1 files changed, 83 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/util/ConditionVariable.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/util/ConditionVariable.java
new file mode 100644
index 0000000000..3866edced1
--- /dev/null
+++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/util/ConditionVariable.java
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.mozilla.thirdparty.com.google.android.exoplayer2.util;
+
+/**
+ * An interruptible condition variable whose {@link #open()} and {@link #close()} methods return
+ * whether they resulted in a change of state.
+ */
+public final class ConditionVariable {
+
+  private boolean isOpen;
+
+  /**
+   * Opens the condition and releases all threads that are blocked.
+   *
+   * @return True if the condition variable was opened. False if it was already open.
+   */
+  public synchronized boolean open() {
+    if (isOpen) {
+      return false;
+    }
+    isOpen = true;
+    notifyAll();
+    return true;
+  }
+
+  /**
+   * Closes the condition.
+   *
+   * @return True if the condition variable was closed. False if it was already closed.
+   */
+  public synchronized boolean close() {
+    boolean wasOpen = isOpen;
+    isOpen = false;
+    return wasOpen;
+  }
+
+  /**
+   * Blocks until the condition is opened.
+   *
+   * @throws InterruptedException If the thread is interrupted.
+   */
+  public synchronized void block() throws InterruptedException {
+    while (!isOpen) {
+      wait();
+    }
+  }
+
+  /**
+   * Blocks until the condition is opened or until {@code timeout} milliseconds have passed.
+   *
+   * @param timeout The maximum time to wait in milliseconds.
+   * @return True if the condition was opened, false if the call returns because of the timeout.
+   * @throws InterruptedException If the thread is interrupted.
+   */
+  public synchronized boolean block(long timeout) throws InterruptedException {
+    long now = android.os.SystemClock.elapsedRealtime();
+    long end = now + timeout;
+    while (!isOpen && now < end) {
+      wait(end - now);
+      now = android.os.SystemClock.elapsedRealtime();
+    }
+    return isOpen;
+  }
+
+  /** Returns whether the condition is opened. */
+  public synchronized boolean isOpen() {
+    return isOpen;
+  }
+}