Report mediaPeriodCreated/Released in MaskingMediaSource.

Creating a period in MaskingMediaSource may result in delayed event reporting
depending on when the actual period gets created. To avoid event reporting
inaccuracies, report the mediaPeriodCreated and mediaPeriodReleased events
directly.

Issue:#5407
PiperOrigin-RevId: 259737170

library/core/src/main/java/com/google/android/exoplayer2/source/CompositeMediaSource.java

@@ -96,11 +96,11 @@ public abstract class CompositeMediaSource<T> extends BaseMediaSource {
   /**
    * Prepares a child source.
    *
-   * <p>{@link #onChildSourceInfoRefreshed(Object, MediaSource, Timeline)} will be called when the
-   * child source updates its timeline with the same {@code id} passed to this method.
+   * <p>{@link #onChildSourceInfoRefreshed(T, MediaSource, Timeline)} will be called when the child
+   * source updates its timeline with the same {@code id} passed to this method.
    *
-   * <p>Any child sources that aren't explicitly released with {@link #releaseChildSource(Object)}
-   * will be released in {@link #releaseSourceInternal()}.
+   * <p>Any child sources that aren't explicitly released with {@link #releaseChildSource(T)} will
+   * be released in {@link #releaseSourceInternal()}.
    *
    * @param id A unique id to identify the child source preparation. Null is allowed as an id.
    * @param mediaSource The child {@link MediaSource}.
@@ -188,6 +188,18 @@ public abstract class CompositeMediaSource<T> extends BaseMediaSource {
     return mediaTimeMs;
   }
 
+  /**
+   * Returns whether {@link MediaSourceEventListener#onMediaPeriodCreated(int, MediaPeriodId)} and
+   * {@link MediaSourceEventListener#onMediaPeriodReleased(int, MediaPeriodId)} events of the given
+   * media period should be reported. The default implementation is to always report these events.
+   *
+   * @param mediaPeriodId A {@link MediaPeriodId} in the composite media source.
+   * @return Whether create and release events for this media period should be reported.
+   */
+  protected boolean shouldDispatchCreateOrReleaseEvent(MediaPeriodId mediaPeriodId) {
+    return true;
+  }
+
   private static final class MediaSourceAndListener {
 
     public final MediaSource mediaSource;
@@ -215,16 +227,22 @@ public abstract class CompositeMediaSource<T> extends BaseMediaSource {
     @Override
     public void onMediaPeriodCreated(int windowIndex, MediaPeriodId mediaPeriodId) {
       if (maybeUpdateEventDispatcher(windowIndex, mediaPeriodId)) {
+        if (shouldDispatchCreateOrReleaseEvent(
+            Assertions.checkNotNull(eventDispatcher.mediaPeriodId))) {
           eventDispatcher.mediaPeriodCreated();
         }
       }
+    }
 
     @Override
     public void onMediaPeriodReleased(int windowIndex, MediaPeriodId mediaPeriodId) {
       if (maybeUpdateEventDispatcher(windowIndex, mediaPeriodId)) {
+        if (shouldDispatchCreateOrReleaseEvent(
+            Assertions.checkNotNull(eventDispatcher.mediaPeriodId))) {
           eventDispatcher.mediaPeriodReleased();
         }
       }
+    }
 
     @Override
     public void onLoadStarted(

library/core/src/main/java/com/google/android/exoplayer2/source/MaskingMediaSource.java

@@ -19,8 +19,10 @@ import androidx.annotation.Nullable;
 import android.util.Pair;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Timeline;
+import com.google.android.exoplayer2.source.MediaSourceEventListener.EventDispatcher;
 import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.upstream.TransferListener;
+import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import java.io.IOException;
 
@@ -37,6 +39,7 @@ public final class MaskingMediaSource extends CompositeMediaSource<Void> {
 
   private MaskingTimeline timeline;
   @Nullable private MaskingMediaPeriod unpreparedMaskingMediaPeriod;
+  @Nullable private EventDispatcher unpreparedMaskingMediaPeriodEventDispatcher;
   private boolean hasStartedPreparing;
   private boolean isPrepared;
 
@@ -96,6 +99,9 @@ public final class MaskingMediaSource extends CompositeMediaSource<Void> {
       // unset and we don't load beyond periods with unset duration. We need to figure out how to
       // handle the prepare positions of multiple deferred media periods, should that ever change.
       unpreparedMaskingMediaPeriod = mediaPeriod;
+      unpreparedMaskingMediaPeriodEventDispatcher =
+          createEventDispatcher(/* windowIndex= */ 0, id, /* mediaTimeOffsetMs= */ 0);
+      unpreparedMaskingMediaPeriodEventDispatcher.mediaPeriodCreated();
       if (!hasStartedPreparing) {
         hasStartedPreparing = true;
         prepareChildSource(/* id= */ null, mediaSource);
@@ -107,8 +113,12 @@ public final class MaskingMediaSource extends CompositeMediaSource<Void> {
   @Override
   public void releasePeriod(MediaPeriod mediaPeriod) {
     ((MaskingMediaPeriod) mediaPeriod).releasePeriod();
+    if (mediaPeriod == unpreparedMaskingMediaPeriod) {
+      Assertions.checkNotNull(unpreparedMaskingMediaPeriodEventDispatcher).mediaPeriodReleased();
+      unpreparedMaskingMediaPeriodEventDispatcher = null;
       unpreparedMaskingMediaPeriod = null;
     }
+  }
 
   @Override
   public void releaseSourceInternal() {
@@ -154,7 +164,6 @@ public final class MaskingMediaSource extends CompositeMediaSource<Void> {
       timeline = MaskingTimeline.createWithRealTimeline(newTimeline, periodUid);
       if (unpreparedMaskingMediaPeriod != null) {
         MaskingMediaPeriod maskingPeriod = unpreparedMaskingMediaPeriod;
-        unpreparedMaskingMediaPeriod = null;
         maskingPeriod.overridePreparePositionUs(periodPositionUs);
         MediaPeriodId idInSource =
             maskingPeriod.id.copyWithPeriodUid(getInternalPeriodUid(maskingPeriod.id.periodUid));
@@ -172,6 +181,14 @@ public final class MaskingMediaSource extends CompositeMediaSource<Void> {
     return mediaPeriodId.copyWithPeriodUid(getExternalPeriodUid(mediaPeriodId.periodUid));
   }
 
+  @Override
+  protected boolean shouldDispatchCreateOrReleaseEvent(MediaPeriodId mediaPeriodId) {
+    // Suppress create and release events for the period created while the source was still
+    // unprepared, as we send these events from this class.
+    return unpreparedMaskingMediaPeriod == null
+        || !mediaPeriodId.equals(unpreparedMaskingMediaPeriod.id);
+  }
+
   private Object getInternalPeriodUid(Object externalPeriodUid) {
     return externalPeriodUid.equals(MaskingTimeline.DUMMY_EXTERNAL_ID)
         ? timeline.replacedInternalId