1 files changed, 63 insertions, 0 deletions
diff --git a/third_party/libwebrtc/sdk/android/src/java/org/webrtc/RefCountDelegate.java b/third_party/libwebrtc/sdk/android/src/java/org/webrtc/RefCountDelegate.java
new file mode 100644
index 0000000000..b9210d26a4
--- /dev/null
+++ b/third_party/libwebrtc/sdk/android/src/java/org/webrtc/RefCountDelegate.java
@@ -0,0 +1,63 @@
+/*
+ *  Copyright 2018 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+package org.webrtc;
+
+import androidx.annotation.Nullable;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Implementation of RefCounted that executes a Runnable once the ref count reaches zero.
+ */
+class RefCountDelegate implements RefCounted {
+  private final AtomicInteger refCount = new AtomicInteger(1);
+  private final @Nullable Runnable releaseCallback;
+
+  /**
+   * @param releaseCallback Callback that will be executed once the ref count reaches zero.
+   */
+  public RefCountDelegate(@Nullable Runnable releaseCallback) {
+    this.releaseCallback = releaseCallback;
+  }
+
+  @Override
+  public void retain() {
+    int updated_count = refCount.incrementAndGet();
+    if (updated_count < 2) {
+      throw new IllegalStateException("retain() called on an object with refcount < 1");
+    }
+  }
+
+  @Override
+  public void release() {
+    int updated_count = refCount.decrementAndGet();
+    if (updated_count < 0) {
+      throw new IllegalStateException("release() called on an object with refcount < 1");
+    }
+    if (updated_count == 0 && releaseCallback != null) {
+      releaseCallback.run();
+    }
+  }
+
+  /**
+   * Tries to retain the object. Can be used in scenarios where it is unknown if the object has
+   * already been released. Returns true if successful or false if the object was already released.
+   */
+  boolean safeRetain() {
+    int currentRefCount = refCount.get();
+    while (currentRefCount != 0) {
+      if (refCount.weakCompareAndSet(currentRefCount, currentRefCount + 1)) {
+        return true;
+      }
+      currentRefCount = refCount.get();
+    }
+    return false;
+  }
+}