) {
+					LOG.info("Releasing wake lock " + tag);
+				}
+				requireNonNull(future).cancel(false);
+				future = null;
+				requireNonNull(wakeLock).release();
+				wakeLock = null;
+				acquired = 0;
+			} else if (LOG.isLoggable(FINE)) {
+				LOG.fine("Wake lock " + tag + " has " + refCount + " holders");
+			}
+		}
+	}
+}
+

bramble-android/src/main/java/org/briarproject/bramble/system/SharedWakeLock.java

@@ -0,0 +1,22 @@
+package org.briarproject.bramble.system;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.AndroidWakeLock;
+
+@NotNullByDefault
+interface SharedWakeLock {
+
+	/**
+	 * Acquires the wake lock. This increments the wake lock's reference count,
+	 * so unlike {@link AndroidWakeLock#acquire()} every call to this method
+	 * must be followed by a balancing call to {@link #release()}.
+	 */
+	void acquire();
+
+	/**
+	 * Releases the wake lock. This decrements the wake lock's reference count,
+	 * so unlike {@link AndroidWakeLock#release()} every call to this method
+	 * must follow a balancing call to {@link #acquire()}.
+	 */
+	void release();
+}

bramble-android/src/main/java/org/briarproject/bramble/util/AndroidUtils.java

@@ -3,8 +3,6 @@ package org.briarproject.bramble.util;
 import android.annotation.SuppressLint;
 import android.bluetooth.BluetoothAdapter;
 import android.content.Context;
-import android.content.pm.PackageInfo;
-import android.content.pm.PackageManager;
 import android.os.Build;
 import android.provider.Settings;
 
@@ -119,17 +117,4 @@ public class AndroidUtils {
 		if (SDK_INT < 24) return new String[] {"image/jpeg", "image/png"};
 		else return new String[] {"image/jpeg", "image/png", "image/gif"};
 	}
-
-	public static String getWakeLockTag(Context ctx) {
-		PackageManager pm = ctx.getPackageManager();
-		for (PackageInfo info : pm.getInstalledPackages(0)) {
-			String name = info.packageName.toLowerCase();
-			if (name.startsWith("com.huawei.powergenie")) {
-				return "LocationManagerService";
-			} else if (name.startsWith("com.evenwell.powermonitor")) {
-				return "AudioIn";
-			}
-		}
-		return ctx.getPackageName();
-	}
 }

bramble-android/src/main/java/org/briarproject/bramble/util/RenewableWakeLock.java

@@ -1,100 +0,0 @@
-package org.briarproject.bramble.util;
-
-import android.os.PowerManager;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledFuture;
-import java.util.concurrent.TimeUnit;
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.ThreadSafe;
-
-import static java.util.concurrent.TimeUnit.MILLISECONDS;
-import static java.util.logging.Level.INFO;
-
-@ThreadSafe
-@NotNullByDefault
-public class RenewableWakeLock {
-
-	private static final Logger LOG =
-			Logger.getLogger(RenewableWakeLock.class.getName());
-
-	/**
-	 * Automatically release the lock this many milliseconds after it's due
-	 * to have been replaced and released.
-	 */
-	private static final int SAFETY_MARGIN_MS = 10_000;
-
-	private final PowerManager powerManager;
-	private final ScheduledExecutorService scheduler;
-	private final int levelAndFlags;
-	private final String tag;
-	private final long durationMs;
-	private final Runnable renewTask;
-
-	private final Object lock = new Object();
-	@Nullable
-	private PowerManager.WakeLock wakeLock; // Locking: lock
-	@Nullable
-	private ScheduledFuture future; // Locking: lock
-
-	public RenewableWakeLock(PowerManager powerManager,
-			ScheduledExecutorService scheduler, int levelAndFlags, String tag,
-			long duration, TimeUnit timeUnit) {
-		this.powerManager = powerManager;
-		this.scheduler = scheduler;
-		this.levelAndFlags = levelAndFlags;
-		this.tag = tag;
-		durationMs = MILLISECONDS.convert(duration, timeUnit);
-		renewTask = this::renew;
-	}
-
-	public void acquire() {
-		if (LOG.isLoggable(INFO)) LOG.info("Acquiring wake lock " + tag);
-		synchronized (lock) {
-			if (wakeLock != null) {
-				LOG.info("Already acquired");
-				return;
-			}
-			wakeLock = powerManager.newWakeLock(levelAndFlags, tag);
-			wakeLock.setReferenceCounted(false);
-			wakeLock.acquire(durationMs + SAFETY_MARGIN_MS);
-			future = scheduler.schedule(renewTask, durationMs, MILLISECONDS);
-		}
-	}
-
-	private void renew() {
-		if (LOG.isLoggable(INFO)) LOG.info("Renewing wake lock " + tag);
-		synchronized (lock) {
-			if (wakeLock == null) {
-				LOG.info("Already released");
-				return;
-			}
-			PowerManager.WakeLock oldWakeLock = wakeLock;
-			wakeLock = powerManager.newWakeLock(levelAndFlags, tag);
-			wakeLock.setReferenceCounted(false);
-			wakeLock.acquire(durationMs + SAFETY_MARGIN_MS);
-			oldWakeLock.release();
-			future = scheduler.schedule(renewTask, durationMs, MILLISECONDS);
-		}
-	}
-
-	public void release() {
-		if (LOG.isLoggable(INFO)) LOG.info("Releasing wake lock " + tag);
-		synchronized (lock) {
-			if (wakeLock == null) {
-				LOG.info("Already released");
-				return;
-			}
-			if (future == null) throw new AssertionError();
-			future.cancel(false);
-			future = null;
-			wakeLock.release();
-			wakeLock = null;
-		}
-	}
-}
-

bramble-android/witness.gradle

@@ -1,33 +1,36 @@
 dependencyVerification {
     verify = [
         'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
-        'com.android.tools.analytics-library:protos:26.5.1:protos-26.5.1.jar:8dde1130725461fe827f2a343d353f2b51e8870661fc860d7d5ebddb097ead4e',
+        'com.android.tools.analytics-library:protos:27.1.1:protos-27.1.1.jar:13f77e73762e58ab372d140b3a6be6903aea9775b62dd14fbc62d4cc7069c9a4',
-        'com.android.tools.analytics-library:shared:26.5.1:shared-26.5.1.jar:ccc2f3b00ec17b11401610ba68553544fc8fc517120e84439ac6eb86b875e18d',
+        'com.android.tools.analytics-library:shared:27.1.1:shared-27.1.1.jar:82930a52001410e97d809930b670f4de3002286975f046b9de5f6b777b06d366',
-        'com.android.tools.analytics-library:tracker:26.5.1:tracker-26.5.1.jar:3a76984c0fe2e847ca7a8b35b4780ef0447a9d1666946cb8e60466318e0ab5ae',
+        'com.android.tools.analytics-library:tracker:27.1.1:tracker-27.1.1.jar:31bc5a00be0055bac89c9b2f34751883e987cd89e3ac1783720645c164f591d9',
-        'com.android.tools.build:aapt2-proto:0.4.0:aapt2-proto-0.4.0.jar:fac0435e08898f89eeeb9ca236bea707155ff816c12205ced285ad53604133ca',
+        'com.android.tools.build:aapt2-proto:4.1.0-alpha01-6193524:aapt2-proto-4.1.0-alpha01-6193524.jar:17e75523e1e92dd4f222c7368ee41df9e964a508232f591e265d0c499baf9dca',
-        'com.android.tools.build:apksig:3.5.1:apksig-3.5.1.jar:1fd33e7f009a2a0da766cfeec4211a09f548034b015c289a66d75dd8a9302f4a',
+        'com.android.tools.build:apksig:4.1.1:apksig-4.1.1.jar:e0a69da9e5a03986d608b45bbf954ef0e6a0b3f58c1b8315bd169ec08b279e72',
-        'com.android.tools.build:apkzlib:3.5.1:apkzlib-3.5.1.jar:9f330167cbe973b7db407692f74f4f6453b7ffa5f2048934b06280c2ceee60fa',
+        'com.android.tools.build:apkzlib:4.1.1:apkzlib-4.1.1.jar:ba4b5e419b6be0130eae7f8301c3a551ad3976f487d2e0c6852ebb175ac41127',
-        'com.android.tools.build:builder-model:3.5.1:builder-model-3.5.1.jar:39ea3c82b76b6e0c9f9fa88d93e0edc1dd4a0f1dfae0ef6fbf2d451da47e5450',
+        'com.android.tools.build:builder-model:4.1.1:builder-model-4.1.1.jar:e95c99cc298ad67b8deb6ced99c51abc8f59afebedad044b1a10dde14646a4dd',
-        'com.android.tools.build:builder-test-api:3.5.1:builder-test-api-3.5.1.jar:a1b59305584cbcaa078fdc9cfb80871012755b822dd32e8da19add6f7bbcb762',
+        'com.android.tools.build:builder-test-api:4.1.1:builder-test-api-4.1.1.jar:464f596ab261c051c3847406748e843770dea123f6fa5fee8a9390644e709b7a',
-        'com.android.tools.build:builder:3.5.1:builder-3.5.1.jar:e3a8d382434c5f60990730c4719fc814e85a898a33a1e96c1df8d627d3c6eea6',
+        'com.android.tools.build:builder:4.1.1:builder-4.1.1.jar:0f78d4759d2f7b57b95865522ec34596ba419b9982f3b25e3449213f9c98b80d',
-        'com.android.tools.build:gradle-api:3.5.1:gradle-api-3.5.1.jar:be9b41859bace11998f66b04ed944f87e413f3ad6da3c4665587699da125addc',
+        'com.android.tools.build:gradle-api:4.1.1:gradle-api-4.1.1.jar:d42e6b539e4c1353ad3546e75ec8ce11a017b97481023e8ea18577eefe374358',
-        'com.android.tools.build:manifest-merger:26.5.1:manifest-merger-26.5.1.jar:dcad9ecb967251f4d750f55a4204a2b400e8fbfe5cb930a1d0d5dbe10ae8bdfc',
+        'com.android.tools.build:manifest-merger:27.1.1:manifest-merger-27.1.1.jar:7a45fa143687859bb2e5a961dcf6ee88094d3853de0cb543dc03dbcb0f4b554b',
-        'com.android.tools.ddms:ddmlib:26.5.1:ddmlib-26.5.1.jar:b081aef2a4ed3f4d47cae4cdb128469735f25a114e026d37123bf9ffdec742a8',
+        'com.android.tools.ddms:ddmlib:27.1.1:ddmlib-27.1.1.jar:da6e4bd834b6a85dae8019039849d8bd96933347dfbf460df74913ddade6e40a',
-        'com.android.tools.external.com-intellij:intellij-core:26.5.1:intellij-core-26.5.1.jar:20eced30adc124805bd93488d9cd9d3e33e6bf7b48e9fe5a703d4983f894d450',
+        'com.android.tools.external.com-intellij:intellij-core:27.1.1:intellij-core-27.1.1.jar:2591a7363c4443c59bf9f793730acafce9d6ec3076e2f46716edaf53a41b6fb6',
-        'com.android.tools.external.com-intellij:kotlin-compiler:26.5.1:kotlin-compiler-26.5.1.jar:5aed762dd54875b77ae7018d97c05756ff0c5b9fd02ec595dd396ccd14cc22cb',
+        'com.android.tools.external.com-intellij:kotlin-compiler:27.1.1:kotlin-compiler-27.1.1.jar:5054ae770ba788f110303c65abd6b1fa28eccf52dee1274510e201b2b81885c8',
-        'com.android.tools.external.org-jetbrains:uast:26.5.1:uast-26.5.1.jar:4bc8653d6c0943f40fee963a149e36c6baa45683d2530968a13f5007e3c40740',
+        'com.android.tools.external.org-jetbrains:uast:27.1.1:uast-27.1.1.jar:54cd8f6886a9d2f5641659dd5c91f626629672cd48301f7f0bd6aad9bd448714',
-        'com.android.tools.layoutlib:layoutlib-api:26.5.1:layoutlib-api-26.5.1.jar:88732f11396c427273e515d23042e35633f4fe4295528a99b866aa2adf0efd9c',
+        'com.android.tools.layoutlib:layoutlib-api:27.1.1:layoutlib-api-27.1.1.jar:8a9a22e3b309521ea83b724e5a89cfdac6076f52d675c0e17d77b05527bc0f8c',
-        'com.android.tools.lint:lint-api:26.5.1:lint-api-26.5.1.jar:ec33fcd72bfaf70dd841e03fbfd93f109c2e575aec146067c606689c3972f0de',
+        'com.android.tools.lint:lint-api:27.1.1:lint-api-27.1.1.jar:c1d8176094cb0478786070d40533efb578ebc53529a82f6ef5bee879bdca418b',
-        'com.android.tools.lint:lint-checks:26.5.1:lint-checks-26.5.1.jar:a1b9607d484aaae7a71dcecdc76f8003d8239af226c776894a2cf63f9e6c60d7',
+        'com.android.tools.lint:lint-checks:27.1.1:lint-checks-27.1.1.jar:3899c91e00bd059b40c31a9ca00cd0f8303191947608735ae1b657323693fb61',
-        'com.android.tools.lint:lint-gradle-api:26.5.1:lint-gradle-api-26.5.1.jar:82453fd98a8394cc84ed995c04d2cd744abd1d6589403427ba7eef53115406f3',
+        'com.android.tools.lint:lint-gradle-api:27.1.1:lint-gradle-api-27.1.1.jar:26aa89d38b9825cc73229daa82a68875801c8b8491f30497ce62aff1f206eb0d',
-        'com.android.tools.lint:lint-gradle:26.5.1:lint-gradle-26.5.1.jar:59465b56cf7db77c656d5f8195d721c3d48b6bdd0502d774de335bfe4baff00b',
+        'com.android.tools.lint:lint-gradle:27.1.1:lint-gradle-27.1.1.jar:f7355823ead869f4d28184ba28b7a0c693b507519a2d3705bb9848a0f35b3756',
-        'com.android.tools.lint:lint:26.5.1:lint-26.5.1.jar:336e4b04ec6f8b0f25879131b7a7862d77df83a1879ee5b71be26128755f8e2e',
+        'com.android.tools.lint:lint-model:27.1.1:lint-model-27.1.1.jar:bc23c0c413bdfca59dac2cd56b870d8360d009e9ec0d365e71f774bcf127971d',
-        'com.android.tools:annotations:26.5.1:annotations-26.5.1.jar:2c43c82f8c59d8f7a61e3239e1a2dc9f69dc342ec09af9b7c9f69b25337c0b6e',
+        'com.android.tools.lint:lint:27.1.1:lint-27.1.1.jar:2f6038a5398a42bd591883c3f5e5894f4ec52ca1c3683bf94fa8553c1700af81',
-        'com.android.tools:common:26.5.1:common-26.5.1.jar:eccfa54486ed54c4e3123cc42195d023bd0dd21bcd2f0e4868e8c6fc70f8ef6b',
+        'com.android.tools:annotations:27.1.1:annotations-27.1.1.jar:ff28c504d2acb9fd1a5ffbd97ae85cf59ee18c76927525aad250509bccf2cab1',
-        'com.android.tools:dvlib:26.5.1:dvlib-26.5.1.jar:46f93ad498b4756e7d867d2fe38c38890a80e7407a4ae459e4a8c8d5c5aeacfe',
+        'com.android.tools:common:27.1.1:common-27.1.1.jar:63d9a2a9ad6d278db319f3749b9f50bdf5457ef7020074a1bebe124e714b535c',
-        'com.android.tools:repository:26.5.1:repository-26.5.1.jar:2b3ee791aa4c3e8ce60498c161a27ca7228816fc630eed4d9f25f2f36a106dce',
+        'com.android.tools:dvlib:27.1.1:dvlib-27.1.1.jar:998a54201fc1cefee5f2399215e95c42b1f64f9e1d8f4452eb8255c68ba5440f',
-        'com.android.tools:sdk-common:26.5.1:sdk-common-26.5.1.jar:365f749676c3574676fd465177c8a492f340816db2b520d6ed114d3b6e77bea7',
+        'com.android.tools:repository:27.1.1:repository-27.1.1.jar:d25b74ccabf4d876903efb375e9af6fb380d8ae0445bb74bbdcc225c1e37fa1d',
-        'com.android.tools:sdklib:26.5.1:sdklib-26.5.1.jar:007da104afb27c8c682a1628023fe9ec438249c8d15ef0fd6624c5bb8e23b696',
+        'com.android.tools:sdk-common:27.1.1:sdk-common-27.1.1.jar:4473ae97d0ef7061ee1de61041d5aa97405ae08e44c09cf7bb278b42e4b97c7c',
+        'com.android.tools:sdklib:27.1.1:sdklib-27.1.1.jar:08e6b83961ac9724b3c1e3d0eff971f13be6701292c77914b8794480f3391250',
+        'com.android:signflinger:4.1.1:signflinger-4.1.1.jar:0c66825988873ec2d51057fa463f54a8f18fc7326ff4530b9da363b71e97ce60',
+        'com.android:zipflinger:4.1.1:zipflinger-4.1.1.jar:0a8c3e52ac13dd031236f9fb5ba4408b1d5dcd12325a05440b36da09d8881446',
         'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
         'com.google.code.gson:gson:2.8.5:gson-2.8.5.jar:233a0149fc365c9f6edbd683cfe266b19bdc773be98eabdaf6b3c924b48e7d81',
         'com.google.dagger:dagger-compiler:2.24:dagger-compiler-2.24.jar:3c5afb955fb188da485cb2c048eff37dce0e1530b9780a0f2f7187d16d1ccc1f',
@@ -35,27 +38,30 @@ dependencyVerification {
         'com.google.dagger:dagger-spi:2.24:dagger-spi-2.24.jar:c038445d14dbcb4054e61bf49e05009edf26fce4fdc7ec1a9db544784f68e718',
         'com.google.dagger:dagger:2.24:dagger-2.24.jar:550a6e46a6dfcdf1d764887b6090cea94f783327e50e5c73754f18facfc70b64',
         'com.google.errorprone:error_prone_annotations:2.2.0:error_prone_annotations-2.2.0.jar:6ebd22ca1b9d8ec06d41de8d64e0596981d9607b42035f9ed374f9de271a481a',
+        'com.google.errorprone:error_prone_annotations:2.3.2:error_prone_annotations-2.3.2.jar:357cd6cfb067c969226c442451502aee13800a24e950fdfde77bcdb4565a668d',
         'com.google.errorprone:javac-shaded:9-dev-r4023-3:javac-shaded-9-dev-r4023-3.jar:65bfccf60986c47fbc17c9ebab0be626afc41741e0a6ec7109e0768817a36f30',
         'com.google.googlejavaformat:google-java-format:1.5:google-java-format-1.5.jar:aa19ad7850fb85178aa22f2fddb163b84d6ce4d0035872f30d4408195ca1144e',
         'com.google.guava:failureaccess:1.0.1:failureaccess-1.0.1.jar:a171ee4c734dd2da837e4b16be9df4661afab72a41adaf31eb84dfdaf936ca26',
-        'com.google.guava:guava:27.0.1-jre:guava-27.0.1-jre.jar:e1c814fd04492a27c38e0317eabeaa1b3e950ec8010239e400fe90ad6c9107b4',
         'com.google.guava:guava:27.1-jre:guava-27.1-jre.jar:4a5aa70cc968a4d137e599ad37553e5cfeed2265e8c193476d7119036c536fe7',
+        'com.google.guava:guava:28.1-jre:guava-28.1-jre.jar:30beb8b8527bd07c6e747e77f1a92122c2f29d57ce347461a4a55eb26e382da4',
         'com.google.guava:listenablefuture:9999.0-empty-to-avoid-conflict-with-guava:listenablefuture-9999.0-empty-to-avoid-conflict-with-guava.jar:b372a037d4230aa57fbeffdef30fd6123f9c0c2db85d0aced00c91b974f33f99',
         'com.google.j2objc:j2objc-annotations:1.1:j2objc-annotations-1.1.jar:2994a7eb78f2710bd3d3bfb639b2c94e219cedac0d4d084d516e78c16dddecf6',
+        'com.google.j2objc:j2objc-annotations:1.3:j2objc-annotations-1.3.jar:21af30c92267bd6122c0e0b4d20cccb6641a37eaf956c6540ec471d584e64a7b',
         'com.google.jimfs:jimfs:1.1:jimfs-1.1.jar:c4828e28d7c0a930af9387510b3bada7daa5c04d7c25a75c7b8b081f1c257ddd',
-        'com.google.protobuf:protobuf-java:3.4.0:protobuf-java-3.4.0.jar:dce7e66b32456a1b1198da0caff3a8acb71548658391e798c79369241e6490a4',
+        'com.google.protobuf:protobuf-java:3.10.0:protobuf-java-3.10.0.jar:161d7d61a8cb3970891c299578702fd079646e032329d6c2cabf998d191437c9',
         'com.googlecode.json-simple:json-simple:1.1:json-simple-1.1.jar:2d9484f4c649f708f47f9a479465fc729770ee65617dca3011836602264f6439',
         'com.squareup:javapoet:1.11.1:javapoet-1.11.1.jar:9cbf2107be499ec6e95afd36b58e3ca122a24166cdd375732e51267d64058e90',
         'com.squareup:javawriter:2.5.0:javawriter-2.5.0.jar:fcfb09fb0ea0aa97d3cfe7ea792398081348e468f126b3603cb3803f240197f0',
         'com.sun.activation:javax.activation:1.2.0:javax.activation-1.2.0.jar:993302b16cd7056f21e779cc577d175a810bb4900ef73cd8fbf2b50f928ba9ce',
-        'com.sun.istack:istack-commons-runtime:2.21:istack-commons-runtime-2.21.jar:c33e67a0807095f02a0e2da139412dd7c4f9cc1a4c054b3e434f96831ba950f4',
+        'com.sun.istack:istack-commons-runtime:3.0.7:istack-commons-runtime-3.0.7.jar:6443e10ba2e259fb821d9b6becf10db5316285fc30c53cec9d7b19a3877e7fdf',
-        'com.sun.xml.fastinfoset:FastInfoset:1.2.13:FastInfoset-1.2.13.jar:27a77db909f3c2833c0b1a37c55af1db06045118ad2eed96ce567b6632bce038',
+        'com.sun.xml.fastinfoset:FastInfoset:1.2.15:FastInfoset-1.2.15.jar:785861db11ca1bd0d1956682b974ad73eb19cd3e01a4b3fa82d62eca97210aec',
         'commons-codec:commons-codec:1.10:commons-codec-1.10.jar:4241dfa94e711d435f29a4604a3e2de5c4aa3c165e23bd066be6fc1fc4309569',
         'commons-logging:commons-logging:1.2:commons-logging-1.2.jar:daddea1ea0be0f56978ab3006b8ac92834afeefbd9b7e4e6316fca57df0fa636',
         'it.unimi.dsi:fastutil:7.2.0:fastutil-7.2.0.jar:74fa208043740642f7e6eb09faba15965218ad2f50ce3020efb100136e4b591c',
+        'javax.activation:javax.activation-api:1.2.0:javax.activation-api-1.2.0.jar:43fdef0b5b6ceb31b0424b208b930c74ab58fac2ceeb7b3f6fd3aeb8b5ca4393',
         'javax.annotation:jsr250-api:1.0:jsr250-api-1.0.jar:a1a922d0d9b6d183ed3800dfac01d1e1eb159f0e8c6f94736931c1def54a941f',
         'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
-        'javax.xml.bind:jaxb-api:2.2.12-b140109.1041:jaxb-api-2.2.12-b140109.1041.jar:b5e60cd8b7b5ff01ce4a74c5dd008f4fbd14ced3495d0b47b85cfedc182211f2',
+        'javax.xml.bind:jaxb-api:2.3.1:jaxb-api-2.3.1.jar:88b955a0df57880a26a74708bc34f74dcaf8ebf4e78843a28b50eae945732b06',
         'junit:junit:4.12:junit-4.12.jar:59721f0805e223d84b90677887d9ff567dc534d7c502ca903c0c2b17f05c116a',
         'net.ltgt.gradle.incap:incap:0.2:incap-0.2.jar:b625b9806b0f1e4bc7a2e3457119488de3cd57ea20feedd513db070a573a4ffd',
         'net.sf.jopt-simple:jopt-simple:4.9:jopt-simple-4.9.jar:26c5856e954b5f864db76f13b86919b59c6eecf9fd930b96baa8884626baf2f5',
@@ -70,34 +76,35 @@ dependencyVerification {
         'org.bouncycastle:bcpkix-jdk15on:1.56:bcpkix-jdk15on-1.56.jar:7043dee4e9e7175e93e0b36f45b1ec1ecb893c5f755667e8b916eb8dd201c6ca',
         'org.bouncycastle:bcprov-jdk15on:1.56:bcprov-jdk15on-1.56.jar:963e1ee14f808ffb99897d848ddcdb28fa91ddda867eb18d303e82728f878349',
         'org.briarproject:obfs4proxy-android:0.0.11-2:obfs4proxy-android-0.0.11-2.zip:57e55cbe87aa2aac210fdbb6cd8cdeafe15f825406a08ebf77a8b787aa2c6a8a',
-        'org.briarproject:tor-android:0.3.5.10:tor-android-0.3.5.10.zip:edd83bf557fcff2105eaa0bdb3f607a6852ebe7360920929ae3039dd5f4774c5',
+        'org.briarproject:tor-android:0.3.5.12:tor-android-0.3.5.12.zip:db71fb3290acff79d572af0752570eaf6aad7c4d88c9b9aa0b4d5afe2b9ead9c',
         'org.checkerframework:checker-compat-qual:2.5.3:checker-compat-qual-2.5.3.jar:d76b9afea61c7c082908023f0cbc1427fab9abd2df915c8b8a3e7a509bccbc6d',
         'org.checkerframework:checker-qual:2.5.2:checker-qual-2.5.2.jar:64b02691c8b9d4e7700f8ee2e742dce7ea2c6e81e662b7522c9ee3bf568c040a',
+        'org.checkerframework:checker-qual:2.8.1:checker-qual-2.8.1.jar:9103499008bcecd4e948da29b17864abb64304e15706444ae209d17ebe0575df',
         'org.codehaus.groovy:groovy-all:2.4.15:groovy-all-2.4.15.jar:51d6c4e71782e85674239189499854359d380fb75e1a703756e3aaa5b98a5af0',
         'org.codehaus.mojo:animal-sniffer-annotations:1.17:animal-sniffer-annotations-1.17.jar:92654f493ecfec52082e76354f0ebf87648dc3d5cec2e3c3cdb947c016747a53',
-        'org.glassfish.jaxb:jaxb-core:2.2.11:jaxb-core-2.2.11.jar:37bcaee8ebb04362c8352a5bf6221b86967ecdab5164c696b10b9a2bb587b2aa',
+        'org.codehaus.mojo:animal-sniffer-annotations:1.18:animal-sniffer-annotations-1.18.jar:47f05852b48ee9baefef80fa3d8cea60efa4753c0013121dd7fe5eef2e5c729d',
-        'org.glassfish.jaxb:jaxb-runtime:2.2.11:jaxb-runtime-2.2.11.jar:a874f2351cfba8e2946be3002d10c18a6da8f21b52ba2acf52f2b85d5520ed70',
+        'org.glassfish.jaxb:jaxb-runtime:2.3.1:jaxb-runtime-2.3.1.jar:45fecfa5c8217ce1f3652ab95179790ec8cc0dec0384bca51cbeb94a293d9f2f',
-        'org.glassfish.jaxb:txw2:2.2.11:txw2-2.2.11.jar:272a3ccad45a4511351920cd2a8633c53cab8d5220c7a92954da5526bb5eafea',
+        'org.glassfish.jaxb:txw2:2.3.1:txw2-2.3.1.jar:34975dde1c6920f1a39791142235689bc3cd357e24d05edd8ff93b885bd68d60',
         'org.hamcrest:hamcrest-core:1.3:hamcrest-core-1.3.jar:66fdef91e9739348df7a096aa384a5685f4e875584cce89386a7a47251c4d8e9',
         'org.hamcrest:hamcrest-library:1.3:hamcrest-library-1.3.jar:711d64522f9ec410983bd310934296da134be4254a125080a0416ec178dfad1c',
-        'org.jetbrains.kotlin:kotlin-reflect:1.3.50:kotlin-reflect-1.3.50.jar:64583199ea5a54aefd1bd1595288925f784226ee562d1dd279011c6075b3d7a4',
+        'org.jetbrains.kotlin:kotlin-reflect:1.3.72:kotlin-reflect-1.3.72.jar:a188d9367de1c4ee9479db630985c0597b20709c83161b1430d24edb27e38c40',
-        'org.jetbrains.kotlin:kotlin-stdlib-common:1.3.50:kotlin-stdlib-common-1.3.50.jar:8ce678e88e4ba018b66dacecf952471e4d7dfee156a8a819760a5a5ff29d323c',
+        'org.jetbrains.kotlin:kotlin-stdlib-common:1.3.72:kotlin-stdlib-common-1.3.72.jar:5e7d1552863e480c1628b1cc39ce230ef829f5b7230106215a05acda5172203a',
-        'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.3.50:kotlin-stdlib-jdk7-1.3.50.jar:9a026639e76212f8d57b86d55b075394c2e009f1979110751d34c05c5f75d57b',
+        'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.3.72:kotlin-stdlib-jdk7-1.3.72.jar:40566c0c08d414b9413ba556ff7f8a0b04b98b9f0f424d122dd2088510efccc4',
-        'org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.3.50:kotlin-stdlib-jdk8-1.3.50.jar:1b351fb6e09c14b55525c74c1f4cf48942eae43c348b7bc764a5e6e423d4da0c',
+        'org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.3.72:kotlin-stdlib-jdk8-1.3.72.jar:133da70cfc07b56094282eac5c59bccd59f167ee2ead22e5282876d8bc10bf95',
-        'org.jetbrains.kotlin:kotlin-stdlib:1.3.50:kotlin-stdlib-1.3.50.jar:e6f05746ee0366d0b52825a090fac474dcf44082c9083bbb205bd16976488d6c',
+        'org.jetbrains.kotlin:kotlin-stdlib:1.3.72:kotlin-stdlib-1.3.72.jar:3856a7349ebacd6d1be6802b2fed9c4dc2c5a564ea92b6b945ac988243d4b16b',
         'org.jetbrains.trove4j:trove4j:20160824:trove4j-20160824.jar:1917871c8deb468307a584680c87a44572f5a8b0b98c6d397fc0f5f86596dbe7',
         'org.jetbrains:annotations:13.0:annotations-13.0.jar:ace2a10dc8e2d5fd34925ecac03e4988b2c0f851650c94b8cef49ba1bd111478',
         'org.jmock:jmock-junit4:2.8.2:jmock-junit4-2.8.2.jar:f7ee4df4f7bd7b7f1cafad3b99eb74d579f109d5992ff625347352edb55e674c',
         'org.jmock:jmock-legacy:2.8.2:jmock-legacy-2.8.2.jar:f2b985a5c08a9edb7f37612330c058809da3f6a6d63ce792426ebf8ff0d6d31b',
         'org.jmock:jmock-testjar:2.8.2:jmock-testjar-2.8.2.jar:8900860f72c474e027cf97fe78dcbf154a1aa7fc62b6845c5fb4e4f3c7bc8760',
         'org.jmock:jmock:2.8.2:jmock-2.8.2.jar:6c73cb4a2e6dbfb61fd99c9a768539c170ab6568e57846bd60dbf19596b65b16',
-        'org.jvnet.staxex:stax-ex:1.7.7:stax-ex-1.7.7.jar:a31ff7d77163c0deb09e7fee59ad35ae44c2cee2cc8552a116ccd1583d813fb4',
+        'org.jvnet.staxex:stax-ex:1.8:stax-ex-1.8.jar:95b05d9590af4154c6513b9c5dc1fb2e55b539972ba0a9ef28e9a0c01d83ad77',
         'org.objenesis:objenesis:2.1:objenesis-2.1.jar:c74330cc6b806c804fd37e74487b4fe5d7c2750c5e15fbc6efa13bdee1bdef80',
-        'org.ow2.asm:asm-analysis:6.0:asm-analysis-6.0.jar:2f1a6387219c3a6cc4856481f221b03bd9f2408a326d416af09af5d6f608c1f4',
+        'org.ow2.asm:asm-analysis:7.0:asm-analysis-7.0.jar:e981f8f650c4d900bb033650b18e122fa6b161eadd5f88978d08751f72ee8474',
-        'org.ow2.asm:asm-commons:6.0:asm-commons-6.0.jar:f1bce5c648a96a017bdcd01fe5d59af9845297fd7b79b81c015a6fbbd9719abf',
+        'org.ow2.asm:asm-commons:7.0:asm-commons-7.0.jar:fed348ef05958e3e846a3ac074a12af5f7936ef3d21ce44a62c4fa08a771927d',
-        'org.ow2.asm:asm-tree:6.0:asm-tree-6.0.jar:887998fb69727c8759e4d253f856822801e33f9fd4caa566b3ac58ee92106215',
+        'org.ow2.asm:asm-tree:7.0:asm-tree-7.0.jar:cfd7a0874f9de36a999c127feeadfbfe6e04d4a71ee954d7af3d853f0be48a6c',
-        'org.ow2.asm:asm-util:6.0:asm-util-6.0.jar:356afebdb0f870175262e5188f8709a3b17aa2a5a6a4b0340b04d4b449bca5f6',
+        'org.ow2.asm:asm-util:7.0:asm-util-7.0.jar:75fbbca440ef463f41c2b0ab1a80abe67e910ac486da60a7863cbcb5bae7e145',
         'org.ow2.asm:asm:5.0.4:asm-5.0.4.jar:896618ed8ae62702521a78bc7be42b7c491a08e6920a15f89a3ecdec31e9a220',
-        'org.ow2.asm:asm:6.0:asm-6.0.jar:dd8971c74a4e697899a8e95caae4ea8760ea6c486dc6b97b1795e75760420461',
+        'org.ow2.asm:asm:7.0:asm-7.0.jar:b88ef66468b3c978ad0c97fd6e90979e56155b4ac69089ba7a44e9aa7ffe9acf',
     ]
 }

