* See the License for the specific language governing permissions and
 * limitations under the License.
 */
package okhttp3

import okio.ByteString

/**
 * A non-blocking interface to a web socket. Use the [factory][WebSocket.Factory] to create
 * instances; usually this is [OkHttpClient].
 *
 * ## Web Socket Lifecycle
 *

   *
   * <p>Currently, this method is invoked while holding a lock. If an implementation of this method
   * blocks, it can prevent this service from changing state. If you need to performing a blocking
   * operation in order to trigger shutdown, consider instead registering a listener and
   * implementing {@code stopping}. Note, however, that {@code stopping} does not run at exactly the

   * Drains the queue as {@link BlockingQueue#drainTo(Collection, int)}, but if the requested {@code
   * numElements} elements are not available, it will wait for them up to the specified timeout.
   *
   * @param q the blocking queue to be drained
   * @param buffer where to add the transferred elements
   * @param numElements the number of elements to be waited for
   * @param timeout how long to wait before giving up, in units of {@code unit}

    // thread because the task will block on the task latch after unblocking
    // the run latch.
    exec.execute(task);
    runLatch.await();
    assertEquals(1, listenerLatch.getCount());
    assertFalse(task.isDone());
    assertFalse(task.isCancelled());

    // Finish the task by unblocking the task latch.  Then wait for the
    // listener to be called by blocking on the listener latch.
    taskLatch.countDown();

import java.util.concurrent.TimeUnit;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An unbounded {@linkplain BlockingQueue blocking queue} that uses the same ordering rules as class
 * {@link PriorityQueue} and supplies blocking retrieval operations. While this queue is logically
 * unbounded, attempted additions may fail due to resource exhaustion (causing {@code

import java.util.NoSuchElementException;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.TimeUnit;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A bounded {@linkplain BlockingQueue blocking queue} backed by an array. This queue orders
 * elements FIFO (first-in-first-out). The head of the queue is that element that has been

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.io.Serializable;
import java.util.ArrayDeque;
import java.util.Collection;
import java.util.Queue;

/**
 * A non-blocking queue which automatically evicts elements from the head of the queue when
 * attempting to add new elements onto the queue and it is full. This queue orders elements FIFO

    }
    final CyclicBarrier barrier =
        new CyclicBarrier(
            6 // for the setter threads
                + 50 // for the listeners
                + 50 // for the blocking get threads,
                + 1); // for the main thread
    final ExecutorService executor = Executors.newFixedThreadPool(barrier.getParties());

     *   available.
     * 3. We expect the client's get() to throw an InterruptedException.
     * 4. We expect the client thread's interrupt state to be false.
     * 5. The client thread again makes a blocking call to get().
     * 6. Now the result becomes available.
     * 7. We expect get() to return this result.
     * 8. We expect the test thread's interrupt state to be false.
     */

  // Internal state of this connection is guarded by 'lock'. No blocking operations may be
  // performed while holding this lock!
  //
  // Socket writes are guarded by frameWriter.
  //
  // Socket reads are unguarded but are only made by the reader thread.
  //
  // Certain operations (like SYN_STREAM) need to synchronize on both the frameWriter (to do