Allow setting a Clock for the main playback thread.

This allows to inject a FakeClock for tests. Other playback components
(e.g. some media sources) still use SystemClock but they can be amended
in the future if needed.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=179921889

library/core/src/main/java/com/google/android/exoplayer2/DefaultMediaClock.java

@@ -47,16 +47,6 @@ import com.google.android.exoplayer2.util.StandaloneMediaClock;
   private @Nullable MediaClock rendererClock;
 
   /**
-   * Creates a new instance with listener for playback parameter changes.
-   *
-   * @param listener A {@link PlaybackParameterListener} to listen for playback parameter
-   *     changes.
-   */
-  public DefaultMediaClock(PlaybackParameterListener listener) {
-    this(listener, Clock.DEFAULT);
-  }
-
-  /**
    * Creates a new instance with listener for playback parameter changes and a {@link Clock} to use
    * for the standalone clock implementation.
    *

library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerFactory.java

@@ -20,6 +20,7 @@ import android.support.annotation.Nullable;
 import com.google.android.exoplayer2.drm.DrmSessionManager;
 import com.google.android.exoplayer2.drm.FrameworkMediaCrypto;
 import com.google.android.exoplayer2.trackselection.TrackSelector;
+import com.google.android.exoplayer2.util.Clock;
 
 /**
  * A factory for {@link ExoPlayer} instances.
@@ -160,7 +161,7 @@ public final class ExoPlayerFactory {
    */
   public static ExoPlayer newInstance(Renderer[] renderers, TrackSelector trackSelector,
       LoadControl loadControl) {
-    return new ExoPlayerImpl(renderers, trackSelector, loadControl);
+    return new ExoPlayerImpl(renderers, trackSelector, loadControl, Clock.DEFAULT);
   }
 
 }

library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImpl.java

@@ -31,6 +31,7 @@ import com.google.android.exoplayer2.trackselection.TrackSelectionArray;
 import com.google.android.exoplayer2.trackselection.TrackSelector;
 import com.google.android.exoplayer2.trackselection.TrackSelectorResult;
 import com.google.android.exoplayer2.util.Assertions;
+import com.google.android.exoplayer2.util.Clock;
 import com.google.android.exoplayer2.util.Util;
 import java.util.ArrayList;
 import java.util.List;
@@ -75,9 +76,11 @@ import java.util.concurrent.CopyOnWriteArraySet;
    * @param renderers The {@link Renderer}s that will be used by the instance.
    * @param trackSelector The {@link TrackSelector} that will be used by the instance.
    * @param loadControl The {@link LoadControl} that will be used by the instance.
+   * @param clock The {@link Clock} that will be used by the instance.
    */
   @SuppressLint("HandlerLeak")
-  public ExoPlayerImpl(Renderer[] renderers, TrackSelector trackSelector, LoadControl loadControl) {
+  public ExoPlayerImpl(
+      Renderer[] renderers, TrackSelector trackSelector, LoadControl loadControl, Clock clock) {
     Log.i(TAG, "Init " + Integer.toHexString(System.identityHashCode(this)) + " ["
         + ExoPlayerLibraryInfo.VERSION_SLASHY + "] [" + Util.DEVICE_DEBUG_INFO + "]");
     Assertions.checkState(renderers.length > 0);
@@ -116,7 +119,8 @@ import java.util.concurrent.CopyOnWriteArraySet;
             repeatMode,
             shuffleModeEnabled,
             eventHandler,
-            this);
+            this,
+            clock);
     internalPlayerHandler = new Handler(internalPlayer.getPlaybackLooper());
   }
 

library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImplInternal.java

@@ -39,6 +39,8 @@ import com.google.android.exoplayer2.trackselection.TrackSelectionArray;
 import com.google.android.exoplayer2.trackselection.TrackSelector;
 import com.google.android.exoplayer2.trackselection.TrackSelectorResult;
 import com.google.android.exoplayer2.util.Assertions;
+import com.google.android.exoplayer2.util.Clock;
+import com.google.android.exoplayer2.util.HandlerWrapper;
 import com.google.android.exoplayer2.util.TraceUtil;
 import com.google.android.exoplayer2.util.Util;
 import java.io.IOException;
@@ -102,7 +104,7 @@ import java.util.Collections;
   private final TrackSelector trackSelector;
   private final TrackSelectorResult emptyTrackSelectorResult;
   private final LoadControl loadControl;
-  private final Handler handler;
+  private final HandlerWrapper handler;
   private final HandlerThread internalPlaybackThread;
   private final Handler eventHandler;
   private final ExoPlayer player;
@@ -126,7 +128,6 @@ import java.util.Collections;
   private boolean rebuffering;
   private @Player.RepeatMode int repeatMode;
   private boolean shuffleModeEnabled;
-  private long elapsedRealtimeUs;
 