bramble-api/src/main/java/org/briarproject/bramble/api/io/TimeoutMonitor.java

@@ -7,6 +7,10 @@ public interface TimeoutMonitor {
 	/**
 	 * Returns an {@link InputStream} that wraps the given stream and allows
 	 * read timeouts to be detected.
+	 * <p>
+	 * The returned stream must be {@link InputStream#close() closed} when it's
+	 * no longer needed to ensure that resources held by the timeout monitor
+	 * are released.
 	 *
 	 * @param timeoutMs The read timeout in milliseconds. Timeouts will be
 	 * detected eventually but are not guaranteed to be detected immediately.

bramble-api/src/main/java/org/briarproject/bramble/api/lifecycle/LifecycleManager.java

@@ -5,6 +5,7 @@ import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.Wakeful;
 
 import java.util.concurrent.ExecutorService;
 
@@ -65,6 +66,7 @@ public interface LifecycleManager {
 	 * Opens the {@link DatabaseComponent} using the given key and starts any
 	 * registered {@link Service Services}.
 	 */
+	@Wakeful
 	StartResult startServices(SecretKey dbKey);
 
 	/**
@@ -72,6 +74,7 @@ public interface LifecycleManager {
 	 * registered {@link ExecutorService ExecutorServices}, and closes the
 	 * {@link DatabaseComponent}.
 	 */
+	@Wakeful
 	void stopServices();
 
 	/**
@@ -104,6 +107,7 @@ public interface LifecycleManager {
 		 *
 		 * @param txn A read-write transaction
 		 */
+		@Wakeful
 		void onDatabaseOpened(Transaction txn) throws DbException;
 	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/lifecycle/Service.java

@@ -1,16 +1,20 @@
 package org.briarproject.bramble.api.lifecycle;
 
+import org.briarproject.bramble.api.system.Wakeful;
+
 public interface Service {
 
 	/**
-	 * Starts the service.This method must not be called concurrently with
+	 * Starts the service. This method must not be called concurrently with
 	 * {@link #stopService()}.
 	 */
+	@Wakeful
 	void startService() throws ServiceException;
 
 	/**
 	 * Stops the service. This method must not be called concurrently with
 	 * {@link #startService()}.
 	 */
+	@Wakeful
 	void stopService() throws ServiceException;
 }

bramble-api/src/main/java/org/briarproject/bramble/api/network/NetworkStatus.java

@@ -8,11 +8,12 @@ import javax.annotation.concurrent.Immutable;
 @NotNullByDefault
 public class NetworkStatus {
 
-	private final boolean connected, wifi;
+	private final boolean connected, wifi, ipv6Only;
 
-	public NetworkStatus(boolean connected, boolean wifi) {
+	public NetworkStatus(boolean connected, boolean wifi, boolean ipv6Only) {
 		this.connected = connected;
 		this.wifi = wifi;
+		this.ipv6Only = ipv6Only;
 	}
 
 	public boolean isConnected() {
@@ -22,4 +23,8 @@ public class NetworkStatus {
 	public boolean isWifi() {
 		return wifi;
 	}
+
+	public boolean isIpv6Only() {
+		return ipv6Only;
+	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/BluetoothConstants.java

@@ -10,6 +10,12 @@ public interface BluetoothConstants {
 	String PROP_ADDRESS = "address";
 	String PROP_UUID = "uuid";
 
-	// Default value for PREF_PLUGIN_ENABLE
+	// Local settings (not shared with contacts)
+	String PREF_ADDRESS_IS_REFLECTED = "addressIsReflected";
+	String PREF_EVER_CONNECTED = "everConnected";
+
+	// Default values for local settings
 	boolean DEFAULT_PREF_PLUGIN_ENABLE = false;
+	boolean DEFAULT_PREF_ADDRESS_IS_REFLECTED = false;
+	boolean DEFAULT_PREF_EVER_CONNECTED = false;
 }

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/Plugin.java

@@ -4,6 +4,7 @@ import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.settings.SettingsManager;
+import org.briarproject.bramble.api.system.Wakeful;
 
 import java.util.Collection;
 
@@ -70,11 +71,13 @@ public interface Plugin {
 	/**
 	 * Starts the plugin.
 	 */
+	@Wakeful
 	void start() throws PluginException;
 
 	/**
 	 * Stops the plugin.
 	 */
+	@Wakeful
 	void stop() throws PluginException;
 
 	/**
@@ -106,6 +109,7 @@ public interface Plugin {
 	 * Attempts to create connections using the given transport properties,
 	 * passing any created connections to the corresponding handlers.
 	 */
+	@Wakeful
 	void poll(Collection<Pair<TransportProperties, ConnectionHandler>>
 			properties);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/PluginCallback.java

@@ -8,6 +8,8 @@ import org.briarproject.bramble.api.plugin.event.TransportStateEvent;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.settings.Settings;
 
+import java.util.Collection;
+
 /**
  * An interface through which a transport plugin interacts with the rest of
  * the application.
@@ -25,6 +27,11 @@ public interface PluginCallback extends ConnectionHandler {
 	 */
 	TransportProperties getLocalProperties();
 
+	/**
+	 * Returns the plugin's remote transport properties.
+	 */
+	Collection<TransportProperties> getRemoteProperties();
+
 	/**
 	 * Merges the given settings with the plugin's settings
 	 */

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/TorDirectory.java

@@ -1,5 +1,6 @@
-package org.briarproject.bramble.api.system;
+package org.briarproject.bramble.api.plugin;
 
+import java.io.File;
 import java.lang.annotation.Retention;
 import java.lang.annotation.Target;
 
@@ -11,15 +12,11 @@ import static java.lang.annotation.ElementType.PARAMETER;
 import static java.lang.annotation.RetentionPolicy.RUNTIME;
 
 /**
- * Annotation for injecting a scheduled executor service
+ * Annotation for injecting the {@link File directory} where the Tor plugin
- * that can be used to schedule the execution of tasks.
+ * should store its state.
- * <p>
- * The service should <b>only</b> be used for running tasks on other executors
- * at scheduled times.
- * No significant work should be run by the service itself!
  */
 @Qualifier
 @Target({FIELD, METHOD, PARAMETER})
 @Retention(RUNTIME)
-public @interface Scheduler {
+public @interface TorDirectory {
-}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/duplex/DuplexPlugin.java

