Refactor wake lock to use existing ScheduledExecutorService.

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

@@ -0,0 +1,90 @@
+package org.briarproject.bramble.util;
+
+import android.os.PowerManager;
+
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Logger;
+
+import static java.util.logging.Level.INFO;
+
+public class RenewableWakeLock {
+
+	private static final Logger LOG =
+			Logger.getLogger(RenewableWakeLock.class.getName());
+
+	private final PowerManager powerManager;
+	private final ScheduledExecutorService scheduler;
+	private final int levelAndFlags;
+	private final String tag;
+	private final long duration;
+	private final TimeUnit timeUnit;
+	private final Runnable renewTask;
+
+	private final Object lock = new Object();
+	private PowerManager.WakeLock wakeLock; // Locking: lock
+	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;
+		this.duration = duration;
+		this.timeUnit = timeUnit;
+		renewTask = new Runnable() {
+			@Override
+			public void run() {
+				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();
+			future = scheduler.schedule(renewTask, duration, timeUnit);
+		}
+	}
+
+	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();
+			oldWakeLock.release();
+			future = scheduler.schedule(renewTask, duration, timeUnit);
+		}
+	}
+
+	public void release() {
+		if (LOG.isLoggable(INFO)) LOG.info("Releasing wake lock " + tag );
+		synchronized (lock) {
+			if (wakeLock == null) {
+				LOG.info("Already released");
+				return;
+			}
+			future.cancel(false);
+			future = null;
+			wakeLock.release();
+			wakeLock = null;
+		}
+	}
+}
+

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

@@ -1,47 +0,0 @@
-package org.briarproject.bramble.util;
-
-import android.content.Context;
-
-import java.util.concurrent.Executors;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ThreadFactory;
-import java.util.concurrent.TimeUnit;
-
-public class ScheduledExecutorServiceWakeLock {
-
-	final Context appContext;
-
-	private static final ThreadFactory THREAD_FACTORY = new ThreadFactory() {
-		@Override
-		public Thread newThread(Runnable r) {
-			Thread t = new Thread(r);
-			t.setDaemon(true);
-			return t;
-		}
-	};
-
-	private ScheduledExecutorService scheduledExecutorService = null; // Locking: this
-	private Runnable runnable;
-
-	public ScheduledExecutorServiceWakeLock(Context appContext) {
-		this.appContext = appContext;
-	}
-
-	public void setRunnable(Runnable r){
-		runnable = r;
-	}
-
-	public synchronized void setAlarm(long delay, TimeUnit unit) {
-		if(runnable == null)
-			return;
-		if (scheduledExecutorService == null)
-			scheduledExecutorService = Executors.newSingleThreadScheduledExecutor(THREAD_FACTORY);
-		scheduledExecutorService.schedule(runnable, delay, unit);
-	}
-
-	public synchronized void cancelAlarm() {
-		if (scheduledExecutorService == null) throw new IllegalStateException();
-		scheduledExecutorService.shutdownNow();
-		scheduledExecutorService = null;
-	}
-}