   private int pendingPrepareCount;
   private SeekPosition pendingInitialSeekPosition;
@@ -146,7 +147,8 @@ import java.util.Collections;
       @Player.RepeatMode int repeatMode,
       boolean shuffleModeEnabled,
       Handler eventHandler,
-      ExoPlayer player) {
+      ExoPlayer player,
+      Clock clock) {
     this.renderers = renderers;
     this.trackSelector = trackSelector;
     this.emptyTrackSelectorResult = emptyTrackSelectorResult;
@@ -170,7 +172,7 @@ import java.util.Collections;
       renderers[i].setIndex(i);
       rendererCapabilities[i] = renderers[i].getCapabilities();
     }
-    mediaClock = new DefaultMediaClock(this);
+    mediaClock = new DefaultMediaClock(this, clock);
     customMessageInfos = new ArrayList<>();
     enabledRenderers = new Renderer[0];
     window = new Timeline.Window();
@@ -183,7 +185,7 @@ import java.util.Collections;
     internalPlaybackThread = new HandlerThread("ExoPlayerImplInternal:Handler",
         Process.THREAD_PRIORITY_AUDIO);
     internalPlaybackThread.start();
-    handler = new Handler(internalPlaybackThread.getLooper(), this);
+    handler = clock.createHandler(internalPlaybackThread.getLooper(), this);
   }
 
   public void prepare(MediaSource mediaSource, boolean resetPosition) {
@@ -527,7 +529,6 @@ import java.util.Collections;
       maybeTriggerCustomMessages(playbackInfo.positionUs, periodPositionUs);
       playbackInfo.positionUs = periodPositionUs;
     }
-    elapsedRealtimeUs = SystemClock.elapsedRealtime() * 1000;
 
     // Update the buffered position.
     long bufferedPositionUs = enabledRenderers.length == 0 ? C.TIME_END_OF_SOURCE
@@ -549,16 +550,19 @@ import java.util.Collections;
     TraceUtil.beginSection("doSomeWork");
 
     updatePlaybackPositions();
+    long rendererPositionElapsedRealtimeUs = SystemClock.elapsedRealtime() * 1000;
+
     playingPeriodHolder.mediaPeriod.discardBuffer(playbackInfo.positionUs - backBufferDurationUs,
         retainBackBufferFromKeyframe);
 
     boolean allRenderersEnded = true;
     boolean allRenderersReadyOrEnded = true;
+
     for (Renderer renderer : enabledRenderers) {
       // TODO: Each renderer should return the maximum delay before which it wishes to be called
       // again. The minimum of these values should then be used as the delay before the next
       // invocation of this method.
-      renderer.render(rendererPositionUs, elapsedRealtimeUs);
+      renderer.render(rendererPositionUs, rendererPositionElapsedRealtimeUs);
       allRenderersEnded = allRenderersEnded && renderer.isEnded();
       // Determine whether the renderer is ready (or ended). We override to assume the renderer is
       // ready if it needs the next sample stream. This is necessary to avoid getting stuck if
@@ -625,13 +629,7 @@ import java.util.Collections;
 
   private void scheduleNextWork(long thisOperationStartTimeMs, long intervalMs) {
     handler.removeMessages(MSG_DO_SOME_WORK);
-    long nextOperationStartTimeMs = thisOperationStartTimeMs + intervalMs;
-    long nextOperationDelayMs = nextOperationStartTimeMs - SystemClock.elapsedRealtime();
-    if (nextOperationDelayMs <= 0) {
-      handler.sendEmptyMessage(MSG_DO_SOME_WORK);
-    } else {
-      handler.sendEmptyMessageDelayed(MSG_DO_SOME_WORK, nextOperationDelayMs);
-    }
+    handler.sendEmptyMessageDelayed(MSG_DO_SOME_WORK, intervalMs, thisOperationStartTimeMs);
   }
 