@@ -8,6 +8,7 @@ import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.rendezvous.KeyMaterialSource;
 import org.briarproject.bramble.api.rendezvous.RendezvousEndpoint;
+import org.briarproject.bramble.api.system.Wakeful;
 
 import javax.annotation.Nullable;
 
@@ -21,6 +22,7 @@ public interface DuplexPlugin extends Plugin {
 	 * Attempts to create and return a connection using the given transport
 	 * properties. Returns null if a connection cannot be created.
 	 */
+	@Wakeful
 	@Nullable
 	DuplexTransportConnection createConnection(TransportProperties p);
 

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/event/BluetoothEnabledEvent.java

@@ -1,15 +0,0 @@
-package org.briarproject.bramble.api.plugin.event;
-
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * An event that informs the Bluetooth plugin that we have enabled the
- * Bluetooth adapter.
- */
-@Immutable
-@NotNullByDefault
-public class BluetoothEnabledEvent extends Event {
-}

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/event/DisableBluetoothEvent.java

@@ -1,15 +0,0 @@
-package org.briarproject.bramble.api.plugin.event;
-
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * An event that asks the Bluetooth plugin to disable the Bluetooth adapter if
- * we previously enabled it.
- */
-@Immutable
-@NotNullByDefault
-public class DisableBluetoothEvent extends Event {
-}

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/event/EnableBluetoothEvent.java

@@ -1,14 +0,0 @@
-package org.briarproject.bramble.api.plugin.event;
-
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * An event that asks the Bluetooth plugin to enable the Bluetooth adapter.
- */
-@Immutable
-@NotNullByDefault
-public class EnableBluetoothEvent extends Event {
-}

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/simplex/SimplexPlugin.java

@@ -5,6 +5,7 @@ import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.TransportConnectionReader;
 import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
 import org.briarproject.bramble.api.properties.TransportProperties;
+import org.briarproject.bramble.api.system.Wakeful;
 
 import javax.annotation.Nullable;
 
@@ -18,6 +19,7 @@ public interface SimplexPlugin extends Plugin {
 	 * Attempts to create and return a reader for the given transport
 	 * properties. Returns null if a reader cannot be created.
 	 */
+	@Wakeful
 	@Nullable
 	TransportConnectionReader createReader(TransportProperties p);
 
@@ -25,6 +27,7 @@ public interface SimplexPlugin extends Plugin {
 	 * Attempts to create and return a writer for the given transport
 	 * properties. Returns null if a writer cannot be created.
 	 */
+	@Wakeful
 	@Nullable
 	TransportConnectionWriter createWriter(TransportProperties p);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/properties/TransportPropertyConstants.java

@@ -12,6 +12,11 @@ public interface TransportPropertyConstants {
 	 */
 	int MAX_PROPERTY_LENGTH = 100;
 
+	/**
+	 * Prefix for keys that represent reflected properties.
+	 */
+	String REFLECTED_PROPERTY_PREFIX = "u:";
+
 	/**
 	 * Message metadata key for the transport ID of a local or remote update,
 	 * as a BDF string.

bramble-api/src/main/java/org/briarproject/bramble/api/properties/event/RemoteTransportPropertiesUpdatedEvent.java

@@ -0,0 +1,27 @@
+package org.briarproject.bramble.api.properties.event;
+
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.properties.TransportProperties;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that is broadcast when {@link TransportProperties} are received
+ * from a contact.
+ */
+@Immutable
+@NotNullByDefault
+public class RemoteTransportPropertiesUpdatedEvent extends Event {
+
+	private final TransportId transportId;
+
+	public RemoteTransportPropertiesUpdatedEvent(TransportId transportId) {
+		this.transportId = transportId;
+	}
+
+	public TransportId getTransportId() {
+		return transportId;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/reporting/DevReporter.java

@@ -23,6 +23,8 @@ public interface DevReporter {
 
 	/**
 	 * Sends any reports previously stored on disk.
+	 *
+	 * @return The number of reports that were sent.
 	 */
-	void sendReports();
+	int sendReports();
 }

bramble-api/src/main/java/org/briarproject/bramble/api/system/TaskScheduler.java

@@ -0,0 +1,43 @@
+package org.briarproject.bramble.api.system;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.util.concurrent.Executor;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * A service that can be used to schedule the execution of tasks.
+ */
+@NotNullByDefault
+public interface TaskScheduler {
+
+	/**
+	 * Submits the given task to the given executor after the given delay.
+	 * <p>
+	 * If the platform supports wake locks, a wake lock will be held while
+	 * submitting and running the task.
+	 */
+	Cancellable schedule(Runnable task, Executor executor, long delay,
+			TimeUnit unit);
+
+	/**
+	 * Submits the given task to the given executor after the given delay,
+	 * and then repeatedly with the given interval between executions
+	 * (measured from the end of one execution to the beginning of the next).
+	 * <p>
+	 * If the platform supports wake locks, a wake lock will be held while
+	 * submitting and running the task.
+	 */
+	Cancellable scheduleWithFixedDelay(Runnable task, Executor executor,
+			long delay, long interval, TimeUnit unit);
+
+	interface Cancellable {
+
+		/**
+		 * Cancels the task if it has not already started running. If the task
+		 * is {@link #scheduleWithFixedDelay(Runnable, Executor, long, long, TimeUnit) periodic},
+		 * all future executions of the task are cancelled.
+		 */
+		void cancel();
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/system/Wakeful.java

@@ -0,0 +1,19 @@
+package org.briarproject.bramble.api.system;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import javax.inject.Qualifier;
+
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+/**
+ * Annotation for methods that must be called while holding a wake lock, if
+ * the platform supports wake locks.
+ */
+@Qualifier
+@Target(METHOD)
+@Retention(RUNTIME)
+public @interface Wakeful {
+}

bramble-api/src/main/java/org/briarproject/bramble/api/system/WakefulIoExecutor.java

@@ -0,0 +1,26 @@
+package org.briarproject.bramble.api.system;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import javax.inject.Qualifier;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.PARAMETER;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+/**
+ * Annotation for injecting the executor for long-running IO tasks that should
+ * run without sleeping. Also used for annotating methods that should run on
+ * this executor.
+ * <p>
+ * The contract of this executor is that tasks may be run concurrently, and
+ * submitting a task will never block. Tasks must not run indefinitely. Tasks
+ * submitted during shutdown are discarded.
+ */
+@Qualifier
+@Target({FIELD, METHOD, PARAMETER})
+@Retention(RUNTIME)
+public @interface WakefulIoExecutor {
+}

bramble-core/src/main/java/org/briarproject/bramble/BrambleCoreEagerSingletons.java

@@ -9,7 +9,6 @@ import org.briarproject.bramble.plugin.PluginModule;
 import org.briarproject.bramble.properties.PropertiesModule;
 import org.briarproject.bramble.rendezvous.RendezvousModule;
 import org.briarproject.bramble.sync.validation.ValidationModule;
-import org.briarproject.bramble.system.SystemModule;
 import org.briarproject.bramble.transport.TransportModule;
 import org.briarproject.bramble.versioning.VersioningModule;
 
@@ -31,8 +30,6 @@ public interface BrambleCoreEagerSingletons {
 
 	void inject(RendezvousModule.EagerSingletons init);
 
-	void inject(SystemModule.EagerSingletons init);
-
 	void inject(TransportModule.EagerSingletons init);
 
 	void inject(ValidationModule.EagerSingletons init);
@@ -50,7 +47,6 @@ public interface BrambleCoreEagerSingletons {
 			c.inject(new RendezvousModule.EagerSingletons());
 			c.inject(new PluginModule.EagerSingletons());
 			c.inject(new PropertiesModule.EagerSingletons());
-			c.inject(new SystemModule.EagerSingletons());
 			c.inject(new TransportModule.EagerSingletons());
 			c.inject(new ValidationModule.EagerSingletons());
 			c.inject(new VersioningModule.EagerSingletons());

bramble-core/src/main/java/org/briarproject/bramble/BrambleCoreModule.java

@@ -21,7 +21,7 @@ import org.briarproject.bramble.rendezvous.RendezvousModule;
 import org.briarproject.bramble.settings.SettingsModule;
 import org.briarproject.bramble.sync.SyncModule;
 import org.briarproject.bramble.sync.validation.ValidationModule;
-import org.briarproject.bramble.system.SystemModule;
+import org.briarproject.bramble.system.ClockModule;
 import org.briarproject.bramble.transport.TransportModule;
 import org.briarproject.bramble.versioning.VersioningModule;
 
@@ -29,6 +29,7 @@ import dagger.Module;
 
 @Module(includes = {
 		ClientModule.class,
+		ClockModule.class,
 		ConnectionModule.class,
 		ContactModule.class,
 		CryptoModule.class,
@@ -48,7 +49,6 @@ import dagger.Module;
 		RendezvousModule.class,
 		SettingsModule.class,
 		SyncModule.class,
-		SystemModule.class,
 		TransportModule.class,
 		ValidationModule.class,
 		VersioningModule.class

bramble-core/src/main/java/org/briarproject/bramble/contact/PendingContactFactoryImpl.java

@@ -11,6 +11,7 @@ import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.util.Base32;
 
 import java.security.GeneralSecurityException;
+import java.util.Locale;
 import java.util.regex.Matcher;
 
 import javax.inject.Inject;
@@ -52,7 +53,7 @@ class PendingContactFactoryImpl implements PendingContactFactory {
 		byte[] raw = new byte[RAW_LINK_BYTES];
 		raw[0] = FORMAT_VERSION;
 		arraycopy(encoded, 0, raw, 1, encoded.length);
-		return "briar://" + Base32.encode(raw).toLowerCase();
+		return "briar://" + Base32.encode(raw).toLowerCase(Locale.US);
 	}
 
 	private PublicKey parseHandshakeLink(String link) throws FormatException {

bramble-core/src/main/java/org/briarproject/bramble/io/TimeoutMonitorImpl.java

@@ -3,15 +3,15 @@ package org.briarproject.bramble.io;
 import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.api.system.Scheduler;
+import org.briarproject.bramble.api.system.TaskScheduler;
+import org.briarproject.bramble.api.system.TaskScheduler.Cancellable;
+import org.briarproject.bramble.api.system.Wakeful;
 
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.Executor;
-import java.util.concurrent.Future;
-import java.util.concurrent.ScheduledExecutorService;
 import java.util.logging.Logger;
 
 import javax.annotation.concurrent.GuardedBy;
@@ -30,7 +30,7 @@ class TimeoutMonitorImpl implements TimeoutMonitor {
 
 	private static final long CHECK_INTERVAL_MS = SECONDS.toMillis(10);
 
-	private final ScheduledExecutorService scheduler;
+	private final TaskScheduler scheduler;
 	private final Executor ioExecutor;
 	private final Clock clock;
 	private final Object lock = new Object();
@@ -38,10 +38,10 @@ class TimeoutMonitorImpl implements TimeoutMonitor {
 	private final List<TimeoutInputStream> streams = new ArrayList<>();
 
 	@GuardedBy("lock")
-	private Future<?> task = null;
+	private Cancellable cancellable = null;
 
 	@Inject
-	TimeoutMonitorImpl(@Scheduler ScheduledExecutorService scheduler,
+	TimeoutMonitorImpl(TaskScheduler scheduler,
 			@IoExecutor Executor ioExecutor, Clock clock) {
 		this.scheduler = scheduler;
 		this.ioExecutor = ioExecutor;
@@ -55,8 +55,9 @@ class TimeoutMonitorImpl implements TimeoutMonitor {
 				timeoutMs, this::removeStream);
 		synchronized (lock) {
 			if (streams.isEmpty()) {
-				task = scheduler.scheduleWithFixedDelay(this::checkTimeouts,
+				cancellable = scheduler.scheduleWithFixedDelay(
-						CHECK_INTERVAL_MS, CHECK_INTERVAL_MS, MILLISECONDS);
+						this::checkTimeouts, ioExecutor, CHECK_INTERVAL_MS,
+						CHECK_INTERVAL_MS, MILLISECONDS);
 			}
 			streams.add(stream);
 		}
@@ -64,33 +65,35 @@ class TimeoutMonitorImpl implements TimeoutMonitor {
 	}
 
 	private void removeStream(TimeoutInputStream stream) {
-		Future<?> toCancel = null;
+		Cancellable toCancel = null;
 		synchronized (lock) {
 			if (streams.remove(stream) && streams.isEmpty()) {
-				toCancel = task;
+				toCancel = cancellable;
-				task = null;
+				cancellable = null;
 			}
 		}
-		if (toCancel != null) toCancel.cancel(false);
+		if (toCancel != null) {
+			LOG.info("Cancelling timeout monitor task");
+			toCancel.cancel();
+		}
 	}
 
-	@Scheduler
+	@IoExecutor
+	@Wakeful
 	private void checkTimeouts() {
-		ioExecutor.execute(() -> {
+		List<TimeoutInputStream> snapshot;
-			List<TimeoutInputStream> snapshot;
+		synchronized (lock) {
-			synchronized (lock) {
+			snapshot = new ArrayList<>(streams);
-				snapshot = new ArrayList<>(streams);
+		}
-			}
+		for (TimeoutInputStream stream : snapshot) {
-			for (TimeoutInputStream stream : snapshot) {
+			if (stream.hasTimedOut()) {
-				if (stream.hasTimedOut()) {
+				LOG.info("Input stream has timed out");
-					LOG.info("Input stream has timed out");
+				try {
-					try {
+					stream.close();
-						stream.close();
+				} catch (IOException e) {
-					} catch (IOException e) {
+					logException(LOG, INFO, e);
-						logException(LOG, INFO, e);
-					}
 				}
 			}
-		});
+		}
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/KeyAgreementConnector.java

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.keyagreement;
 
+import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.crypto.KeyAgreementCrypto;
 import org.briarproject.bramble.api.crypto.KeyPair;
 import org.briarproject.bramble.api.data.BdfList;
@@ -8,6 +9,8 @@ import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
 import org.briarproject.bramble.api.keyagreement.Payload;
 import org.briarproject.bramble.api.keyagreement.TransportDescriptor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.BluetoothConstants;
+import org.briarproject.bramble.api.plugin.LanTcpConstants;
 import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.PluginManager;
 import org.briarproject.bramble.api.plugin.TransportId;
@@ -19,7 +22,9 @@ import org.briarproject.bramble.api.record.RecordWriterFactory;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.concurrent.Callable;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.CountDownLatch;
@@ -28,8 +33,10 @@ import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 
+import static java.util.Arrays.asList;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.CONNECTION_TIMEOUT;
 import static org.briarproject.bramble.util.LogUtils.logException;
 
@@ -41,7 +48,10 @@ class KeyAgreementConnector {
 	}
 
 	private static final Logger LOG =
-			Logger.getLogger(KeyAgreementConnector.class.getName());
+			getLogger(KeyAgreementConnector.class.getName());
+
+	private static final List<TransportId> PREFERRED_TRANSPORTS =
+			asList(BluetoothConstants.ID, LanTcpConstants.ID);
 
 	private final Callbacks callbacks;
 	private final KeyAgreementCrypto keyAgreementCrypto;
@@ -105,24 +115,35 @@ class KeyAgreementConnector {
 		this.alice = alice;
 		aliceLatch.countDown();
 
-		// Start connecting over supported transports
+		// Start connecting over supported transports in order of preference
 		if (LOG.isLoggable(INFO)) {
 			LOG.info("Starting outgoing BQP connections as "
 					+ (alice ? "Alice" : "Bob"));
 		}
+		Map<TransportId, TransportDescriptor> descriptors = new HashMap<>();
 		for (TransportDescriptor d : remotePayload.getTransportDescriptors()) {
-			Plugin p = pluginManager.getPlugin(d.getId());
+			descriptors.put(d.getId(), d);
-			if (p instanceof DuplexPlugin) {
+		}
+		List<Pair<DuplexPlugin, BdfList>> transports = new ArrayList<>();
+		for (TransportId id : PREFERRED_TRANSPORTS) {
+			TransportDescriptor d = descriptors.get(id);
+			Plugin p = pluginManager.getPlugin(id);
+			if (d != null && p instanceof DuplexPlugin) {
 				if (LOG.isLoggable(INFO))
-					LOG.info("Connecting via " + d.getId());
+					LOG.info("Connecting via " + id);
-				DuplexPlugin plugin = (DuplexPlugin) p;
+				transports.add(new Pair<>((DuplexPlugin) p, d.getDescriptor()));
-				byte[] commitment = remotePayload.getCommitment();
-				BdfList descriptor = d.getDescriptor();
-				connectionChooser.submit(new ReadableTask(
-						new ConnectorTask(plugin, commitment, descriptor)));
 			}
 		}
 
+		// TODO: If we don't have any transports in common with the peer,
+		//  warn the user and give up (#1224)
+
+		if (!transports.isEmpty()) {
+			byte[] commitment = remotePayload.getCommitment();
+			connectionChooser.submit(new ReadableTask(new ConnectorTask(
+					transports, commitment)));
+		}
+
 		// Get chosen connection
 		try {
 			KeyAgreementConnection chosen =
@@ -148,15 +169,13 @@ class KeyAgreementConnector {
 
 	private class ConnectorTask implements Callable<KeyAgreementConnection> {
 
+		private final List<Pair<DuplexPlugin, BdfList>> transports;
 		private final byte[] commitment;
-		private final BdfList descriptor;
-		private final DuplexPlugin plugin;
 
-		private ConnectorTask(DuplexPlugin plugin, byte[] commitment,
+		private ConnectorTask(List<Pair<DuplexPlugin, BdfList>> transports,
-				BdfList descriptor) {
+				byte[] commitment) {
-			this.plugin = plugin;
+			this.transports = transports;
 			this.commitment = commitment;
-			this.descriptor = descriptor;
 		}
 
 		@Nullable
@@ -164,13 +183,18 @@ class KeyAgreementConnector {
 		public KeyAgreementConnection call() throws Exception {
 			// Repeat attempts until we connect, get stopped, or get interrupted
 			while (!stopped) {
-				DuplexTransportConnection conn =
+				for (Pair<DuplexPlugin, BdfList> pair : transports) {
-						plugin.createKeyAgreementConnection(commitment,
+					if (stopped) return null;
-								descriptor);
+					DuplexPlugin plugin = pair.getFirst();
-				if (conn != null) {
+					BdfList descriptor = pair.getSecond();
-					if (LOG.isLoggable(INFO))
+					DuplexTransportConnection conn =
-						LOG.info(plugin.getId() + ": Outgoing connection");
+							plugin.createKeyAgreementConnection(commitment,
-					return new KeyAgreementConnection(conn, plugin.getId());
+									descriptor);
+					if (conn != null) {
+						if (LOG.isLoggable(INFO))
+							LOG.info(plugin.getId() + ": Outgoing connection");
+						return new KeyAgreementConnection(conn, plugin.getId());
+					}
 				}
 				// Wait 2s before retry (to circumvent transient failures)
 				Thread.sleep(2000);

bramble-core/src/main/java/org/briarproject/bramble/plugin/PluginManagerImpl.java

@@ -1,6 +1,7 @@
 package org.briarproject.bramble.plugin;
 
 import org.briarproject.bramble.api.connection.ConnectionManager;
+import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
@@ -28,6 +29,7 @@ import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
 import org.briarproject.bramble.api.settings.Settings;
 import org.briarproject.bramble.api.settings.SettingsManager;
+import org.briarproject.bramble.api.system.WakefulIoExecutor;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -44,12 +46,14 @@ import java.util.logging.Logger;
 import javax.annotation.concurrent.ThreadSafe;
 import javax.inject.Inject;
 
+import static java.util.Collections.emptyList;
 import static java.util.logging.Level.FINE;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.plugin.Plugin.PREF_PLUGIN_ENABLE;
 import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
+import static org.briarproject.bramble.api.plugin.Plugin.State.DISABLED;
 import static org.briarproject.bramble.api.plugin.Plugin.State.STARTING_STOPPING;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.logException;
@@ -62,7 +66,7 @@ class PluginManagerImpl implements PluginManager, Service {
 	private static final Logger LOG =
 			getLogger(PluginManagerImpl.class.getName());
 
