Class TaskCompletionSource

Bolts/src/bolts/Task.java:555–640

Allows safe orchestration of a task's completion, preventing the consumer from prematurely completing the task. Essentially, it represents the producer side of a Task , providing access to the consumer side through the getTask() method while isolating the Task's completion mechanisms from th

   * mechanisms from the consumer.
   */
  public class TaskCompletionSource {
    private TaskCompletionSource() {
    }

    /**
     * @return the Task associated with this TaskCompletionSource.
     */
    public Task<TResult> getTask() {
      return Task.this;
    }

    /**
     * Sets the cancelled flag on the Task if the Task hasn't already been completed.
     */
    public boolean trySetCancelled() {
      synchronized (lock) {
        if (complete) {
          return false;
        }
        complete = true;
        cancelled = true;
        lock.notifyAll();
        runContinuations();
        return true;
      }
    }

    /**
     * Sets the result on the Task if the Task hasn't already been completed.
     */
    public boolean trySetResult(TResult result) {
      synchronized (lock) {
        if (complete) {
          return false;
        }
        complete = true;
        Task.this.result = result;
        lock.notifyAll();
        runContinuations();
        return true;
      }
    }

    /**
     * Sets the error on the Task if the Task hasn't already been completed.
     */
    public boolean trySetError(Exception error) {
      synchronized (lock) {
        if (complete) {
          return false;
        }
        complete = true;
        Task.this.error = error;
        lock.notifyAll();
        runContinuations();
        return true;
      }
    }