   private void seekToInternal(SeekPosition seekPosition) throws ExoPlaybackException {

library/core/src/main/java/com/google/android/exoplayer2/SimpleExoPlayer.java

@@ -38,6 +38,7 @@ import com.google.android.exoplayer2.text.Cue;
 import com.google.android.exoplayer2.text.TextOutput;
 import com.google.android.exoplayer2.trackselection.TrackSelectionArray;
 import com.google.android.exoplayer2.trackselection.TrackSelector;
+import com.google.android.exoplayer2.util.Clock;
 import com.google.android.exoplayer2.util.Util;
 import com.google.android.exoplayer2.video.VideoRendererEventListener;
 import java.util.List;
@@ -109,8 +110,28 @@ public class SimpleExoPlayer implements ExoPlayer {
   private AudioAttributes audioAttributes;
   private float audioVolume;
 
-  protected SimpleExoPlayer(RenderersFactory renderersFactory, TrackSelector trackSelector,
-      LoadControl loadControl) {
+  /**
+   * @param renderersFactory A factory for creating {@link Renderer}s to be used by the instance.
+   * @param trackSelector The {@link TrackSelector} that will be used by the instance.
+   * @param loadControl The {@link LoadControl} that will be used by the instance.
+   */
+  protected SimpleExoPlayer(
+      RenderersFactory renderersFactory, TrackSelector trackSelector, LoadControl loadControl) {
+    this(renderersFactory, trackSelector, loadControl, Clock.DEFAULT);
+  }
+
+  /**
+   * @param renderersFactory A factory for creating {@link Renderer}s to be used by the instance.
+   * @param trackSelector The {@link TrackSelector} that will be used by the instance.
+   * @param loadControl The {@link LoadControl} that will be used by the instance.
+   * @param clock The {@link Clock} that will be used by the instance. Should always be {@link
+   *     Clock#DEFAULT}, unless the player is being used from a test.
+   */
+  protected SimpleExoPlayer(
+      RenderersFactory renderersFactory,
+      TrackSelector trackSelector,
+      LoadControl loadControl,
+      Clock clock) {
     componentListener = new ComponentListener();
     videoListeners = new CopyOnWriteArraySet<>();
     textOutputs = new CopyOnWriteArraySet<>();
@@ -129,7 +150,7 @@ public class SimpleExoPlayer implements ExoPlayer {
     videoScalingMode = C.VIDEO_SCALING_MODE_DEFAULT;
 
     // Build the player and associated objects.
-    player = createExoPlayerImpl(renderers, trackSelector, loadControl);
+    player = createExoPlayerImpl(renderers, trackSelector, loadControl, clock);
   }
 
   /**
@@ -864,11 +885,12 @@ public class SimpleExoPlayer implements ExoPlayer {
    * @param renderers The {@link Renderer}s that will be used by the instance.
    * @param trackSelector The {@link TrackSelector} that will be used by the instance.
    * @param loadControl The {@link LoadControl} that will be used by the instance.
+   * @param clock The {@link Clock} that will be used by this instance.
    * @return A new {@link ExoPlayer} instance.
    */
   protected ExoPlayer createExoPlayerImpl(
-      Renderer[] renderers, TrackSelector trackSelector, LoadControl loadControl) {
-    return new ExoPlayerImpl(renderers, trackSelector, loadControl);
+      Renderer[] renderers, TrackSelector trackSelector, LoadControl loadControl, Clock clock) {
+    return new ExoPlayerImpl(renderers, trackSelector, loadControl, clock);
   }
 
   private void removeSurfaceCallbacks() {

library/core/src/main/java/com/google/android/exoplayer2/util/HandlerWrapper.java

@@ -59,8 +59,18 @@ public interface HandlerWrapper {
   /** @see Handler#sendEmptyMessage(int). */
   boolean sendEmptyMessage(int what);
 