-	private final Executor ioExecutor;
+	private final Executor ioExecutor, wakefulIoExecutor;
 	private final EventBus eventBus;
 	private final PluginConfig pluginConfig;
 	private final ConnectionManager connectionManager;
@@ -75,11 +79,15 @@ class PluginManagerImpl implements PluginManager, Service {
 	private final AtomicBoolean used = new AtomicBoolean(false);
 
 	@Inject
-	PluginManagerImpl(@IoExecutor Executor ioExecutor, EventBus eventBus,
+	PluginManagerImpl(@IoExecutor Executor ioExecutor,
-			PluginConfig pluginConfig, ConnectionManager connectionManager,
+			@WakefulIoExecutor Executor wakefulIoExecutor,
+			EventBus eventBus,
+			PluginConfig pluginConfig,
+			ConnectionManager connectionManager,
 			SettingsManager settingsManager,
 			TransportPropertyManager transportPropertyManager) {
 		this.ioExecutor = ioExecutor;
+		this.wakefulIoExecutor = wakefulIoExecutor;
 		this.eventBus = eventBus;
 		this.pluginConfig = pluginConfig;
 		this.connectionManager = connectionManager;
@@ -107,7 +115,7 @@ class PluginManagerImpl implements PluginManager, Service {
 				simplexPlugins.add(s);
 				CountDownLatch startLatch = new CountDownLatch(1);
 				startLatches.put(t, startLatch);
-				ioExecutor.execute(new PluginStarter(s, startLatch));
+				wakefulIoExecutor.execute(new PluginStarter(s, startLatch));
 			}
 		}
 		// Instantiate the duplex plugins and start them asynchronously
@@ -123,7 +131,7 @@ class PluginManagerImpl implements PluginManager, Service {
 				duplexPlugins.add(d);
 				CountDownLatch startLatch = new CountDownLatch(1);
 				startLatches.put(t, startLatch);
-				ioExecutor.execute(new PluginStarter(d, startLatch));
+				wakefulIoExecutor.execute(new PluginStarter(d, startLatch));
 			}
 		}
 	}
@@ -135,12 +143,16 @@ class PluginManagerImpl implements PluginManager, Service {
 		LOG.info("Stopping simplex plugins");
 		for (SimplexPlugin s : simplexPlugins) {
 			CountDownLatch startLatch = startLatches.get(s.getId());
+			// Don't need the wakeful executor here as we wait for the plugin
+			// to stop before returning
 			ioExecutor.execute(new PluginStopper(s, startLatch, stopLatch));
 		}
 		// Stop the duplex plugins
 		LOG.info("Stopping duplex plugins");
 		for (DuplexPlugin d : duplexPlugins) {
 			CountDownLatch startLatch = startLatches.get(d.getId());
+			// Don't need the wakeful executor here as we wait for the plugin
+			// to stop before returning
 			ioExecutor.execute(new PluginStopper(d, startLatch, stopLatch));
 		}
 		// Wait for all the plugins to stop
@@ -203,7 +215,7 @@ class PluginManagerImpl implements PluginManager, Service {
 		}
 	}
 
-	private class PluginStarter implements Runnable {
+	private static class PluginStarter implements Runnable {
 
 		private final Plugin plugin;
 		private final CountDownLatch startLatch;
@@ -233,7 +245,7 @@ class PluginManagerImpl implements PluginManager, Service {
 		}
 	}
 
-	private class PluginStopper implements Runnable {
+	private static class PluginStopper implements Runnable {
 
 		private final Plugin plugin;
 		private final CountDownLatch startLatch, stopLatch;
@@ -303,6 +315,18 @@ class PluginManagerImpl implements PluginManager, Service {
 			}
 		}
 
+		@Override
+		public Collection<TransportProperties> getRemoteProperties() {
+			try {
+				Map<ContactId, TransportProperties> remote =
+						transportPropertyManager.getRemoteProperties(id);
+				return remote.values();
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+				return emptyList();
+			}
+		}
+
 		@Override
 		public void mergeSettings(Settings s) {
 			PluginManagerImpl.this.mergeSettings(s, id.getString());
@@ -331,6 +355,10 @@ class PluginManagerImpl implements PluginManager, Service {
 				} else if (oldState == ACTIVE) {
 					eventBus.broadcast(new TransportInactiveEvent(id));
 				}
+			} else if (newState == DISABLED) {
+				// Broadcast an event even though the state hasn't changed, as
+				// the reasons for the plugin being disabled may have changed
+				eventBus.broadcast(new TransportStateEvent(id, newState));
 			}
 		}
 

bramble-core/src/main/java/org/briarproject/bramble/plugin/PollerImpl.java

@@ -26,7 +26,10 @@ import org.briarproject.bramble.api.plugin.simplex.SimplexPlugin;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
 import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.api.system.Scheduler;
+import org.briarproject.bramble.api.system.TaskScheduler;
+import org.briarproject.bramble.api.system.TaskScheduler.Cancellable;
+import org.briarproject.bramble.api.system.Wakeful;
+import org.briarproject.bramble.api.system.WakefulIoExecutor;
 
 import java.security.SecureRandom;
 import java.util.ArrayList;
@@ -35,8 +38,6 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.concurrent.Executor;
-import java.util.concurrent.Future;
-import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.logging.Logger;
@@ -57,8 +58,8 @@ class PollerImpl implements Poller, EventListener {
 
 	private static final Logger LOG = getLogger(PollerImpl.class.getName());
 
-	private final Executor ioExecutor;
+	private final Executor ioExecutor, wakefulIoExecutor;
-	private final ScheduledExecutorService scheduler;
+	private final TaskScheduler scheduler;
 	private final ConnectionManager connectionManager;
 	private final ConnectionRegistry connectionRegistry;
 	private final PluginManager pluginManager;
@@ -71,12 +72,16 @@ class PollerImpl implements Poller, EventListener {
 
 	@Inject
 	PollerImpl(@IoExecutor Executor ioExecutor,
-			@Scheduler ScheduledExecutorService scheduler,
+			@WakefulIoExecutor Executor wakefulIoExecutor,
+			TaskScheduler scheduler,
 			ConnectionManager connectionManager,
-			ConnectionRegistry connectionRegistry, PluginManager pluginManager,
+			ConnectionRegistry connectionRegistry,
+			PluginManager pluginManager,
 			TransportPropertyManager transportPropertyManager,
-			SecureRandom random, Clock clock) {
+			SecureRandom random,
+			Clock clock) {
 		this.ioExecutor = ioExecutor;
+		this.wakefulIoExecutor = wakefulIoExecutor;
 		this.scheduler = scheduler;
 		this.connectionManager = connectionManager;
 		this.connectionRegistry = connectionRegistry;
@@ -133,7 +138,7 @@ class PollerImpl implements Poller, EventListener {
 	}
 
 	private void connectToContact(ContactId c, SimplexPlugin p) {
-		ioExecutor.execute(() -> {
+		wakefulIoExecutor.execute(() -> {
 			TransportId t = p.getId();
 			if (connectionRegistry.isConnected(c, t)) return;
 			try {
@@ -149,7 +154,7 @@ class PollerImpl implements Poller, EventListener {
 	}
 
 	private void connectToContact(ContactId c, DuplexPlugin p) {
-		ioExecutor.execute(() -> {
+		wakefulIoExecutor.execute(() -> {
 			TransportId t = p.getId();
 			if (connectionRegistry.isConnected(c, t)) return;
 			try {
@@ -186,11 +191,11 @@ class PollerImpl implements Poller, EventListener {
 			if (scheduled == null || due < scheduled.task.due) {
 				// If a later task exists, cancel it. If it's already started
 				// it will abort safely when it finds it's been replaced
-				if (scheduled != null) scheduled.future.cancel(false);
+				if (scheduled != null) scheduled.cancellable.cancel();
 				PollTask task = new PollTask(p, due, randomiseNext);
-				Future future = scheduler.schedule(() ->
+				Cancellable cancellable = scheduler.schedule(task, ioExecutor,
-						ioExecutor.execute(task), delay, MILLISECONDS);
+						delay, MILLISECONDS);
-				tasks.put(t, new ScheduledPollTask(task, future));
+				tasks.put(t, new ScheduledPollTask(task, cancellable));
 			}
 		} finally {
 			lock.unlock();
@@ -201,7 +206,7 @@ class PollerImpl implements Poller, EventListener {
 		lock.lock();
 		try {
 			ScheduledPollTask scheduled = tasks.remove(t);
-			if (scheduled != null) scheduled.future.cancel(false);
+			if (scheduled != null) scheduled.cancellable.cancel();
 		} finally {
 			lock.unlock();
 		}
@@ -232,11 +237,11 @@ class PollerImpl implements Poller, EventListener {
 	private class ScheduledPollTask {
 
 		private final PollTask task;
-		private final Future future;
+		private final Cancellable cancellable;
 
-		private ScheduledPollTask(PollTask task, Future future) {
+		private ScheduledPollTask(PollTask task, Cancellable cancellable) {
 			this.task = task;
-			this.future = future;
+			this.cancellable = cancellable;
 		}
 	}
 
@@ -254,6 +259,7 @@ class PollerImpl implements Poller, EventListener {
 
 		@Override
 		@IoExecutor
+		@Wakeful
 		public void run() {
 			lock.lock();
 			try {

bramble-core/src/main/java/org/briarproject/bramble/plugin/bluetooth/BluetoothConnectionFactory.java

@@ -0,0 +1,14 @@
+package org.briarproject.bramble.plugin.bluetooth;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
+import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
+
+import java.io.IOException;
+
+@NotNullByDefault
+interface BluetoothConnectionFactory<S> {
+
+	DuplexTransportConnection wrapSocket(DuplexPlugin plugin, S socket)
+			throws IOException;
+}

bramble-core/src/main/java/org/briarproject/bramble/plugin/bluetooth/BluetoothPlugin.java

@@ -1,11 +1,11 @@
 package org.briarproject.bramble.plugin.bluetooth;
 
 import org.briarproject.bramble.api.FormatException;
+import org.briarproject.bramble.api.Multiset;
 import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventListener;
-import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementConnection;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
 import org.briarproject.bramble.api.keyagreement.event.KeyAgreementListeningEvent;
@@ -21,10 +21,8 @@ import org.briarproject.bramble.api.plugin.PluginException;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.plugin.event.BluetoothEnabledEvent;
-import org.briarproject.bramble.api.plugin.event.DisableBluetoothEvent;
-import org.briarproject.bramble.api.plugin.event.EnableBluetoothEvent;
 import org.briarproject.bramble.api.properties.TransportProperties;
+import org.briarproject.bramble.api.properties.event.RemoteTransportPropertiesUpdatedEvent;
 import org.briarproject.bramble.api.rendezvous.KeyMaterialSource;
 import org.briarproject.bramble.api.rendezvous.RendezvousEndpoint;
 import org.briarproject.bramble.api.settings.Settings;
@@ -46,8 +44,12 @@ import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.TRANSPORT_ID_BLUETOOTH;
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.DEFAULT_PREF_ADDRESS_IS_REFLECTED;
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.DEFAULT_PREF_EVER_CONNECTED;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.DEFAULT_PREF_PLUGIN_ENABLE;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.PREF_ADDRESS_IS_REFLECTED;
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.PREF_EVER_CONNECTED;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_ADDRESS;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_UUID;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.UUID_BYTES;
@@ -55,6 +57,7 @@ import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
 import static org.briarproject.bramble.api.plugin.Plugin.State.DISABLED;
 import static org.briarproject.bramble.api.plugin.Plugin.State.INACTIVE;
 import static org.briarproject.bramble.api.plugin.Plugin.State.STARTING_STOPPING;
+import static org.briarproject.bramble.api.properties.TransportPropertyConstants.REFLECTED_PROPERTY_PREFIX;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.PrivacyUtils.scrubMacAddress;
 import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
@@ -63,20 +66,21 @@ import static org.briarproject.bramble.util.StringUtils.macToString;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
+abstract class BluetoothPlugin<S, SS> implements DuplexPlugin, EventListener {
 
 	private static final Logger LOG =
 			getLogger(BluetoothPlugin.class.getName());
 
 	final BluetoothConnectionLimiter connectionLimiter;
-	final TimeoutMonitor timeoutMonitor;
+	final BluetoothConnectionFactory<S> connectionFactory;
 
-	private final Executor ioExecutor;
+	private final Executor ioExecutor, wakefulIoExecutor;
 	private final SecureRandom secureRandom;
 	private final Backoff backoff;
 	private final PluginCallback callback;
 	private final int maxLatency, maxIdleTime;
 	private final AtomicBoolean used = new AtomicBoolean(false);
+	private final AtomicBoolean everConnected = new AtomicBoolean(false);
 
 	protected final PluginState state = new PluginState();
 
@@ -86,12 +90,6 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 
 	abstract boolean isAdapterEnabled();
 
-	abstract void enableAdapter();
-
-	abstract void disableAdapterIfEnabledByUs();
-
-	abstract void setEnabledByUs();
-
 	/**
 	 * Returns the local Bluetooth address, or null if no valid address can
 	 * be found.
@@ -115,12 +113,18 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 	abstract DuplexTransportConnection discoverAndConnect(String uuid);
 
 	BluetoothPlugin(BluetoothConnectionLimiter connectionLimiter,
-			TimeoutMonitor timeoutMonitor, Executor ioExecutor,
+			BluetoothConnectionFactory<S> connectionFactory,
-			SecureRandom secureRandom, Backoff backoff,
+			Executor ioExecutor,
-			PluginCallback callback, int maxLatency, int maxIdleTime) {
+			Executor wakefulIoExecutor,
+			SecureRandom secureRandom,
+			Backoff backoff,
+			PluginCallback callback,
+			int maxLatency,
+			int maxIdleTime) {
 		this.connectionLimiter = connectionLimiter;
-		this.timeoutMonitor = timeoutMonitor;
+		this.connectionFactory = connectionFactory;
 		this.ioExecutor = ioExecutor;
+		this.wakefulIoExecutor = wakefulIoExecutor;
 		this.secureRandom = secureRandom;
 		this.backoff = backoff;
 		this.callback = callback;
@@ -167,6 +171,8 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		Settings settings = callback.getSettings();
 		boolean enabledByUser = settings.getBoolean(PREF_PLUGIN_ENABLE,
 				DEFAULT_PREF_PLUGIN_ENABLE);
+		everConnected.set(settings.getBoolean(PREF_EVER_CONNECTED,
+				DEFAULT_PREF_EVER_CONNECTED));
 		state.setStarted(enabledByUser);
 		try {
 			initialiseAdapter();
@@ -174,10 +180,7 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 			throw new PluginException(e);
 		}
 		updateProperties();
-		if (enabledByUser) {
+		if (enabledByUser && isAdapterEnabled()) bind();
-			if (isAdapterEnabled()) bind();
-			else enableAdapter();
-		}
 	}
 
 	private void bind() {
@@ -205,25 +208,68 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		TransportProperties p = callback.getLocalProperties();
 		String address = p.get(PROP_ADDRESS);
 		String uuid = p.get(PROP_UUID);
+		Settings s = callback.getSettings();
+		boolean isReflected = s.getBoolean(PREF_ADDRESS_IS_REFLECTED,
+				DEFAULT_PREF_ADDRESS_IS_REFLECTED);
 		boolean changed = false;
-		if (address == null) {
+		if (address == null || isReflected) {
 			address = getBluetoothAddress();
-			if (LOG.isLoggable(INFO))
+			if (LOG.isLoggable(INFO)) {
 				LOG.info("Local address " + scrubMacAddress(address));
-			if (!isNullOrEmpty(address)) {
+			}
-				p.put(PROP_ADDRESS, address);
+			if (address == null) {
+				if (everConnected.get()) {
+					address = getReflectedAddress();
+					if (LOG.isLoggable(INFO)) {
+						LOG.info("Reflected address " +
+								scrubMacAddress(address));
+					}
+					if (address != null) {
+						changed = true;
+						isReflected = true;
+					}
+				}
+			} else {
 				changed = true;
+				isReflected = false;
 			}
 		}
 		if (uuid == null) {
 			byte[] random = new byte[UUID_BYTES];
 			secureRandom.nextBytes(random);
 			uuid = UUID.nameUUIDFromBytes(random).toString();
-			p.put(PROP_UUID, uuid);
 			changed = true;
 		}
 		contactConnectionsUuid = uuid;
-		if (changed) callback.mergeLocalProperties(p);
+		if (changed) {
+			p = new TransportProperties();
+			// If we previously used a reflected address and there's no longer
+			// a reflected address with enough votes to be used, we'll continue
+			// to use the old reflected address until there's a new winner
+			if (address != null) p.put(PROP_ADDRESS, address);
+			p.put(PROP_UUID, uuid);
+			callback.mergeLocalProperties(p);
+			s = new Settings();
+			s.putBoolean(PREF_ADDRESS_IS_REFLECTED, isReflected);
+			callback.mergeSettings(s);
+		}
+	}
+
+	@Nullable
+	private String getReflectedAddress() {
+		// Count the number of votes for each reflected address
+		String key = REFLECTED_PROPERTY_PREFIX + PROP_ADDRESS;
+		Multiset<String> votes = new Multiset<>();
+		for (TransportProperties p : callback.getRemoteProperties()) {
+			String address = p.get(key);
+			if (address != null && isValidAddress(address)) votes.add(address);
+		}
+		// If an address gets more than half of the votes, accept it
+		int total = votes.getTotal();
+		for (String address : votes.keySet()) {
+			if (votes.getCount(address) * 2 > total) return address;
+		}
+		return null;
 	}
 
 	private void acceptContactConnections(SS ss) {
@@ -240,15 +286,27 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 			LOG.info("Connection received");
 			connectionLimiter.connectionOpened(conn);
 			backoff.reset();
+			setEverConnected();
 			callback.handleConnection(conn);
 		}
 	}
 
+	private void setEverConnected() {
+		if (!everConnected.getAndSet(true)) {
+			ioExecutor.execute(() -> {
+				Settings s = new Settings();
+				s.putBoolean(PREF_EVER_CONNECTED, true);
+				callback.mergeSettings(s);
+				// Contacts may already have sent a reflected address
+				updateProperties();
+			});
+		}
+	}
+
 	@Override
 	public void stop() {
 		SS ss = state.setStopped();
 		tryToClose(ss);
-		disableAdapterIfEnabledByUs();
 	}
 
 	@Override
@@ -286,10 +344,11 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		if (isNullOrEmpty(address)) return;
 		String uuid = p.get(PROP_UUID);
 		if (isNullOrEmpty(uuid)) return;
-		ioExecutor.execute(() -> {
+		wakefulIoExecutor.execute(() -> {
 			DuplexTransportConnection d = createConnection(p);
 			if (d != null) {
 				backoff.reset();
+				setEverConnected();
 				h.handleConnection(d);
 			}
 		});
@@ -377,8 +436,10 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		String uuid = UUID.nameUUIDFromBytes(commitment).toString();
 		DuplexTransportConnection conn;
 		if (descriptor.size() == 1) {
-			if (LOG.isLoggable(INFO))
+			if (LOG.isLoggable(INFO)) {
-				LOG.info("Discovering address for key agreement UUID " + uuid);
+				LOG.info("Discovering address for key agreement UUID " +
+						uuid);
+			}
 			conn = discoverAndConnect(uuid);
 		} else {
 			String address;
@@ -392,7 +453,10 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 				LOG.info("Connecting to key agreement UUID " + uuid);
 			conn = connect(address, uuid);
 		}
-		if (conn != null) connectionLimiter.connectionOpened(conn);
+		if (conn != null) {
+			connectionLimiter.connectionOpened(conn);
+			setEverConnected();
+		}
 		return conn;
 	}
 
