Merge branch 'poller-refactoring' into 'master'

Poller refactoring, replace Timer with ScheduledExecutorService

* Replace Timer with ScheduledExecutorService (closes #258)
* Move automatic connection logic from PluginManager to Poller
* Reschedule polling when connections are opened or closed, making the poller more responsive to reductions in the polling interval


See merge request !180

briar-core/src/org/briarproject/system/SystemModule.java

@@ -1,23 +1,41 @@
 package org.briarproject.system;
 
+import org.briarproject.api.lifecycle.LifecycleManager;
 import org.briarproject.api.system.Clock;
-import org.briarproject.api.system.LocationUtils;
-import org.briarproject.api.system.SeedProvider;
-import org.briarproject.api.system.Timer;
+
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
 
 import dagger.Module;
 import dagger.Provides;
 
 @Module
 public class SystemModule {
+
+	public static class EagerSingletons {
+		@Inject
+		ScheduledExecutorService scheduledExecutorService;
+	}
+
+	private final ScheduledExecutorService scheduler;
+
+	public SystemModule() {
+		scheduler = Executors.newSingleThreadScheduledExecutor();
+	}
+
 	@Provides
 	Clock provideClock() {
 		return new SystemClock();
 	}
 
 	@Provides
-	Timer provideTimer() {
-		return new SystemTimer();
+	@Singleton
+	ScheduledExecutorService provideScheduledExecutorService(
+			LifecycleManager lifecycleManager) {
+		lifecycleManager.registerForShutdown(scheduler);
+		return scheduler;
 	}
-
 }

briar-core/src/org/briarproject/system/SystemTimer.java

@@ -1,31 +0,0 @@
-package org.briarproject.system;
-
-import java.util.TimerTask;
-
-import org.briarproject.api.system.Timer;
-
-/** Default timer implementation. */
-public class SystemTimer implements Timer {
-
-	private final java.util.Timer timer = new java.util.Timer(true);
-
-	public void cancel() {
-		timer.cancel();
-	}
-
-	public int purge() {
-		return timer.purge();
-	}
-
-	public void schedule(TimerTask task, long delay) {
-		timer.schedule(task, delay);
-	}
-
-	public void schedule(TimerTask task, long delay, long period) {
-		timer.schedule(task, delay, period);
-	}
-
-	public void scheduleAtFixedRate(TimerTask task, long delay, long period) {
-		timer.scheduleAtFixedRate(task, delay, period);
-	}
-}