-  /** @see Handler#sendEmptyMessageDelayed(int, long). */
-  boolean sendEmptyMessageDelayed(int what, long delayMs);
+  /**
+   * Variant of {@code Handler#sendEmptyMessageDelayed(int, long)} which also takes a reference time
+   * measured by {@code android.os.SystemClock#elapsedRealtime()} to which the delay is added.
+   *
+   * @param what The message identifier.
+   * @param delayMs The delay in milliseconds to send the message. This delay is added to the {@code
+   *     referenceTimeMs}.
+   * @param referenceTimeMs The time which the delay is added to. Always measured with {@code
+   *     android.os.SystemClock#elapsedRealtime()}.
+   * @return Whether the message was successfully enqueued on the Handler thread.
+   */
+  boolean sendEmptyMessageDelayed(int what, long delayMs, long referenceTimeMs);
 
   /** @see Handler#removeMessages(int). */
   void removeMessages(int what);

library/core/src/main/java/com/google/android/exoplayer2/util/StandaloneMediaClock.java

@@ -32,13 +32,6 @@ public final class StandaloneMediaClock implements MediaClock {
   private PlaybackParameters playbackParameters;
 
   /**
-   * Creates a new standalone media clock.
-   */
-  public StandaloneMediaClock() {
-    this(Clock.DEFAULT);
-  }
-
-  /**
    * Creates a new standalone media clock using the given {@link Clock} implementation.
    *
    * @param clock A {@link Clock}.

library/core/src/main/java/com/google/android/exoplayer2/util/SystemHandler.java

@@ -18,6 +18,7 @@ package com.google.android.exoplayer2.util;
 import android.os.Handler.Callback;
 import android.os.Looper;
 import android.os.Message;
+import android.os.SystemClock;
 
 /** The standard implementation of {@link HandlerWrapper}. */
 /* package */ final class SystemHandler implements HandlerWrapper {
@@ -67,8 +68,14 @@ import android.os.Message;
   }
 
   @Override
-  public boolean sendEmptyMessageDelayed(int what, long delayMs) {
-    return handler.sendEmptyMessageDelayed(what, delayMs);
+  public boolean sendEmptyMessageDelayed(int what, long delayMs, long referenceTimeMs) {
+    long targetMessageTime = referenceTimeMs + delayMs;
+    long remainingDelayMs = targetMessageTime - SystemClock.elapsedRealtime();
+    if (remainingDelayMs <= 0) {
+      return handler.sendEmptyMessage(what);
+    } else {
+      return handler.sendEmptyMessageDelayed(what, remainingDelayMs);
+    }
   }
 
   @Override

testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeClock.java

@@ -177,7 +177,8 @@ public final class FakeClock implements Clock {
     }
 
     @Override
-    public boolean sendEmptyMessageDelayed(int what, long delayMs) {
+    public boolean sendEmptyMessageDelayed(int what, long delayMs, long referenceTimeMs) {
+      // Ignore referenceTimeMs measured by SystemClock and just send with requested delay.
       if (delayMs <= 0) {
         return handler.sendEmptyMessage(what);
       } else {

testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeSimpleExoPlayer.java

@@ -44,6 +44,7 @@ import com.google.android.exoplayer2.trackselection.TrackSelector;
 import com.google.android.exoplayer2.trackselection.TrackSelector.InvalidationListener;
 import com.google.android.exoplayer2.trackselection.TrackSelectorResult;
 import com.google.android.exoplayer2.util.Assertions;
+import com.google.android.exoplayer2.util.Clock;
 import java.util.Arrays;
 import java.util.concurrent.CopyOnWriteArraySet;
 
@@ -58,13 +59,13 @@ public class FakeSimpleExoPlayer extends SimpleExoPlayer {
 
   public FakeSimpleExoPlayer(RenderersFactory renderersFactory, TrackSelector trackSelector,
       LoadControl loadControl, FakeClock clock) {
-    super (renderersFactory, trackSelector, loadControl);
+    super(renderersFactory, trackSelector, loadControl, clock);
     player.setFakeClock(clock);
   }
 
   @Override
-  protected ExoPlayer createExoPlayerImpl(Renderer[] renderers, TrackSelector trackSelector,
-      LoadControl loadControl) {
+  protected ExoPlayer createExoPlayerImpl(
+      Renderer[] renderers, TrackSelector trackSelector, LoadControl loadControl, Clock clock) {
     this.player = new FakeExoPlayer(renderers, trackSelector, loadControl);
     return player;
   }