@@ -415,13 +479,7 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 
 	@Override
 	public void eventOccurred(Event e) {
-		if (e instanceof EnableBluetoothEvent) {
+		if (e instanceof SettingsUpdatedEvent) {
-			ioExecutor.execute(this::enableAdapter);
-		} else if (e instanceof DisableBluetoothEvent) {
-			ioExecutor.execute(this::disableAdapterIfEnabledByUs);
-		} else if (e instanceof BluetoothEnabledEvent) {
-			setEnabledByUs();
-		} else if (e instanceof SettingsUpdatedEvent) {
 			SettingsUpdatedEvent s = (SettingsUpdatedEvent) e;
 			if (s.getNamespace().equals(ID.getString()))
 				ioExecutor.execute(() -> onSettingsUpdated(s.getSettings()));
@@ -429,6 +487,12 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 			ioExecutor.execute(connectionLimiter::keyAgreementStarted);
 		} else if (e instanceof KeyAgreementStoppedListeningEvent) {
 			ioExecutor.execute(connectionLimiter::keyAgreementEnded);
+		} else if (e instanceof RemoteTransportPropertiesUpdatedEvent) {
+			RemoteTransportPropertiesUpdatedEvent r =
+					(RemoteTransportPropertiesUpdatedEvent) e;
+			if (r.getTransportId().equals(ID)) {
+				ioExecutor.execute(this::updateProperties);
+			}
 		}
 	}
 
@@ -441,11 +505,13 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		if (ss != null) {
 			LOG.info("Disabled by user, closing server socket");
 			tryToClose(ss);
-			disableAdapterIfEnabledByUs();
 		} else if (s == INACTIVE) {
-			LOG.info("Enabled by user, opening server socket");
+			if (isAdapterEnabled()) {
-			if (isAdapterEnabled()) bind();
+				LOG.info("Enabled by user, opening server socket");
-			else enableAdapter();
+				bind();
+			} else {
+				LOG.info("Enabled by user but adapter is disabled");
+			}
 		}
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/LanTcpPlugin.java

@@ -88,10 +88,15 @@ class LanTcpPlugin extends TcpPlugin {
 		}
 	}
 
-	LanTcpPlugin(Executor ioExecutor, Backoff backoff, PluginCallback callback,
+	LanTcpPlugin(Executor ioExecutor,
-			int maxLatency, int maxIdleTime, int connectionTimeout) {
+			Executor wakefulIoExecutor,
-		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime,
+			Backoff backoff,
-				connectionTimeout);
+			PluginCallback callback,
+			int maxLatency,
+			int maxIdleTime,
+			int connectionTimeout) {
+		super(ioExecutor, wakefulIoExecutor, backoff, callback, maxLatency,
+				maxIdleTime, connectionTimeout);
 	}
 
 	@Override
@@ -349,7 +354,7 @@ class LanTcpPlugin extends TcpPlugin {
 				tryToClose(ss, LOG, WARNING);
 			}
 		}
-		if (ss == null) {
+		if (ss == null || !ss.isBound()) {
 			LOG.info("Could not bind server socket for key agreement");
 			return null;
 		}

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/LanTcpPluginFactory.java

@@ -1,6 +1,7 @@
 package org.briarproject.bramble.plugin.tcp;
 
 import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.BackoffFactory;
@@ -8,10 +9,12 @@ import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
+import org.briarproject.bramble.api.system.WakefulIoExecutor;
 
 import java.util.concurrent.Executor;
 
 import javax.annotation.concurrent.Immutable;
+import javax.inject.Inject;
 
 import static org.briarproject.bramble.api.plugin.LanTcpConstants.ID;
 
@@ -26,13 +29,17 @@ public class LanTcpPluginFactory implements DuplexPluginFactory {
 	private static final int MAX_POLLING_INTERVAL = 600_000; // 10 mins
 	private static final double BACKOFF_BASE = 1.2;
 
-	private final Executor ioExecutor;
+	private final Executor ioExecutor, wakefulIoExecutor;
 	private final EventBus eventBus;
 	private final BackoffFactory backoffFactory;
 
-	public LanTcpPluginFactory(Executor ioExecutor, EventBus eventBus,
+	@Inject
+	public LanTcpPluginFactory(@IoExecutor Executor ioExecutor,
+			@WakefulIoExecutor Executor wakefulIoExecutor,
+			EventBus eventBus,
 			BackoffFactory backoffFactory) {
 		this.ioExecutor = ioExecutor;
+		this.wakefulIoExecutor = wakefulIoExecutor;
 		this.eventBus = eventBus;
 		this.backoffFactory = backoffFactory;
 	}
@@ -51,8 +58,9 @@ public class LanTcpPluginFactory implements DuplexPluginFactory {
 	public DuplexPlugin createPlugin(PluginCallback callback) {
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
-		LanTcpPlugin plugin =  new LanTcpPlugin(ioExecutor, backoff, callback, MAX_LATENCY,
+		LanTcpPlugin plugin = new LanTcpPlugin(ioExecutor, wakefulIoExecutor,
-				MAX_IDLE_TIME, CONNECTION_TIMEOUT);
+				backoff, callback, MAX_LATENCY, MAX_IDLE_TIME,
+				CONNECTION_TIMEOUT);
 		eventBus.addListener(plugin);
 		return plugin;
 	}

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/TcpPlugin.java

@@ -66,7 +66,7 @@ abstract class TcpPlugin implements DuplexPlugin, EventListener {
 	private static final Pattern DOTTED_QUAD =
 			Pattern.compile("^\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}$");
 
-	protected final Executor ioExecutor, bindExecutor;
+	protected final Executor ioExecutor, wakefulIoExecutor, bindExecutor;
 	protected final Backoff backoff;
 	protected final PluginCallback callback;
 	protected final int maxLatency, maxIdleTime;
@@ -107,9 +107,15 @@ abstract class TcpPlugin implements DuplexPlugin, EventListener {
 	 */
 	protected abstract boolean isEnabledByDefault();
 
-	TcpPlugin(Executor ioExecutor, Backoff backoff, PluginCallback callback,
+	TcpPlugin(Executor ioExecutor,
-			int maxLatency, int maxIdleTime, int connectionTimeout) {
+			Executor wakefulIoExecutor,
+			Backoff backoff,
+			PluginCallback callback,
+			int maxLatency,
+			int maxIdleTime,
+			int connectionTimeout) {
 		this.ioExecutor = ioExecutor;
+		this.wakefulIoExecutor = wakefulIoExecutor;
 		this.backoff = backoff;
 		this.callback = callback;
 		this.maxLatency = maxLatency;
@@ -143,15 +149,21 @@ abstract class TcpPlugin implements DuplexPlugin, EventListener {
 
 	protected void bind() {
 		bindExecutor.execute(() -> {
-			if (getState() != INACTIVE) return;
+			State s = getState();
+			if (s != ACTIVE && s != INACTIVE) return;
 			bind(true);
 			bind(false);
 		});
 	}
 
 	private void bind(boolean ipv4) {
+		ServerSocket old = state.getServerSocket(ipv4);
 		ServerSocket ss = null;
 		for (InetSocketAddress addr : getLocalSocketAddresses(ipv4)) {
+			if (old != null && addr.equals(old.getLocalSocketAddress())) {
+				LOG.info("Server socket already bound");
+				return;
+			}
 			try {
 				ss = new ServerSocket();
 				ss.bind(addr);
@@ -162,7 +174,7 @@ abstract class TcpPlugin implements DuplexPlugin, EventListener {
 				tryToClose(ss, LOG, WARNING);
 			}
 		}
-		if (ss == null) {
+		if (ss == null || !ss.isBound()) {
 			LOG.info("Could not bind server socket");
 			return;
 		}
@@ -245,7 +257,7 @@ abstract class TcpPlugin implements DuplexPlugin, EventListener {
 	}
 
 	private void connect(TransportProperties p, ConnectionHandler h) {
-		ioExecutor.execute(() -> {
+		wakefulIoExecutor.execute(() -> {
 			DuplexTransportConnection d = createConnection(p);
 			if (d != null) {
 				backoff.reset();

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/WanTcpPlugin.java

@@ -30,11 +30,16 @@ class WanTcpPlugin extends TcpPlugin {
 
 	private volatile MappingResult mappingResult;
 
-	WanTcpPlugin(Executor ioExecutor, Backoff backoff, PortMapper portMapper,
+	WanTcpPlugin(Executor ioExecutor,
-			PluginCallback callback, int maxLatency, int maxIdleTime,
+			Executor wakefulIoExecutor,
+			Backoff backoff,
+			PortMapper portMapper,
+			PluginCallback callback,
+			int maxLatency,
+			int maxIdleTime,
 			int connectionTimeout) {
-		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime,
+		super(ioExecutor, wakefulIoExecutor, backoff, callback, maxLatency,
-				connectionTimeout);
+				maxIdleTime, connectionTimeout);
 		this.portMapper = portMapper;
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/WanTcpPluginFactory.java

@@ -1,6 +1,7 @@
 package org.briarproject.bramble.plugin.tcp;
 
 import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.lifecycle.ShutdownManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
@@ -9,10 +10,12 @@ import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
+import org.briarproject.bramble.api.system.WakefulIoExecutor;
 
 import java.util.concurrent.Executor;
 
 import javax.annotation.concurrent.Immutable;
+import javax.inject.Inject;
 
 import static org.briarproject.bramble.api.plugin.WanTcpConstants.ID;
 
@@ -27,14 +30,19 @@ public class WanTcpPluginFactory implements DuplexPluginFactory {
 	private static final int MAX_POLLING_INTERVAL = 600_000; // 10 mins
 	private static final double BACKOFF_BASE = 1.2;
 
-	private final Executor ioExecutor;
+	private final Executor ioExecutor, wakefulIoExecutor;
 	private final EventBus eventBus;
 	private final BackoffFactory backoffFactory;
 	private final ShutdownManager shutdownManager;
 
-	public WanTcpPluginFactory(Executor ioExecutor, EventBus eventBus,
+	@Inject
-			BackoffFactory backoffFactory, ShutdownManager shutdownManager) {
+	public WanTcpPluginFactory(@IoExecutor Executor ioExecutor,
+			@WakefulIoExecutor Executor wakefulIoExecutor,
+			EventBus eventBus,
+			BackoffFactory backoffFactory,
+			ShutdownManager shutdownManager) {
 		this.ioExecutor = ioExecutor;
+		this.wakefulIoExecutor = wakefulIoExecutor;
 		this.eventBus = eventBus;
 		this.backoffFactory = backoffFactory;
 		this.shutdownManager = shutdownManager;
@@ -54,9 +62,10 @@ public class WanTcpPluginFactory implements DuplexPluginFactory {
 	public DuplexPlugin createPlugin(PluginCallback callback) {
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
-		WanTcpPlugin plugin = new WanTcpPlugin(ioExecutor, backoff,
+		PortMapper portMapper = new PortMapperImpl(shutdownManager);
-				new PortMapperImpl(shutdownManager), callback, MAX_LATENCY,
+		WanTcpPlugin plugin = new WanTcpPlugin(ioExecutor, wakefulIoExecutor,
-				MAX_IDLE_TIME, CONNECTION_TIMEOUT);
+				backoff, portMapper, callback, MAX_LATENCY, MAX_IDLE_TIME,
+				CONNECTION_TIMEOUT);
 		eventBus.addListener(plugin);
 		return plugin;
 	}

bramble-core/src/main/java/org/briarproject/bramble/plugin/tor/TorPlugin.java

@@ -118,7 +118,8 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	private static final Pattern ONION_V2 = Pattern.compile("[a-z2-7]{16}");
 	private static final Pattern ONION_V3 = Pattern.compile("[a-z2-7]{56}");
 
-	private final Executor ioExecutor, connectionStatusExecutor;
+	private final Executor ioExecutor, wakefulIoExecutor;
+	private final Executor connectionStatusExecutor;
 	private final NetworkManager networkManager;
 	private final LocationUtils locationUtils;
 	private final SocketFactory torSocketFactory;
@@ -131,7 +132,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	private final CircumventionProvider circumventionProvider;
 	private final ResourceProvider resourceProvider;
 	private final int maxLatency, maxIdleTime, socketTimeout;
-	private final File torDirectory, torFile, geoIpFile, obfs4File, configFile;
+	private final File torDirectory, geoIpFile, configFile;
 	private final File doneFile, cookieFile;
 	private final AtomicBoolean used = new AtomicBoolean(false);
 
@@ -145,15 +146,24 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 
 	protected abstract long getLastUpdateTime();
 
-	TorPlugin(Executor ioExecutor, NetworkManager networkManager,
+	TorPlugin(Executor ioExecutor,
-			LocationUtils locationUtils, SocketFactory torSocketFactory,
+			Executor wakefulIoExecutor,
-			Clock clock, ResourceProvider resourceProvider,
+			NetworkManager networkManager,
+			LocationUtils locationUtils,
+			SocketFactory torSocketFactory,
+			Clock clock,
+			ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
-			BatteryManager batteryManager, Backoff backoff,
+			BatteryManager batteryManager,
+			Backoff backoff,
 			TorRendezvousCrypto torRendezvousCrypto,
-			PluginCallback callback, String architecture, int maxLatency,
+			PluginCallback callback,
-			int maxIdleTime, File torDirectory) {
+			String architecture,
+			int maxLatency,
+			int maxIdleTime,
+			File torDirectory) {
 		this.ioExecutor = ioExecutor;
+		this.wakefulIoExecutor = wakefulIoExecutor;
 		this.networkManager = networkManager;
 		this.locationUtils = locationUtils;
 		this.torSocketFactory = torSocketFactory;
@@ -171,9 +181,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			socketTimeout = Integer.MAX_VALUE;
 		else socketTimeout = maxIdleTime * 2;
 		this.torDirectory = torDirectory;
-		torFile = new File(torDirectory, "tor");
 		geoIpFile = new File(torDirectory, "geoip");
-		obfs4File = new File(torDirectory, "obfs4proxy");
 		configFile = new File(torDirectory, "torrc");
 		doneFile = new File(torDirectory, "done");
 		cookieFile = new File(torDirectory, ".tor/control_auth_cookie");
@@ -182,6 +190,14 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 				new PoliteExecutor("TorPlugin", ioExecutor, 1);
 	}
 
+	protected File getTorExecutableFile() {
+		return new File(torDirectory, "tor");
+	}
+
+	protected File getObfs4ExecutableFile() {
+		return new File(torDirectory, "obfs4proxy");
+	}
+
 	@Override
 	public TransportId getId() {
 		return TorConstants.ID;
@@ -214,6 +230,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			LOG.warning("Old auth cookie not deleted");
 		// Start a new Tor process
 		LOG.info("Starting Tor");
+		File torFile = getTorExecutableFile();
 		String torPath = torFile.getAbsolutePath();
 		String configPath = configFile.getAbsolutePath();
 		String pid = String.valueOf(getProcessId());
@@ -312,44 +329,43 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}
 
 	private void installAssets() throws PluginException {
-		InputStream in = null;
-		OutputStream out = null;
 		try {
 			// The done file may already exist from a previous installation
 			//noinspection ResultOfMethodCallIgnored
 			doneFile.delete();
-			// Unzip the Tor binary to the filesystem
+			installTorExecutable();
-			in = getTorInputStream();
+			installObfs4Executable();
-			out = new FileOutputStream(torFile);
+			extract(getGeoIpInputStream(), geoIpFile);
-			copyAndClose(in, out);
+			extract(getConfigInputStream(), configFile);
-			// Make the Tor binary executable
-			if (!torFile.setExecutable(true, true)) throw new IOException();
-			// Unzip the GeoIP database to the filesystem
-			in = getGeoIpInputStream();
-			out = new FileOutputStream(geoIpFile);
-			copyAndClose(in, out);
-			// Unzip the Obfs4 proxy to the filesystem
-			in = getObfs4InputStream();
-			out = new FileOutputStream(obfs4File);
-			copyAndClose(in, out);
-			// Make the Obfs4 proxy executable
-			if (!obfs4File.setExecutable(true, true)) throw new IOException();
-			// Copy the config file to the filesystem
-			in = getConfigInputStream();
-			out = new FileOutputStream(configFile);
-			copyAndClose(in, out);
 			if (!doneFile.createNewFile())
 				LOG.warning("Failed to create done file");
 		} catch (IOException e) {
-			tryToClose(in, LOG, WARNING);
-			tryToClose(out, LOG, WARNING);
 			throw new PluginException(e);
 		}
 	}
 
-	private InputStream getTorInputStream() throws IOException {
+	protected void extract(InputStream in, File dest) throws IOException {
+		OutputStream out = new FileOutputStream(dest);
+		copyAndClose(in, out);
+	}
+
+	protected void installTorExecutable() throws IOException {
 		if (LOG.isLoggable(INFO))
 			LOG.info("Installing Tor binary for " + architecture);
+		File torFile = getTorExecutableFile();
+		extract(getTorInputStream(), torFile);
+		if (!torFile.setExecutable(true, true)) throw new IOException();
+	}
+
+	protected void installObfs4Executable() throws IOException {
+		if (LOG.isLoggable(INFO))
+			LOG.info("Installing obfs4proxy binary for " + architecture);
+		File obfs4File = getObfs4ExecutableFile();
+		extract(getObfs4InputStream(), obfs4File);
+		if (!obfs4File.setExecutable(true, true)) throw new IOException();
+	}
+
+	private InputStream getTorInputStream() throws IOException {
 		InputStream in = resourceProvider
 				.getResourceInputStream("tor_" + architecture, ".zip");
 		ZipInputStream zin = new ZipInputStream(in);
@@ -366,8 +382,6 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}
 
 	private InputStream getObfs4InputStream() throws IOException {
-		if (LOG.isLoggable(INFO))
-			LOG.info("Installing obfs4proxy binary for " + architecture);
 		InputStream in = resourceProvider
 				.getResourceInputStream("obfs4proxy_" + architecture, ".zip");
 		ZipInputStream zin = new ZipInputStream(in);
@@ -452,7 +466,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		// in the migration period since first publishing it
 		if (!isNullOrEmpty(privKey2)) {
 			long now = clock.currentTimeMillis();
-			long then = v3Created == null ? now : Long.valueOf(v3Created);
+			long then = v3Created == null ? now : Long.parseLong(v3Created);
 			if (now - then >= V3_MIGRATION_PERIOD_MS) retireV2HiddenService();
 			else publishV2HiddenService(port, privKey2);
 		}
@@ -514,15 +528,15 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			LOG.warning("Tor did not return a private key");
 			return;
 		}
-		// Publish the hidden service's onion hostname in transport properties
 		String onion3 = response.get(HS_ADDRESS);
 		if (LOG.isLoggable(INFO)) {
 			LOG.info("V3 hidden service " + scrubOnion(onion3));
 		}
-		TransportProperties p = new TransportProperties();
-		p.put(PROP_ONION_V3, onion3);
-		callback.mergeLocalProperties(p);
 		if (privKey == null) {
+			// Publish the hidden service's onion hostname in transport props
+			TransportProperties p = new TransportProperties();
+			p.put(PROP_ONION_V3, onion3);
+			callback.mergeLocalProperties(p);
 			// Save the hidden service's private key for next time
 			Settings s = new Settings();
 			s.put(HS_PRIVATE_KEY_V3, response.get(HS_PRIVKEY));
@@ -559,6 +573,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		if (enable) {
 			Collection<String> conf = new ArrayList<>();
 			conf.add("UseBridges 1");
+			File obfs4File = getObfs4ExecutableFile();
 			if (needsMeek) {
 				conf.add("ClientTransportPlugin meek_lite exec " +
 						obfs4File.getAbsolutePath());
@@ -620,7 +635,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}
 
 	private void connect(TransportProperties p, ConnectionHandler h) {
-		ioExecutor.execute(() -> {
+		wakefulIoExecutor.execute(() -> {
 			DuplexTransportConnection d = createConnection(p);
 			if (d != null) {
 				backoff.reset();
@@ -848,6 +863,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			if (!state.isTorRunning()) return;
 			boolean online = status.isConnected();
 			boolean wifi = status.isWifi();
+			boolean ipv6Only = status.isIpv6Only();
 			String country = locationUtils.getCurrentCountry();
 			boolean blocked =
 					circumventionProvider.isTorProbablyBlocked(country);
@@ -864,7 +880,8 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			boolean automatic = network == PREF_TOR_NETWORK_AUTOMATIC;
 
 			if (LOG.isLoggable(INFO)) {
-				LOG.info("Online: " + online + ", wifi: " + wifi);
+				LOG.info("Online: " + online + ", wifi: " + wifi
+						+ ", IPv6 only: " + ipv6Only);
 				if (country.isEmpty()) LOG.info("Country code unknown");
 				else LOG.info("Country code: " + country);
 				LOG.info("Charging: " + charging);
@@ -901,7 +918,8 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 					enableNetwork = true;
 					if (network == PREF_TOR_NETWORK_WITH_BRIDGES ||
 							(automatic && bridgesWork)) {
-						if (circumventionProvider.needsMeek(country)) {
+						if (ipv6Only ||
+								circumventionProvider.needsMeek(country)) {
 							LOG.info("Using meek bridges");
 							enableBridges = true;
 							useMeek = true;
@@ -927,6 +945,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 				if (enableNetwork) {
 					enableBridges(enableBridges, useMeek);
 					enableConnectionPadding(enableConnectionPadding);
+					useIpv6(ipv6Only);
 				}
 				enableNetwork(enableNetwork);
 			} catch (IOException e) {
@@ -939,6 +958,11 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		controlConnection.setConf("ConnectionPadding", enable ? "1" : "0");
 	}
 
