FCM improvements.

src/org/thoughtcrime/securesms/util/WakeLockUtil.java

@@ -0,0 +1,56 @@
+package org.thoughtcrime.securesms.util;
+
+import android.content.Context;
+import android.os.PowerManager;
+import android.os.PowerManager.WakeLock;
+import android.support.annotation.NonNull;
+
+import org.thoughtcrime.securesms.logging.Log;
+
+public class WakeLockUtil {
+
+  private static final String TAG = WakeLockUtil.class.getSimpleName();
+
+  /**
+   * Run a runnable with a wake lock. Ensures that the lock is safely acquired and released.
+   */
+  public static void runWithLock(@NonNull Context context, int lockType, long timeout, @NonNull String tag, @NonNull Runnable task) {
+    WakeLock wakeLock = null;
+    try {
+      wakeLock = acquire(context, lockType, timeout, tag);
+      task.run();
+    } finally {
+      if (wakeLock != null) {
+        release(wakeLock, tag);
+      }
+    }
+  }
+
+  public static WakeLock acquire(@NonNull Context context, int lockType, long timeout, @NonNull String tag) {
+    try {
+      PowerManager powerManager = ServiceUtil.getPowerManager(context);
+      WakeLock     wakeLock     = powerManager.newWakeLock(lockType, tag);
+
+      wakeLock.acquire(timeout);
+      Log.d(TAG, "Acquired wakelock with tag: " + tag);
+
+      return wakeLock;
+    } catch (Exception e) {
+      Log.w(TAG, "Failed to acquire wakelock with tag: " + tag, e);
+      return null;
+    }
+  }
+
+  public static void release(@NonNull WakeLock wakeLock, @NonNull String tag) {
+    try {
+      if (wakeLock.isHeld()) {
+        wakeLock.release();
+        Log.d(TAG, "Released wakelock with tag: " + tag);
+      } else {
+        Log.d(TAG, "Wakelock wasn't held at time of release: " + tag);
+      }
+    } catch (Exception e) {
+      Log.w(TAG, "Failed to release wakelock with tag: " + tag, e);
+    }
+  }
+}