From 3f24d4433ae36004672567b8d22cfb0f88fa4c96 Mon Sep 17 00:00:00 2001
From: aquilescanta <aquilescanta@google.com>
Date: Thu, 11 Jul 2019 11:33:38 +0100
Subject: [PATCH] Optimize DrmSession reference replacement

Potentially avoids up to two calls to synchronized methods

PiperOrigin-RevId: 257578304
---
 .../java/com/google/android/exoplayer2/drm/DrmSession.java | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/library/core/src/main/java/com/google/android/exoplayer2/drm/DrmSession.java b/library/core/src/main/java/com/google/android/exoplayer2/drm/DrmSession.java
index df45323ca3..722ab946f0 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/drm/DrmSession.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/drm/DrmSession.java
@@ -31,10 +31,15 @@ public interface DrmSession<T extends ExoMediaCrypto> {
 
   /**
    * Invokes {@code newSession's} {@link #acquireReference()} and {@code previousSession's} {@link
-   * #releaseReference()} in that order. Does nothing for passed null values.
+   * #releaseReference()} in that order. Null arguments are ignored. Does nothing if {@code
+   * previousSession} and {@code newSession} are the same session.
    */
   static <T extends ExoMediaCrypto> void replaceSessionReferences(
       @Nullable DrmSession<T> previousSession, @Nullable DrmSession<T> newSession) {
+    if (previousSession == newSession) {
+      // Do nothing.
+      return;
+    }
     if (newSession != null) {
       newSession.acquireReference();
     }