+	private void useIpv6(boolean ipv6Only) throws IOException {
+		controlConnection.setConf("ClientUseIPv4", ipv6Only ? "0" : "1");
+		controlConnection.setConf("ClientUseIPv6", ipv6Only ? "1" : "0");
+	}
+
 	@ThreadSafe
 	@NotNullByDefault
 	protected class PluginState {

bramble-core/src/main/java/org/briarproject/bramble/properties/TransportPropertyManagerImpl.java

@@ -18,6 +18,7 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
+import org.briarproject.bramble.api.properties.event.RemoteTransportPropertiesUpdatedEvent;
 import org.briarproject.bramble.api.sync.Group;
 import org.briarproject.bramble.api.sync.Group.Visibility;
 import org.briarproject.bramble.api.sync.GroupId;
@@ -42,6 +43,7 @@ import static org.briarproject.bramble.api.properties.TransportPropertyConstants
 import static org.briarproject.bramble.api.properties.TransportPropertyConstants.MSG_KEY_LOCAL;
 import static org.briarproject.bramble.api.properties.TransportPropertyConstants.MSG_KEY_TRANSPORT_ID;
 import static org.briarproject.bramble.api.properties.TransportPropertyConstants.MSG_KEY_VERSION;
+import static org.briarproject.bramble.api.properties.TransportPropertyConstants.REFLECTED_PROPERTY_PREFIX;
 import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
 
 @Immutable
@@ -129,8 +131,10 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 					// We've already received a newer update - delete this one
 					db.deleteMessage(txn, m.getId());
 					db.deleteMessageMetadata(txn, m.getId());
+					return false;
 				}
 			}
+			txn.attach(new RemoteTransportPropertiesUpdatedEvent(t));
 		} catch (FormatException e) {
 			throw new InvalidMessageException(e);
 		}
@@ -153,15 +157,27 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 		if (props.isEmpty()) return;
 		try {
 			db.transaction(false, txn -> {
-				Group g = getContactGroup(db.getContact(txn, c));
+				Contact contact = db.getContact(txn, c);
+				Group g = getContactGroup(contact);
 				BdfDictionary meta = clientHelper.getGroupMetadataAsDictionary(
 						txn, g.getId());
 				BdfDictionary discovered =
 						meta.getOptionalDictionary(GROUP_KEY_DISCOVERED);
-				if (discovered == null) discovered = new BdfDictionary();
+				BdfDictionary merged;
-				discovered.putAll(props);
+				boolean changed;
-				meta.put(GROUP_KEY_DISCOVERED, discovered);
+				if (discovered == null) {
-				clientHelper.mergeGroupMetadata(txn, g.getId(), meta);
+					merged = new BdfDictionary(props);
+					changed = true;
+				} else {
+					merged = new BdfDictionary(discovered);
+					merged.putAll(props);
+					changed = !merged.equals(discovered);
+				}
+				if (changed) {
+					meta.put(GROUP_KEY_DISCOVERED, merged);
+					clientHelper.mergeGroupMetadata(txn, g.getId(), meta);
+					updateLocalProperties(txn, contact, t);
+				}
 			});
 		} catch (FormatException e) {
 			throw new DbException(e);
@@ -226,6 +242,24 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 		});
 	}
 
+	private void updateLocalProperties(Transaction txn, Contact c,
+			TransportId t) throws DbException {
+		try {
+			TransportProperties local;
+			LatestUpdate latest = findLatest(txn, localGroup.getId(), t, true);
+			if (latest == null) {
+				local = new TransportProperties();
+			} else {
+				BdfList message = clientHelper.getMessageAsList(txn,
+						latest.messageId);
+				local = parseProperties(message);
+			}
+			storeLocalProperties(txn, c, t, local);
+		} catch (FormatException e) {
+			throw new DbException(e);
+		}
+	}
+
 	private TransportProperties getRemoteProperties(Transaction txn, Contact c,
 			TransportId t) throws DbException {
 		Group g = getContactGroup(c);
@@ -298,18 +332,10 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 					storeMessage(txn, localGroup.getId(), t, merged, version,
 							true, false);
 					// Delete the previous update, if any
-					if (latest != null)
+					if (latest != null) db.removeMessage(txn, latest.messageId);
-						db.removeMessage(txn, latest.messageId);
 					// Store the merged properties in each contact's group
 					for (Contact c : db.getContacts(txn)) {
-						Group g = getContactGroup(c);
+						storeLocalProperties(txn, c, t, merged);
-						latest = findLatest(txn, g.getId(), t, true);
-						version = latest == null ? 1 : latest.version + 1;
-						storeMessage(txn, g.getId(), t, merged, version,
-								true, true);
-						// Delete the previous update, if any
-						if (latest != null)
-							db.removeMessage(txn, latest.messageId);
 					}
 				}
 			});
@@ -318,6 +344,34 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 		}
 	}
 
+	private void storeLocalProperties(Transaction txn, Contact c,
+			TransportId t, TransportProperties p)
+			throws DbException, FormatException {
+		Group g = getContactGroup(c);
+		LatestUpdate latest = findLatest(txn, g.getId(), t, true);
+		long version = latest == null ? 1 : latest.version + 1;
+		// Reflect any remote properties we've discovered
+		BdfDictionary meta = clientHelper.getGroupMetadataAsDictionary(txn,
+				g.getId());
+		BdfDictionary discovered =
+				meta.getOptionalDictionary(GROUP_KEY_DISCOVERED);
+		TransportProperties combined;
+		if (discovered == null) {
+			combined = p;
+		} else {
+			combined = new TransportProperties(p);
+			TransportProperties d = clientHelper
+					.parseAndValidateTransportProperties(discovered);
+			for (Entry<String, String> e : d.entrySet()) {
+				String key = REFLECTED_PROPERTY_PREFIX + e.getKey();
+				combined.put(key, e.getValue());
+			}
+		}
+		storeMessage(txn, g.getId(), t, combined, version, true, true);
+		// Delete the previous update, if any
+		if (latest != null) db.removeMessage(txn, latest.messageId);
+	}
+
 	private Group getContactGroup(Contact c) {
 		return contactGroupFactory.createContactGroup(CLIENT_ID,
 				MAJOR_VERSION, c);

bramble-core/src/main/java/org/briarproject/bramble/rendezvous/RendezvousPollerImpl.java

@@ -41,7 +41,9 @@ import org.briarproject.bramble.api.rendezvous.event.RendezvousConnectionClosedE
 import org.briarproject.bramble.api.rendezvous.event.RendezvousConnectionOpenedEvent;
 import org.briarproject.bramble.api.rendezvous.event.RendezvousPollEvent;
 import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.api.system.Scheduler;
+import org.briarproject.bramble.api.system.TaskScheduler;
+import org.briarproject.bramble.api.system.TaskScheduler.Cancellable;
+import org.briarproject.bramble.api.system.Wakeful;
 
 import java.security.GeneralSecurityException;
 import java.util.ArrayList;
@@ -52,7 +54,6 @@ import java.util.Map;
 import java.util.Map.Entry;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Logger;
 
@@ -68,6 +69,7 @@ import static org.briarproject.bramble.api.contact.PendingContactState.ADDING_CO
 import static org.briarproject.bramble.api.contact.PendingContactState.FAILED;
 import static org.briarproject.bramble.api.contact.PendingContactState.OFFLINE;
 import static org.briarproject.bramble.api.contact.PendingContactState.WAITING_FOR_CONNECTION;
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
 import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNull;
 import static org.briarproject.bramble.rendezvous.RendezvousConstants.POLLING_INTERVAL_MS;
 import static org.briarproject.bramble.rendezvous.RendezvousConstants.RENDEZVOUS_TIMEOUT_MS;
@@ -80,7 +82,7 @@ class RendezvousPollerImpl implements RendezvousPoller, Service, EventListener {
 	private static final Logger LOG =
 			getLogger(RendezvousPollerImpl.class.getName());
 
-	private final ScheduledExecutorService scheduler;
+	private final TaskScheduler scheduler;
 	private final DatabaseComponent db;
 	private final IdentityManager identityManager;
 	private final TransportCrypto transportCrypto;
@@ -102,10 +104,12 @@ class RendezvousPollerImpl implements RendezvousPoller, Service, EventListener {
 			new HashMap<>();
 	@Nullable
 	private KeyPair handshakeKeyPair = null;
+	@Nullable
+	private Cancellable pollTask = null;
 
 	@Inject
 	RendezvousPollerImpl(@IoExecutor Executor ioExecutor,
-			@Scheduler ScheduledExecutorService scheduler,
+			TaskScheduler scheduler,
 			DatabaseComponent db,
 			IdentityManager identityManager,
 			TransportCrypto transportCrypto,
@@ -144,8 +148,6 @@ class RendezvousPollerImpl implements RendezvousPoller, Service, EventListener {
 		} catch (DbException e) {
 			throw new ServiceException(e);
 		}
-		scheduler.scheduleAtFixedRate(this::poll, POLLING_INTERVAL_MS,
-				POLLING_INTERVAL_MS, MILLISECONDS);
 	}
 
 	@EventExecutor
@@ -186,6 +188,12 @@ class RendezvousPollerImpl implements RendezvousPoller, Service, EventListener {
 			}
 			if (cs.numEndpoints == 0) broadcastState(p.getId(), OFFLINE);
 			else broadcastState(p.getId(), WAITING_FOR_CONNECTION);
+			if (cryptoStates.size() == 1) {
+				LOG.info("Starting poller");
+				requireNull(pollTask);
+				pollTask = scheduler.scheduleWithFixedDelay(this::poll, worker,
+						POLLING_INTERVAL_MS, POLLING_INTERVAL_MS, MILLISECONDS);
+			}
 		} catch (DbException | GeneralSecurityException e) {
 			logException(LOG, WARNING, e);
 		}
@@ -205,12 +213,12 @@ class RendezvousPollerImpl implements RendezvousPoller, Service, EventListener {
 		return plugin.createRendezvousEndpoint(k, cs.alice, h);
 	}
 
-	@Scheduler
+	// Worker
+	@Wakeful
 	private void poll() {
-		worker.execute(() -> {
+		LOG.info("Polling");
-			removeExpiredPendingContacts();
+		removeExpiredPendingContacts();
-			for (PluginState ps : pluginStates.values()) poll(ps);
+		for (PluginState ps : pluginStates.values()) poll(ps);
-		});
 	}
 
 	// Worker
@@ -235,9 +243,15 @@ class RendezvousPollerImpl implements RendezvousPoller, Service, EventListener {
 			RendezvousEndpoint endpoint = ps.endpoints.remove(p);
 			if (endpoint != null) tryToClose(endpoint, LOG, INFO);
 		}
+		if (cryptoStates.isEmpty()) {
+			LOG.info("Stopping poller");
+			requireNonNull(pollTask).cancel();
+			pollTask = null;
+		}
 	}
 
 	// Worker
+	@Wakeful
 	private void poll(PluginState ps) {
 		if (ps.endpoints.isEmpty()) return;
 		TransportId t = ps.plugin.getId();

bramble-core/src/main/java/org/briarproject/bramble/reporting/DevReporterImpl.java

@@ -29,6 +29,7 @@ import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 import javax.net.SocketFactory;
 
+import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.IoUtils.tryToClose;
 
@@ -100,11 +101,12 @@ class DevReporterImpl implements DevReporter, EventListener {
 	}
 
 	@Override
-	public void sendReports() {
+	public int sendReports() {
 		File reportDir = devConfig.getReportDir();
 		File[] reports = reportDir.listFiles();
+		int reportsSent = 0;
 		if (reports == null || reports.length == 0)
-			return; // No reports to send
+			return reportsSent; // No reports to send
 
 		LOG.info("Sending reports to developers");
 		for (File f : reports) {
@@ -116,13 +118,15 @@ class DevReporterImpl implements DevReporter, EventListener {
 				in = new FileInputStream(f);
 				IoUtils.copyAndClose(in, out);
 				f.delete();
+				reportsSent++;
 			} catch (IOException e) {
 				LOG.log(WARNING, "Failed to send reports", e);
 				tryToClose(out, LOG, WARNING);
 				tryToClose(in, LOG, WARNING);
-				return;
+				return reportsSent;
 			}
 		}
-		LOG.info("Reports sent");
+		if (LOG.isLoggable(INFO)) LOG.info(reportsSent + " report(s) sent");
+		return reportsSent;
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/system/ClockModule.java

@@ -0,0 +1,15 @@
+package org.briarproject.bramble.system;
+
+import org.briarproject.bramble.api.system.Clock;
+
+import dagger.Module;
+import dagger.Provides;
+
+@Module
+public class ClockModule {
+
+	@Provides
+	Clock provideClock() {
+		return new SystemClock();
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/system/DefaultTaskSchedulerModule.java

@@ -1,8 +1,7 @@
 package org.briarproject.bramble.system;
 
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
-import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.api.system.TaskScheduler;
-import org.briarproject.bramble.api.system.Scheduler;
 
 import java.util.concurrent.RejectedExecutionHandler;
 import java.util.concurrent.ScheduledExecutorService;
@@ -15,34 +14,26 @@ import dagger.Module;
 import dagger.Provides;
 
 @Module
-public class SystemModule {
+public class DefaultTaskSchedulerModule {
 
 	public static class EagerSingletons {
 		@Inject
-		@Scheduler
+		TaskScheduler scheduler;
-		ScheduledExecutorService scheduledExecutorService;
 	}
 
-	private final ScheduledExecutorService scheduler;
+	private final ScheduledExecutorService scheduledExecutorService;
 
-	public SystemModule() {
+	public DefaultTaskSchedulerModule() {
 		// Discard tasks that are submitted during shutdown
 		RejectedExecutionHandler policy =
 				new ScheduledThreadPoolExecutor.DiscardPolicy();
-		scheduler = new ScheduledThreadPoolExecutor(1, policy);
+		scheduledExecutorService = new ScheduledThreadPoolExecutor(1, policy);
-	}
-
-	@Provides
-	Clock provideClock() {
-		return new SystemClock();
 	}
 
 	@Provides
 	@Singleton
-	@Scheduler
+	TaskScheduler provideTaskScheduler(LifecycleManager lifecycleManager) {
-	ScheduledExecutorService provideScheduledExecutorService(
+		lifecycleManager.registerForShutdown(scheduledExecutorService);
-			LifecycleManager lifecycleManager) {
+		return new TaskSchedulerImpl(scheduledExecutorService);
-		lifecycleManager.registerForShutdown(scheduler);
-		return scheduler;
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/system/DefaultWakefulIoExecutorModule.java

@@ -0,0 +1,23 @@
+package org.briarproject.bramble.system;
+
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
+import org.briarproject.bramble.api.system.WakefulIoExecutor;
+
+import java.util.concurrent.Executor;
+
+import dagger.Module;
+import dagger.Provides;
+
+/**
+ * Provides a default implementation of {@link WakefulIoExecutor} for systems
+ * without wake locks.
+ */
+@Module
+public class DefaultWakefulIoExecutorModule {
+
+	@Provides
+	@WakefulIoExecutor
+	Executor provideWakefulIoExecutor(@IoExecutor Executor ioExecutor) {
+		return ioExecutor;
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/system/TaskSchedulerImpl.java

@@ -0,0 +1,43 @@
+package org.briarproject.bramble.system;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.TaskScheduler;
+
+import java.util.concurrent.Executor;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
+
+import javax.annotation.concurrent.ThreadSafe;
+
+/**
+ * A {@link TaskScheduler} that uses a {@link ScheduledExecutorService}.
+ */
+@ThreadSafe
+@NotNullByDefault
+class TaskSchedulerImpl implements TaskScheduler {
+
+	private final ScheduledExecutorService scheduledExecutorService;
+
+	TaskSchedulerImpl(ScheduledExecutorService scheduledExecutorService) {
+		this.scheduledExecutorService = scheduledExecutorService;
+	}
+
+	@Override
+	public Cancellable schedule(Runnable task, Executor executor, long delay,
+			TimeUnit unit) {
+		Runnable execute = () -> executor.execute(task);
+		ScheduledFuture<?> future =
+				scheduledExecutorService.schedule(execute, delay, unit);
+		return () -> future.cancel(false);
+	}
+
+	@Override
+	public Cancellable scheduleWithFixedDelay(Runnable task, Executor executor,
+			long delay, long interval, TimeUnit unit) {
+		Runnable execute = () -> executor.execute(task);
+		ScheduledFuture<?> future = scheduledExecutorService.
+				scheduleWithFixedDelay(execute, delay, interval, unit);
+		return () -> future.cancel(false);
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/transport/TransportKeyManagerFactoryImpl.java

@@ -6,10 +6,9 @@ import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.api.system.Scheduler;
+import org.briarproject.bramble.api.system.TaskScheduler;
 
 import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
 
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
@@ -22,14 +21,15 @@ class TransportKeyManagerFactoryImpl implements
 	private final DatabaseComponent db;
 	private final TransportCrypto transportCrypto;
 	private final Executor dbExecutor;
-	private final ScheduledExecutorService scheduler;
+	private final TaskScheduler scheduler;
 	private final Clock clock;
 
 	@Inject
 	TransportKeyManagerFactoryImpl(DatabaseComponent db,
 			TransportCrypto transportCrypto,
 			@DatabaseExecutor Executor dbExecutor,
-			@Scheduler ScheduledExecutorService scheduler, Clock clock) {
+			TaskScheduler scheduler,
+			Clock clock) {
 		this.db = db;
 		this.transportCrypto = transportCrypto;
 		this.dbExecutor = dbExecutor;

bramble-core/src/main/java/org/briarproject/bramble/transport/TransportKeyManagerImpl.java

@@ -6,12 +6,14 @@ import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.crypto.TransportCrypto;
 import org.briarproject.bramble.api.db.DatabaseComponent;
+import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.api.system.Scheduler;
+import org.briarproject.bramble.api.system.TaskScheduler;
+import org.briarproject.bramble.api.system.Wakeful;
 import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.StreamContext;
 import org.briarproject.bramble.api.transport.TransportKeySet;
@@ -24,7 +26,6 @@ import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.logging.Logger;
@@ -53,7 +54,7 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 	private final DatabaseComponent db;
 	private final TransportCrypto transportCrypto;
 	private final Executor dbExecutor;
-	private final ScheduledExecutorService scheduler;
+	private final TaskScheduler scheduler;
 	private final Clock clock;
 	private final TransportId transportId;
 	private final long timePeriodLength;
@@ -72,9 +73,12 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 			pendingContactOutContexts = new HashMap<>();
 
 	TransportKeyManagerImpl(DatabaseComponent db,
-			TransportCrypto transportCrypto, Executor dbExecutor,
+			TransportCrypto transportCrypto,
-			@Scheduler ScheduledExecutorService scheduler, Clock clock,
+			Executor dbExecutor,
-			TransportId transportId, long maxLatency) {
+			TaskScheduler scheduler,
+			Clock clock,
+			TransportId transportId,
+			long maxLatency) {
 		this.db = db;
 		this.transportCrypto = transportCrypto;
 		this.dbExecutor = dbExecutor;
@@ -196,17 +200,17 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 
 	private void scheduleKeyUpdate(long now) {
 		long delay = timePeriodLength - now % timePeriodLength;
-		scheduler.schedule((Runnable) this::updateKeys, delay, MILLISECONDS);
+		scheduler.schedule(this::updateKeys, dbExecutor, delay, MILLISECONDS);
 	}
 
