From 3480a27994ef9e06bd7574bad4656eb8c7677971 Mon Sep 17 00:00:00 2001
From: ibaker <ibaker@google.com>
Date: Fri, 31 Mar 2023 09:56:59 +0100
Subject: [PATCH] Add warning logs if `DefaultDrmSessionManager` is used on
 wrong thread

Issue: google/ExoPlayer#11008
PiperOrigin-RevId: 520864579
(cherry picked from commit 7ca966842185dd6f07563f28058d78537b916731)
---
 .../exoplayer/drm/DefaultDrmSession.java      | 31 +++++++++++++++++--
 .../drm/DefaultDrmSessionManager.java         | 22 +++++++++++++
 2 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/drm/DefaultDrmSession.java b/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/drm/DefaultDrmSession.java
index c64eb57dabc..b04c5b1cd88 100644
--- a/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/drm/DefaultDrmSession.java
+++ b/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/drm/DefaultDrmSession.java
@@ -136,9 +136,10 @@ public interface ReferenceCountListener {
   private final LoadErrorHandlingPolicy loadErrorHandlingPolicy;
   private final PlayerId playerId;
 
-  /* package */ final MediaDrmCallback callback;
-  /* package */ final UUID uuid;
-  /* package */ final ResponseHandler responseHandler;
+  private final MediaDrmCallback callback;
+  private final UUID uuid;
+  private final Looper playbackLooper;
+  private final ResponseHandler responseHandler;
 
   private @DrmSession.State int state;
   private int referenceCount;
@@ -209,10 +210,12 @@ public DefaultDrmSession(
     this.loadErrorHandlingPolicy = loadErrorHandlingPolicy;
     this.playerId = playerId;
     state = STATE_OPENING;
+    this.playbackLooper = playbackLooper;
     responseHandler = new ResponseHandler(playbackLooper);
   }
 
   public boolean hasSessionId(byte[] sessionId) {
+    verifyPlaybackThread();
     return Arrays.equals(this.sessionId, sessionId);
   }
 
@@ -255,50 +258,59 @@ public void onProvisionError(Exception error, boolean thrownByExoMediaDrm) {
 
   @Override
   public final @DrmSession.State int getState() {
+    verifyPlaybackThread();
     return state;
   }
 
   @Override
   public boolean playClearSamplesWithoutKeys() {
+    verifyPlaybackThread();
     return playClearSamplesWithoutKeys;
   }
 
   @Override
   @Nullable
   public final DrmSessionException getError() {
+    verifyPlaybackThread();
     return state == STATE_ERROR ? lastException : null;
   }
 
   @Override
   public final UUID getSchemeUuid() {
+    verifyPlaybackThread();
     return uuid;
   }
 
   @Override
   @Nullable
   public final CryptoConfig getCryptoConfig() {
+    verifyPlaybackThread();
     return cryptoConfig;
   }
 
   @Override
   @Nullable
   public Map<String, String> queryKeyStatus() {
+    verifyPlaybackThread();
     return sessionId == null ? null : mediaDrm.queryKeyStatus(sessionId);
   }
 
   @Override
   @Nullable
   public byte[] getOfflineLicenseKeySetId() {
+    verifyPlaybackThread();
     return offlineLicenseKeySetId;
   }
 
   @Override
   public boolean requiresSecureDecoder(String mimeType) {
+    verifyPlaybackThread();
     return mediaDrm.requiresSecureDecoder(checkStateNotNull(sessionId), mimeType);
   }
 
   @Override
   public void acquire(@Nullable DrmSessionEventListener.EventDispatcher eventDispatcher) {
+    verifyPlaybackThread();
     if (referenceCount < 0) {
       Log.e(TAG, "Session reference count less than zero: " + referenceCount);
       referenceCount = 0;
@@ -326,6 +338,7 @@ && isOpen()
 