+	@DatabaseExecutor
+	@Wakeful
 	private void updateKeys() {
-		dbExecutor.execute(() -> {
+		try {
-			try {
+			db.transaction(false, this::updateKeys);
-				db.transaction(false, this::updateKeys);
+		} catch (DbException e) {
-			} catch (DbException e) {
+			logException(LOG, WARNING, e);
-				logException(LOG, WARNING, e);
+		}
-			}
-		});
 	}
 
 	@Override
@@ -439,6 +443,8 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 		}
 	}
 
+	@DatabaseExecutor
+	@Wakeful
 	private void updateKeys(Transaction txn) throws DbException {
 		long now = clock.currentTimeMillis();
 		lock.lock();

bramble-core/src/test/java/org/briarproject/bramble/BrambleCoreIntegrationTestEagerSingletons.java

@@ -0,0 +1,18 @@
+package org.briarproject.bramble;
+
+import org.briarproject.bramble.system.DefaultTaskSchedulerModule;
+
+public interface BrambleCoreIntegrationTestEagerSingletons
+		extends BrambleCoreEagerSingletons {
+
+	void inject(DefaultTaskSchedulerModule.EagerSingletons init);
+
+	class Helper {
+
+		public static void injectEagerSingletons(
+				BrambleCoreIntegrationTestEagerSingletons c) {
+			BrambleCoreEagerSingletons.Helper.injectEagerSingletons(c);
+			c.inject(new DefaultTaskSchedulerModule.EagerSingletons());
+		}
+	}
+}

bramble-core/src/test/java/org/briarproject/bramble/contact/ContactExchangeIntegrationTest.java

@@ -1,6 +1,6 @@
 package org.briarproject.bramble.contact;
 
-import org.briarproject.bramble.BrambleCoreEagerSingletons;
+import org.briarproject.bramble.BrambleCoreIntegrationTestEagerSingletons;
 import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactManager;
@@ -62,11 +62,13 @@ public class ContactExchangeIntegrationTest extends BrambleTestCase {
 		alice = DaggerContactExchangeIntegrationTestComponent.builder()
 				.testDatabaseConfigModule(
 						new TestDatabaseConfigModule(aliceDir)).build();
-		BrambleCoreEagerSingletons.Helper.injectEagerSingletons(alice);
+		BrambleCoreIntegrationTestEagerSingletons.Helper
+				.injectEagerSingletons(alice);
 		bob = DaggerContactExchangeIntegrationTestComponent.builder()
 				.testDatabaseConfigModule(new TestDatabaseConfigModule(bobDir))
 				.build();
-		BrambleCoreEagerSingletons.Helper.injectEagerSingletons(bob);
+		BrambleCoreIntegrationTestEagerSingletons.Helper
+				.injectEagerSingletons(bob);
 		// Set up the devices and get the identities
 		aliceIdentity = setUp(alice, "Alice");
 		bobIdentity = setUp(bob, "Bob");

bramble-core/src/test/java/org/briarproject/bramble/contact/ContactExchangeIntegrationTestComponent.java

@@ -1,6 +1,6 @@
 package org.briarproject.bramble.contact;
 
-import org.briarproject.bramble.BrambleCoreEagerSingletons;
+import org.briarproject.bramble.BrambleCoreIntegrationTestEagerSingletons;
 import org.briarproject.bramble.BrambleCoreModule;
 import org.briarproject.bramble.api.connection.ConnectionManager;
 import org.briarproject.bramble.api.contact.ContactExchangeManager;
@@ -23,7 +23,7 @@ import dagger.Component;
 		BrambleCoreModule.class
 })
 interface ContactExchangeIntegrationTestComponent
-		extends BrambleCoreEagerSingletons {
+		extends BrambleCoreIntegrationTestEagerSingletons {
 
 	ConnectionManager getConnectionManager();
 

bramble-core/src/test/java/org/briarproject/bramble/plugin/PluginManagerImplTest.java

@@ -109,8 +109,8 @@ public class PluginManagerImplTest extends BrambleTestCase {
 			oneOf(duplexPlugin).stop();
 		}});
 
-		PluginManagerImpl p = new PluginManagerImpl(ioExecutor, eventBus,
+		PluginManagerImpl p = new PluginManagerImpl(ioExecutor, ioExecutor,
-				pluginConfig, connectionManager, settingsManager,
+				eventBus, pluginConfig, connectionManager, settingsManager,
 				transportPropertyManager);
 
 		// Two plugins should be started and stopped

bramble-core/src/test/java/org/briarproject/bramble/plugin/PollerImplTest.java

@@ -19,6 +19,8 @@ import org.briarproject.bramble.api.plugin.simplex.SimplexPlugin;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
 import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.api.system.TaskScheduler;
+import org.briarproject.bramble.api.system.TaskScheduler.Cancellable;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.ImmediateExecutor;
 import org.briarproject.bramble.test.RunAction;
@@ -30,8 +32,6 @@ import org.junit.Test;
 import java.security.SecureRandom;
 import java.util.List;
 import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledFuture;
 
 import static java.util.Arrays.asList;
 import static java.util.Collections.emptyList;
@@ -45,8 +45,7 @@ import static org.briarproject.bramble.test.TestUtils.getTransportId;
 
 public class PollerImplTest extends BrambleMockTestCase {
 
-	private final ScheduledExecutorService scheduler =
+	private final TaskScheduler scheduler = context.mock(TaskScheduler.class);
-			context.mock(ScheduledExecutorService.class);
 	private final ConnectionManager connectionManager =
 			context.mock(ConnectionManager.class);
 	private final ConnectionRegistry connectionRegistry =
@@ -56,10 +55,11 @@ public class PollerImplTest extends BrambleMockTestCase {
 	private final TransportPropertyManager transportPropertyManager =
 			context.mock(TransportPropertyManager.class);
 	private final Clock clock = context.mock(Clock.class);
-	private final ScheduledFuture future = context.mock(ScheduledFuture.class);
+	private final Cancellable cancellable = context.mock(Cancellable.class);
 	private final SecureRandom random;
 
 	private final Executor ioExecutor = new ImmediateExecutor();
+	private final Executor wakefulIoExecutor = new ImmediateExecutor();
 	private final TransportId transportId = getTransportId();
 	private final ContactId contactId = getContactId();
 	private final TransportProperties properties = new TransportProperties();
@@ -75,9 +75,9 @@ public class PollerImplTest extends BrambleMockTestCase {
 
 	@Before
 	public void setUp() {
-		poller = new PollerImpl(ioExecutor, scheduler, connectionManager,
+		poller = new PollerImpl(ioExecutor, wakefulIoExecutor, scheduler,
-				connectionRegistry, pluginManager, transportPropertyManager,
+				connectionManager, connectionRegistry, pluginManager,
-				random, clock);
+				transportPropertyManager, random, clock);
 	}
 
 	@Test
@@ -235,8 +235,9 @@ public class PollerImplTest extends BrambleMockTestCase {
 			oneOf(clock).currentTimeMillis();
 			will(returnValue(now));
 			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with((long) pollingInterval), with(MILLISECONDS));
+					with(ioExecutor), with((long) pollingInterval),
-			will(returnValue(future));
+					with(MILLISECONDS));
+			will(returnValue(cancellable));
 		}});
 
 		poller.eventOccurred(new ConnectionOpenedEvent(contactId, transportId,
@@ -263,8 +264,9 @@ public class PollerImplTest extends BrambleMockTestCase {
 			oneOf(clock).currentTimeMillis();
 			will(returnValue(now));
 			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with((long) pollingInterval), with(MILLISECONDS));
+					with(ioExecutor), with((long) pollingInterval),
-			will(returnValue(future));
+					with(MILLISECONDS));
+			will(returnValue(cancellable));
 			// Second event
 			// Get the plugin
 			oneOf(pluginManager).getPlugin(transportId);
@@ -305,8 +307,9 @@ public class PollerImplTest extends BrambleMockTestCase {
 			oneOf(clock).currentTimeMillis();
 			will(returnValue(now));
 			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with((long) pollingInterval), with(MILLISECONDS));
+					with(ioExecutor), with((long) pollingInterval),
-			will(returnValue(future));
+					with(MILLISECONDS));
+			will(returnValue(cancellable));
 			// Second event
 			// Get the plugin
 			oneOf(pluginManager).getPlugin(transportId);
@@ -319,9 +322,10 @@ public class PollerImplTest extends BrambleMockTestCase {
 			will(returnValue(pollingInterval - 2));
 			oneOf(clock).currentTimeMillis();
 			will(returnValue(now + 1));
-			oneOf(future).cancel(false);
+			oneOf(cancellable).cancel();
 			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with((long) pollingInterval - 2), with(MILLISECONDS));
+					with(ioExecutor), with((long) pollingInterval - 2),
+					with(MILLISECONDS));
 		}});
 
 		poller.eventOccurred(new ConnectionOpenedEvent(contactId, transportId,
@@ -346,9 +350,9 @@ public class PollerImplTest extends BrambleMockTestCase {
 			// Schedule a polling task immediately
 			oneOf(clock).currentTimeMillis();
 			will(returnValue(now));
-			oneOf(scheduler).schedule(with(any(Runnable.class)), with(0L),
+			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with(MILLISECONDS));
+					with(ioExecutor), with(0L), with(MILLISECONDS));
-			will(returnValue(future));
+			will(returnValue(cancellable));
 			will(new RunAction());
 			// Running the polling task schedules the next polling task
 			oneOf(plugin).getPollingInterval();
@@ -358,8 +362,9 @@ public class PollerImplTest extends BrambleMockTestCase {
 			oneOf(clock).currentTimeMillis();
 			will(returnValue(now));
 			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with((long) (pollingInterval * 0.5)), with(MILLISECONDS));
+					with(ioExecutor), with((long) (pollingInterval * 0.5)),
-			will(returnValue(future));
+					with(MILLISECONDS));
+			will(returnValue(cancellable));
 			// Get the transport properties and connected contacts
 			oneOf(transportPropertyManager).getRemoteProperties(transportId);
 			will(returnValue(singletonMap(contactId, properties)));
@@ -389,9 +394,9 @@ public class PollerImplTest extends BrambleMockTestCase {
 			// Schedule a polling task immediately
 			oneOf(clock).currentTimeMillis();
 			will(returnValue(now));
-			oneOf(scheduler).schedule(with(any(Runnable.class)), with(0L),
+			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with(MILLISECONDS));
+					with(ioExecutor), with(0L), with(MILLISECONDS));
-			will(returnValue(future));
+			will(returnValue(cancellable));
 			will(new RunAction());
 			// Running the polling task schedules the next polling task
 			oneOf(plugin).getPollingInterval();
@@ -401,8 +406,9 @@ public class PollerImplTest extends BrambleMockTestCase {
 			oneOf(clock).currentTimeMillis();
 			will(returnValue(now));
 			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with((long) (pollingInterval * 0.5)), with(MILLISECONDS));
+					with(ioExecutor), with((long) (pollingInterval * 0.5)),
-			will(returnValue(future));
+					with(MILLISECONDS));
+			will(returnValue(cancellable));
 			// Get the transport properties and connected contacts
 			oneOf(transportPropertyManager).getRemoteProperties(transportId);
 			will(returnValue(singletonMap(contactId, properties)));
@@ -430,11 +436,11 @@ public class PollerImplTest extends BrambleMockTestCase {
 			// Schedule a polling task immediately
 			oneOf(clock).currentTimeMillis();
 			will(returnValue(now));
-			oneOf(scheduler).schedule(with(any(Runnable.class)), with(0L),
+			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with(MILLISECONDS));
+					with(ioExecutor), with(0L), with(MILLISECONDS));
-			will(returnValue(future));
+			will(returnValue(cancellable));
 			// The plugin is deactivated before the task runs - cancel the task
-			oneOf(future).cancel(false);
+			oneOf(cancellable).cancel();
 		}});
 
 		poller.eventOccurred(new TransportActiveEvent(transportId));
@@ -455,8 +461,9 @@ public class PollerImplTest extends BrambleMockTestCase {
 			oneOf(clock).currentTimeMillis();
 			will(returnValue(now));
 			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with((long) pollingInterval), with(MILLISECONDS));
+					with(ioExecutor), with((long) pollingInterval),
-			will(returnValue(future));
+					with(MILLISECONDS));
+			will(returnValue(cancellable));
 		}});
 	}
 

bramble-core/src/test/java/org/briarproject/bramble/plugin/tcp/LanTcpPluginTest.java

@@ -22,11 +22,13 @@ import java.net.InetSocketAddress;
 import java.net.NetworkInterface;
 import java.net.ServerSocket;
 import java.net.Socket;
+import java.util.Collection;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import static java.net.NetworkInterface.getNetworkInterfaces;
+import static java.util.Collections.emptyList;
 import static java.util.Collections.list;
 import static java.util.concurrent.Executors.newCachedThreadPool;
 import static java.util.concurrent.TimeUnit.SECONDS;
@@ -51,7 +53,8 @@ public class LanTcpPluginTest extends BrambleTestCase {
 	@Before
 	public void setUp() {
 		callback = new Callback();
-		plugin = new LanTcpPlugin(ioExecutor, backoff, callback, 0, 0, 1000) {
+		plugin = new LanTcpPlugin(ioExecutor, ioExecutor, backoff, callback,
+				0, 0, 1000) {
 			@Override
 			protected boolean canConnectToOwnAddress() {
 				return true;
@@ -320,6 +323,11 @@ public class LanTcpPluginTest extends BrambleTestCase {
 			return local;
 		}
 
+		@Override
+		public Collection<TransportProperties> getRemoteProperties() {
+			return emptyList();
+		}
+
 		@Override
 		public void mergeSettings(Settings s) {
 		}

bramble-core/src/test/java/org/briarproject/bramble/properties/TransportPropertyManagerImplTest.java

@@ -8,11 +8,15 @@ import org.briarproject.bramble.api.data.BdfDictionary;
 import org.briarproject.bramble.api.data.BdfEntry;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.data.MetadataParser;
+import org.briarproject.bramble.api.db.CommitAction;
 import org.briarproject.bramble.api.db.DatabaseComponent;
+import org.briarproject.bramble.api.db.EventAction;
 import org.briarproject.bramble.api.db.Metadata;
 import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.properties.TransportProperties;
+import org.briarproject.bramble.api.properties.event.RemoteTransportPropertiesUpdatedEvent;
 import org.briarproject.bramble.api.sync.Group;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.Message;
@@ -45,6 +49,7 @@ import static org.briarproject.bramble.test.TestUtils.getMessage;
 import static org.briarproject.bramble.test.TestUtils.getRandomId;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
 public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 
@@ -59,23 +64,28 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 	private final Clock clock = context.mock(Clock.class);
 
 	private final Group localGroup = getGroup(CLIENT_ID, MAJOR_VERSION);
-	private final BdfDictionary fooPropertiesDict = BdfDictionary.of(
+	private final BdfDictionary fooPropertiesDict, barPropertiesDict;
-			new BdfEntry("fooKey1", "fooValue1"),
+	private final BdfDictionary discoveredPropertiesDict, mergedPropertiesDict;
-			new BdfEntry("fooKey2", "fooValue2")
-	);
-	private final BdfDictionary barPropertiesDict = BdfDictionary.of(
-			new BdfEntry("barKey1", "barValue1"),
-			new BdfEntry("barKey2", "barValue2")
-	);
 	private final TransportProperties fooProperties, barProperties;
+	private final TransportProperties discoveredProperties;
 
-	public TransportPropertyManagerImplTest() throws Exception {
+	public TransportPropertyManagerImplTest() {
 		fooProperties = new TransportProperties();
-		for (String key : fooPropertiesDict.keySet())
+		fooProperties.put("fooKey1", "fooValue1");
-			fooProperties.put(key, fooPropertiesDict.getString(key));
+		fooProperties.put("fooKey2", "fooValue2");
+		fooPropertiesDict = new BdfDictionary(fooProperties);
+
 		barProperties = new TransportProperties();
-		for (String key : barPropertiesDict.keySet())
+		barProperties.put("barKey1", "barValue1");
-			barProperties.put(key, barPropertiesDict.getString(key));
+		barProperties.put("barKey2", "barValue2");
+		barPropertiesDict = new BdfDictionary(barProperties);
+
+		discoveredProperties = new TransportProperties();
+		discoveredProperties.put("fooKey3", "fooValue3");
+		discoveredPropertiesDict = new BdfDictionary(discoveredProperties);
+
+		mergedPropertiesDict = new BdfDictionary(fooProperties);
+		mergedPropertiesDict.put("u:fooKey3", "fooValue3");
 	}
 
 	private TransportPropertyManagerImpl createInstance() {
@@ -221,6 +231,7 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 
 		TransportPropertyManagerImpl t = createInstance();
 		assertFalse(t.incomingMessage(txn, message, meta));
+		assertTrue(hasEvent(txn, RemoteTransportPropertiesUpdatedEvent.class));
 	}
 
 	@Test
@@ -259,6 +270,7 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 
 		TransportPropertyManagerImpl t = createInstance();
 		assertFalse(t.incomingMessage(txn, message, meta));
+		assertTrue(hasEvent(txn, RemoteTransportPropertiesUpdatedEvent.class));
 	}
 
 	@Test
@@ -292,10 +304,12 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 			// The update being delivered (version 3) should be deleted
 			oneOf(db).deleteMessage(txn, message.getId());
 			oneOf(db).deleteMessageMetadata(txn, message.getId());
+			// No event should be broadcast
 		}});
 
 		TransportPropertyManagerImpl t = createInstance();
 		assertFalse(t.incomingMessage(txn, message, meta));
+		assertFalse(hasEvent(txn, RemoteTransportPropertiesUpdatedEvent.class));
 	}
 
 	@Test
@@ -588,6 +602,9 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
 					contactGroup.getId());
 			will(returnValue(emptyMap()));
+			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(new BdfDictionary()));
 			expectStoreMessage(txn, contactGroup.getId(), "foo",
 					fooPropertiesDict, 1, true, true);
 		}});
@@ -596,6 +613,49 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		t.mergeLocalProperties(new TransportId("foo"), properties);
 	}
 
+	@Test
+	public void testMergingNewPropertiesCreatesUpdateWithReflectedProperties()
+			throws Exception {
+		Transaction txn = new Transaction(null, false);
+		Contact contact = getContact();
+		Group contactGroup = getGroup(CLIENT_ID, MAJOR_VERSION);
+		BdfDictionary contactGroupMeta = BdfDictionary.of(
+				new BdfEntry(GROUP_KEY_DISCOVERED, discoveredPropertiesDict)
+		);
+
+		context.checking(new DbExpectations() {{
+			oneOf(db).transaction(with(false), withDbRunnable(txn));
+			// There are no existing properties to merge with
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					localGroup.getId());
+			will(returnValue(emptyMap()));
+			// Store the new properties in the local group, version 1
+			expectStoreMessage(txn, localGroup.getId(), "foo",
+					fooPropertiesDict, 1, true, false);
+			// Store the new properties in each contact's group, version 1
+			oneOf(db).getContacts(txn);
+			will(returnValue(singletonList(contact)));
+			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
+					MAJOR_VERSION, contact);
+			will(returnValue(contactGroup));
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(emptyMap()));
+			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(contactGroupMeta));
+			// Reflect discovered properties
+			oneOf(clientHelper).parseAndValidateTransportProperties(
+					discoveredPropertiesDict);
+			will(returnValue(discoveredProperties));
+			expectStoreMessage(txn, contactGroup.getId(), "foo",
+					mergedPropertiesDict, 1, true, true);
+		}});
+
+		TransportPropertyManagerImpl t = createInstance();
+		t.mergeLocalProperties(new TransportId("foo"), fooProperties);
+	}
+
 	@Test
 	public void testMergingUpdatedPropertiesCreatesUpdate() throws Exception {
 		Transaction txn = new Transaction(null, false);
@@ -652,6 +712,9 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
 					contactGroup.getId());
 			will(returnValue(contactGroupMessageMetadata));
+			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(new BdfDictionary()));
 			expectStoreMessage(txn, contactGroup.getId(), "foo",
 					fooPropertiesDict, 2, true, true);
 			// Delete the previous update
@@ -662,6 +725,75 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		t.mergeLocalProperties(new TransportId("foo"), properties);
 	}
 
+	@Test
+	public void testMergingUpdatedPropertiesCreatesUpdateWithReflectedProperties()
+			throws Exception {
+		Transaction txn = new Transaction(null, false);
+		Contact contact = getContact();
+		Group contactGroup = getGroup(CLIENT_ID, MAJOR_VERSION);
+		BdfDictionary contactGroupMeta = BdfDictionary.of(
+				new BdfEntry(GROUP_KEY_DISCOVERED, discoveredPropertiesDict)
+		);
+		BdfDictionary oldMetadata = BdfDictionary.of(
+				new BdfEntry(MSG_KEY_TRANSPORT_ID, "foo"),
+				new BdfEntry(MSG_KEY_VERSION, 1),
+				new BdfEntry(MSG_KEY_LOCAL, true)
+		);
+		MessageId localGroupUpdateId = new MessageId(getRandomId());
+		Map<MessageId, BdfDictionary> localGroupMessageMetadata =
+				singletonMap(localGroupUpdateId, oldMetadata);
+		MessageId contactGroupUpdateId = new MessageId(getRandomId());
+		Map<MessageId, BdfDictionary> contactGroupMessageMetadata =
+				singletonMap(contactGroupUpdateId, oldMetadata);
+		TransportProperties oldProperties = new TransportProperties();
+		oldProperties.put("fooKey1", "oldFooValue1");
+		BdfDictionary oldPropertiesDict = BdfDictionary.of(
+				new BdfEntry("fooKey1", "oldFooValue1")
+		);
+		BdfList oldUpdate = BdfList.of("foo", 1, oldPropertiesDict);
+
+		context.checking(new DbExpectations() {{
+			oneOf(db).transaction(with(false), withDbRunnable(txn));
+			// Merge the new properties with the existing properties
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					localGroup.getId());
+			will(returnValue(localGroupMessageMetadata));
+			oneOf(clientHelper).getMessageAsList(txn, localGroupUpdateId);
+			will(returnValue(oldUpdate));
+			oneOf(clientHelper).parseAndValidateTransportProperties(
+					oldPropertiesDict);
+			will(returnValue(oldProperties));
+			// Store the merged properties in the local group, version 2
+			expectStoreMessage(txn, localGroup.getId(), "foo",
+					fooPropertiesDict, 2, true, false);
+			// Delete the previous update
+			oneOf(db).removeMessage(txn, localGroupUpdateId);
+			// Store the merged properties in each contact's group, version 2
+			oneOf(db).getContacts(txn);
+			will(returnValue(singletonList(contact)));
+			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
+					MAJOR_VERSION, contact);
+			will(returnValue(contactGroup));
+			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(contactGroupMessageMetadata));
+			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(contactGroupMeta));
+			// Reflect discovered properties
+			oneOf(clientHelper).parseAndValidateTransportProperties(
+					discoveredPropertiesDict);
+			will(returnValue(discoveredProperties));
+			expectStoreMessage(txn, contactGroup.getId(), "foo",
+					mergedPropertiesDict, 2, true, true);
+			// Delete the previous update
+			oneOf(db).removeMessage(txn, contactGroupUpdateId);
+		}});
+
+		TransportPropertyManagerImpl t = createInstance();
+		t.mergeLocalProperties(new TransportId("foo"), fooProperties);
+	}
+
 	private void expectGetLocalProperties(Transaction txn) throws Exception {
 		Map<MessageId, BdfDictionary> messageMetadata = new LinkedHashMap<>();
 		// The latest update for transport "foo" should be returned
@@ -719,4 +851,15 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 					false);
 		}});
 	}
+
+	private boolean hasEvent(Transaction txn,
+			Class<? extends Event> eventClass) {
+		for (CommitAction action : txn.getActions()) {
+			if (action instanceof EventAction) {
+				Event event = ((EventAction) action).getEvent();
+				if (eventClass.isInstance(event)) return true;
+			}
+		}
+		return false;
+	}
 }

bramble-core/src/test/java/org/briarproject/bramble/rendezvous/RendezvousPollerImplTest.java

@@ -26,6 +26,8 @@ import org.briarproject.bramble.api.rendezvous.event.RendezvousConnectionClosedE
 import org.briarproject.bramble.api.rendezvous.event.RendezvousConnectionOpenedEvent;
 import org.briarproject.bramble.api.rendezvous.event.RendezvousPollEvent;
 import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.api.system.TaskScheduler;
+import org.briarproject.bramble.api.system.TaskScheduler.Cancellable;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.CaptureArgumentAction;
 import org.briarproject.bramble.test.DbExpectations;
@@ -37,7 +39,6 @@ import org.junit.Test;
 
 import java.util.Random;
 import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.atomic.AtomicReference;
 
 import static java.util.Collections.emptyList;
@@ -60,8 +61,7 @@ import static org.briarproject.bramble.test.TestUtils.getTransportProperties;
 
 public class RendezvousPollerImplTest extends BrambleMockTestCase {
 
-	private final ScheduledExecutorService scheduler =
+	private final TaskScheduler scheduler = context.mock(TaskScheduler.class);
-			context.mock(ScheduledExecutorService.class);
 	private final DatabaseComponent db = context.mock(DatabaseComponent.class);
 	private final IdentityManager identityManager =
 			context.mock(IdentityManager.class);
@@ -80,6 +80,7 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 			context.mock(KeyMaterialSource.class);
 	private final RendezvousEndpoint rendezvousEndpoint =
 			context.mock(RendezvousEndpoint.class);
+	private final Cancellable cancellable = context.mock(Cancellable.class);
 
 	private final Executor ioExecutor = new ImmediateExecutor();
 	private final PendingContact pendingContact = getPendingContact();
@@ -108,7 +109,7 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 		long beforeExpiry = pendingContact.getTimestamp()
 				+ RENDEZVOUS_TIMEOUT_MS - 1000;
 		long afterExpiry = beforeExpiry + POLLING_INTERVAL_MS;
-		AtomicReference<Runnable> capturePollTask = new AtomicReference<>();
+		AtomicReference<Runnable> capturePollTask;
 
 		// Start the service
 		context.checking(new DbExpectations() {{
@@ -122,21 +123,17 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(new PredicateMatcher<>(
 					PendingContactStateChangedEvent.class, e ->
 					e.getPendingContactState() == OFFLINE)));
-			// Capture the poll task
-			oneOf(scheduler).scheduleAtFixedRate(with(any(Runnable.class)),
-					with(POLLING_INTERVAL_MS), with(POLLING_INTERVAL_MS),
-					with(MILLISECONDS));
-			will(new CaptureArgumentAction<>(capturePollTask, Runnable.class,
-					0));
 		}});
 
 		expectDeriveRendezvousKey();
+		capturePollTask = expectSchedulePolling();
 
 		rendezvousPoller.startService();
 		context.assertIsSatisfied();
 
-		// Run the poll task - pending contact expires
+		// Run the poll task - pending contact expires, polling is cancelled
 		expectPendingContactExpires(afterExpiry);
+		expectCancelPolling();
 
 		capturePollTask.get().run();
 	}
@@ -158,10 +155,6 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(new PredicateMatcher<>(
 					PendingContactStateChangedEvent.class, e ->
 					e.getPendingContactState() == FAILED)));
-			// Schedule the poll task
-			oneOf(scheduler).scheduleAtFixedRate(with(any(Runnable.class)),
-					with(POLLING_INTERVAL_MS), with(POLLING_INTERVAL_MS),
-					with(MILLISECONDS));
 		}});
 
 		rendezvousPoller.startService();
@@ -184,7 +177,8 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 		rendezvousPoller.eventOccurred(new TransportActiveEvent(transportId));
 		context.assertIsSatisfied();
 
-		// Add the pending contact - endpoint should be created and polled
+		// Add the pending contact - endpoint should be created and polled,
+		// polling should be scheduled
 		expectAddPendingContact(beforeExpiry, WAITING_FOR_CONNECTION);
 		expectDeriveRendezvousKey();
 		expectCreateEndpoint();
@@ -201,12 +195,16 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 					any(ConnectionHandler.class)))));
 		}});
 
+		expectSchedulePolling();
+
 		rendezvousPoller.eventOccurred(
 				new PendingContactAddedEvent(pendingContact));
 		context.assertIsSatisfied();
 
-		// Remove the pending contact - endpoint should be closed
+		// Remove the pending contact - endpoint should be closed,
+		// polling should be cancelled
 		expectCloseEndpoint();
+		expectCancelPolling();
 
 		rendezvousPoller.eventOccurred(
 				new PendingContactRemovedEvent(pendingContact.getId()));
@@ -222,10 +220,10 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 		long beforeExpiry = pendingContact.getTimestamp()
 				+ RENDEZVOUS_TIMEOUT_MS - 1000;
 		long afterExpiry = beforeExpiry + POLLING_INTERVAL_MS;
+		AtomicReference<Runnable> capturePollTask;
 
-		// Start the service, capturing the poll task
+		// Start the service
-		AtomicReference<Runnable> capturePollTask =
+		expectStartupWithNoPendingContacts();
-				expectStartupWithNoPendingContacts();
 
 		rendezvousPoller.startService();
 		context.assertIsSatisfied();
@@ -236,7 +234,8 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 		rendezvousPoller.eventOccurred(new TransportActiveEvent(transportId));
 		context.assertIsSatisfied();
 
-		// Add the pending contact - endpoint should be created and polled
+		// Add the pending contact - endpoint should be created and polled,
+		// polling should be scheduled
 		expectAddPendingContact(beforeExpiry, WAITING_FOR_CONNECTION);
 		expectDeriveRendezvousKey();
 		expectCreateEndpoint();
@@ -253,13 +252,17 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 					any(ConnectionHandler.class)))));
 		}});
 
+		capturePollTask = expectSchedulePolling();
+
 		rendezvousPoller.eventOccurred(
 				new PendingContactAddedEvent(pendingContact));
 		context.assertIsSatisfied();
 
-		// Run the poll task - pending contact expires, endpoint is closed
+		// Run the poll task - pending contact expires, endpoint is closed,
+		// polling is cancelled
 		expectPendingContactExpires(afterExpiry);
 		expectCloseEndpoint();
+		expectCancelPolling();
 
 		capturePollTask.get().run();
 		context.assertIsSatisfied();
@@ -287,6 +290,7 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 		// Add the pending contact - no endpoints should be created yet
 		expectAddPendingContact(beforeExpiry, OFFLINE);
 		expectDeriveRendezvousKey();
+		expectSchedulePolling();
 
 		rendezvousPoller.eventOccurred(
 				new PendingContactAddedEvent(pendingContact));
@@ -308,6 +312,8 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 		context.assertIsSatisfied();
 
 		// Remove the pending contact - endpoint is already closed
+		expectCancelPolling();
+
 		rendezvousPoller.eventOccurred(
 				new PendingContactRemovedEvent(pendingContact.getId()));
 	}
@@ -349,8 +355,9 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 		rendezvousPoller.startService();
 		context.assertIsSatisfied();
 
-		// Run the poll task - pending contact expires
+		// Run the poll task - pending contact expires, polling is cancelled
 		expectPendingContactExpires(afterExpiry);
+		expectCancelPolling();
 
 		capturePollTask.get().run();
 		context.assertIsSatisfied();
@@ -386,8 +393,9 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 				new RendezvousConnectionOpenedEvent(pendingContact.getId()));
 		context.assertIsSatisfied();
 
-		// Run the poll task - pending contact expires
+		// Run the poll task - pending contact expires, polling is cancelled
 		expectPendingContactExpires(afterExpiry);
+		expectCancelPolling();
 
 		capturePollTask.get().run();
 		context.assertIsSatisfied();
@@ -418,8 +426,9 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 				new RendezvousConnectionOpenedEvent(pendingContact.getId()));
 		context.assertIsSatisfied();
 
-		// Run the poll task - pending contact expires
+		// Run the poll task - pending contact expires, polling is cancelled
 		expectPendingContactExpires(afterExpiry);
+		expectCancelPolling();
 
 		capturePollTask.get().run();
 		context.assertIsSatisfied();
@@ -448,6 +457,8 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 		context.assertIsSatisfied();
 
 		// Pending contact is removed - no event should be broadcast
+		expectCancelPolling();
+
 		rendezvousPoller.eventOccurred(
 				new PendingContactRemovedEvent(pendingContact.getId()));
 		context.assertIsSatisfied();
@@ -457,25 +468,35 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 				pendingContact.getId(), false));
 	}
 
-	private AtomicReference<Runnable> expectStartupWithNoPendingContacts()
+	private AtomicReference<Runnable> expectSchedulePolling() {
-			throws Exception {
-		Transaction txn = new Transaction(null, true);
 		AtomicReference<Runnable> capturePollTask = new AtomicReference<>();
 
+		context.checking(new Expectations() {{
+			oneOf(scheduler).scheduleWithFixedDelay(with(any(Runnable.class)),
+					with(any(Executor.class)), with(POLLING_INTERVAL_MS),
+					with(POLLING_INTERVAL_MS), with(MILLISECONDS));
+			will(doAll(new CaptureArgumentAction<>(capturePollTask,
+					Runnable.class, 0), returnValue(cancellable)));
+		}});
+
+		return capturePollTask;
+	}
+
+	private void expectCancelPolling() {
+		context.checking(new Expectations() {{
+			oneOf(cancellable).cancel();
+		}});
+	}
+
+	private void expectStartupWithNoPendingContacts() throws Exception {
+		Transaction txn = new Transaction(null, true);
+
 		context.checking(new DbExpectations() {{
 			// Load the pending contacts
 			oneOf(db).transaction(with(true), withDbRunnable(txn));
 			oneOf(db).getPendingContacts(txn);
 			will(returnValue(emptyList()));
-			// Capture the poll task
-			oneOf(scheduler).scheduleAtFixedRate(with(any(Runnable.class)),
-					with(POLLING_INTERVAL_MS), with(POLLING_INTERVAL_MS),
-					with(MILLISECONDS));
-			will(new CaptureArgumentAction<>(capturePollTask, Runnable.class,
-					0));
 		}});
-
-		return capturePollTask;
 	}
 
 	private void expectAddPendingContact(long now,
@@ -531,7 +552,6 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 	private AtomicReference<Runnable> expectStartupWithPendingContact(long now)
 			throws Exception {
 		Transaction txn = new Transaction(null, true);
-		AtomicReference<Runnable> capturePollTask = new AtomicReference<>();
 
 		context.checking(new DbExpectations() {{
 			// Load the pending contacts
@@ -544,17 +564,10 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(new PredicateMatcher<>(
 					PendingContactStateChangedEvent.class, e ->
 					e.getPendingContactState() == OFFLINE)));
-			// Capture the poll task
-			oneOf(scheduler).scheduleAtFixedRate(with(any(Runnable.class)),
-					with(POLLING_INTERVAL_MS), with(POLLING_INTERVAL_MS),
-					with(MILLISECONDS));
-			will(new CaptureArgumentAction<>(capturePollTask, Runnable.class,
-					0));
 		}});
 
 		expectDeriveRendezvousKey();
-
+		return expectSchedulePolling();
-		return capturePollTask;
 	}
 
 	private void expectPendingContactExpires(long now) {

bramble-core/src/test/java/org/briarproject/bramble/sync/SyncIntegrationTest.java

@@ -1,6 +1,6 @@
 package org.briarproject.bramble.sync;
 
-import org.briarproject.bramble.BrambleCoreEagerSingletons;
+import org.briarproject.bramble.BrambleCoreIntegrationTestEagerSingletons;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.crypto.TransportCrypto;
@@ -73,7 +73,8 @@ public class SyncIntegrationTest extends BrambleTestCase {
 
 		SyncIntegrationTestComponent component =
 				DaggerSyncIntegrationTestComponent.builder().build();
-		BrambleCoreEagerSingletons.Helper.injectEagerSingletons(component);
+		BrambleCoreIntegrationTestEagerSingletons.Helper
+				.injectEagerSingletons(component);
 		component.inject(this);
 
 		contactId = getContactId();

bramble-core/src/test/java/org/briarproject/bramble/sync/SyncIntegrationTestComponent.java

@@ -1,6 +1,6 @@
 package org.briarproject.bramble.sync;
 
-import org.briarproject.bramble.BrambleCoreEagerSingletons;
+import org.briarproject.bramble.BrambleCoreIntegrationTestEagerSingletons;
 import org.briarproject.bramble.BrambleCoreModule;
 import org.briarproject.bramble.test.BrambleCoreIntegrationTestModule;
 
@@ -13,7 +13,8 @@ import dagger.Component;
 		BrambleCoreIntegrationTestModule.class,
 		BrambleCoreModule.class
 })
-interface SyncIntegrationTestComponent extends BrambleCoreEagerSingletons {
+interface SyncIntegrationTestComponent extends
+		BrambleCoreIntegrationTestEagerSingletons {
 
 	void inject(SyncIntegrationTest testCase);
 }

bramble-core/src/test/java/org/briarproject/bramble/test/BrambleCoreIntegrationTestModule.java

@@ -3,6 +3,8 @@ package org.briarproject.bramble.test;
 import org.briarproject.bramble.api.FeatureFlags;
 import org.briarproject.bramble.battery.DefaultBatteryManagerModule;
 import org.briarproject.bramble.event.DefaultEventExecutorModule;
+import org.briarproject.bramble.system.DefaultTaskSchedulerModule;
+import org.briarproject.bramble.system.DefaultWakefulIoExecutorModule;
 
 import dagger.Module;
 import dagger.Provides;
@@ -10,6 +12,8 @@ import dagger.Provides;
 @Module(includes = {
 		DefaultBatteryManagerModule.class,
 		DefaultEventExecutorModule.class,
+		DefaultTaskSchedulerModule.class,
+		DefaultWakefulIoExecutorModule.class,
 		TestDatabaseConfigModule.class,
 		TestPluginConfigModule.class,
 		TestSecureRandomModule.class

bramble-core/src/test/java/org/briarproject/bramble/transport/TransportKeyManagerImplTest.java

@@ -8,6 +8,7 @@ import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.api.system.TaskScheduler;
 import org.briarproject.bramble.api.transport.IncomingKeys;
 import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.OutgoingKeys;
@@ -29,7 +30,6 @@ import java.util.Collection;
 import java.util.List;
 import java.util.Random;
 import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
 
 import static java.util.Arrays.asList;
 import static java.util.Collections.singletonList;
@@ -55,8 +55,7 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 	private final TransportCrypto transportCrypto =
 			context.mock(TransportCrypto.class);
 	private final Executor dbExecutor = context.mock(Executor.class);
-	private final ScheduledExecutorService scheduler =
+	private final TaskScheduler scheduler = context.mock(TaskScheduler.class);
-			context.mock(ScheduledExecutorService.class);
 	private final Clock clock = context.mock(Clock.class);
 
 	private final TransportId transportId = getTransportId();
@@ -118,7 +117,8 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 					new TransportKeySet(keySetId, contactId, null, updated)));
 			// Schedule a key update at the start of the next time period
 			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with(timePeriodLength - 1), with(MILLISECONDS));
+					with(dbExecutor), with(timePeriodLength - 1),
+					with(MILLISECONDS));
 		}});
 
 		transportKeyManager.start(txn);
@@ -421,9 +421,8 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 			}
 			// Schedule a key update at the start of the next time period
 			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with(timePeriodLength), with(MILLISECONDS));
+					with(dbExecutor), with(timePeriodLength),
-			will(new RunAction());
+					with(MILLISECONDS));
-			oneOf(dbExecutor).execute(with(any(Runnable.class)));
 			will(new RunAction());
 			// Start a transaction for updating keys
 			oneOf(db).transaction(with(false), withDbRunnable(txn1));
@@ -446,7 +445,8 @@ public class TransportKeyManagerImplTest extends BrambleMockTestCase {
 					new TransportKeySet(keySetId, contactId, null, updated)));
 			// Schedule a key update at the start of the next time period
 			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with(timePeriodLength), with(MILLISECONDS));
+					with(dbExecutor), with(timePeriodLength),
+					with(MILLISECONDS));
 		}});
 
 		transportKeyManager.start(txn);