   @Override
   public void release(@Nullable DrmSessionEventListener.EventDispatcher eventDispatcher) {
+    verifyPlaybackThread();
     if (referenceCount <= 0) {
       Log.e(TAG, "release() called on a session that's already fully released.");
       return;
@@ -561,6 +574,18 @@ private void dispatchEvent(Consumer<DrmSessionEventListener.EventDispatcher> eve
     }
   }
 
+  private void verifyPlaybackThread() {
+    if (Thread.currentThread() != playbackLooper.getThread()) {
+      Log.w(
+          TAG,
+          "DefaultDrmSession accessed on the wrong thread.\nCurrent thread: "
+              + Thread.currentThread().getName()
+              + "\nExpected thread: "
+              + playbackLooper.getThread().getName(),
+          new IllegalStateException());
+    }
+  }
+
   // Internal classes.
 
   @SuppressLint("HandlerLeak")
diff --git a/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/drm/DefaultDrmSessionManager.java b/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/drm/DefaultDrmSessionManager.java
index 9a345ffff73..05ab52a0395 100644
--- a/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/drm/DefaultDrmSessionManager.java
+++ b/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/drm/DefaultDrmSessionManager.java
@@ -471,6 +471,7 @@ public void setMode(@Mode int mode, @Nullable byte[] offlineLicenseKeySetId) {
 
   @Override
   public final void prepare() {
+    verifyPlaybackThread(/* allowBeforeSetPlayer= */ true);
     if (prepareCallsCount++ != 0) {
       return;
     }
@@ -487,6 +488,7 @@ public final void prepare() {
 
   @Override
   public final void release() {
+    verifyPlaybackThread(/* allowBeforeSetPlayer= */ true);
     if (--prepareCallsCount != 0) {
       return;
     }
@@ -513,6 +515,7 @@ public void setPlayer(Looper playbackLooper, PlayerId playerId) {
   @Override
   public DrmSessionReference preacquireSession(
       @Nullable DrmSessionEventListener.EventDispatcher eventDispatcher, Format format) {
+    // Don't verify the playback thread, preacquireSession can be called from any thread.
     checkState(prepareCallsCount > 0);
     checkStateNotNull(playbackLooper);
     PreacquiredSessionReference preacquiredSessionReference =
@@ -525,6 +528,7 @@ public DrmSessionReference preacquireSession(
   @Nullable
   public DrmSession acquireSession(
       @Nullable DrmSessionEventListener.EventDispatcher eventDispatcher, Format format) {
+    verifyPlaybackThread(/* allowBeforeSetPlayer= */ false);
     checkState(prepareCallsCount > 0);
     checkStateNotNull(playbackLooper);
     return acquireSession(
@@ -599,6 +603,7 @@ private DrmSession acquireSession(
 
   @Override
   public @C.CryptoType int getCryptoType(Format format) {
+    verifyPlaybackThread(/* allowBeforeSetPlayer= */ false);
     @C.CryptoType int cryptoType = checkNotNull(exoMediaDrm).getCryptoType();
     if (format.drmInitData == null) {
       int trackType = MimeTypes.getTrackType(format.sampleMimeType);
@@ -817,6 +822,23 @@ private void maybeReleaseMediaDrm() {
     }
   }
 
+  private void verifyPlaybackThread(boolean allowBeforeSetPlayer) {
+    if (allowBeforeSetPlayer && playbackLooper == null) {
+      Log.w(
+          TAG,
+          "DefaultDrmSessionManager accessed before setPlayer(), possibly on the wrong thread.",
+          new IllegalStateException());
+    } else if (Thread.currentThread() != checkNotNull(playbackLooper).getThread()) {
+      Log.w(
+          TAG,
+          "DefaultDrmSessionManager accessed on the wrong thread.\nCurrent thread: "
+              + Thread.currentThread().getName()
+              + "\nExpected thread: "
+              + playbackLooper.getThread().getName(),
+          new IllegalStateException());
+    }
+  }
+
   /**
    * Extracts {@link SchemeData} instances suitable for the given DRM scheme {@link UUID}.
    *