* Sets the number of request credits.
     *
     * @param credits the number of credits to set
     */
    void setRequestCredits(int credits);

    /**
     * Checks if this is a cancel request.
     *
     * @return whether this is a cancel request
     */
    boolean isCancel();

    /**
     * Gets the next request in the chain.
     *
     * @return chained request
     */
    Request getNext();

    /**

  object : BufferedSocket {
    private val delegate = this@asBufferedSocket
    override val source = delegate.source.buffer()
    override val sink = delegate.sink.buffer()

    override fun cancel() {
      delegate.cancel()
    }

  fun noNewExchangesOnConnection() {
    codec.carrier.noNewExchanges()
  }

  fun cancel() {
    codec.cancel()
  }

  /**
   * Revoke this exchange's access to streams. This is necessary when a follow-up request is
   * required but the preceding exchange hasn't completed yet.
   */
  fun detachWithViolence() {
    codec.cancel()
    call.messageDone(
      exchange = this,
      requestDone = true,

Calls can be canceled from any thread. This will fail the call if it hasn’t yet completed! Code that is writing the request body or reading the response body will suffer an `IOException` when its call is canceled.

## Dispatch

// It is possible to have a disconnected client in this tiny window of time.
func CheckPortAvailability(host, port string, opts TCPOptions) (err error) {
	lc := &net.ListenConfig{}

	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()

	l, err := lc.Listen(ctx, "tcp", net.JoinHostPort(host, port))
	if err != nil {
		return err
	}

	// As we are able to listen on this network, the port is not in use.

  }

  public void testCancelled() throws Exception {
    TrustedListenableFutureTask<Integer> task = TrustedListenableFutureTask.create(returning(2));
    assertFalse(task.isDone());
    task.cancel(false);
    assertTrue(task.isDone());
    assertTrue(task.isCancelled());
    assertFalse(task.wasInterrupted());
    assertThrows(CancellationException.class, () -> getDone(task));
    verifyThreadWasNotInterrupted();

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package okhttp3.internal.http2

import java.io.IOException

/** Thrown when an HTTP/2 stream is canceled without damage to the socket that carries it. */
class StreamResetException(
  @JvmField val errorCode: ErrorCode,

  override val isReady = false

  override fun connectTcp() = result

  override fun connectTlsEtc() = result

  override fun handleSuccess() = error("unexpected call")

  override fun cancel() = error("unexpected cancel")

  override fun retry() = error("unexpected retry")

    val server = serverListener.assertOpen()

    // Initiate a close on the client, which will schedule a hard cancel in 500 ms.
    val closeAtNanos = System.nanoTime()
    webSocket.close(1000, "goodbye", 500L)
    serverListener.assertClosing(1000, "goodbye")

    // Confirm that the hard cancel occurred after 500 ms.
    clientListener.assertFailure()
    val elapsedUntilFailure = System.nanoTime() - closeAtNanos

					_ = syscall.SetsockoptString(int(fdPtr), syscall.SOL_SOCKET, syscall.SO_BINDTODEVICE, opts.Interface)
				}
			})
			return nil
		},
	}

	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()

	l, err := lc.Listen(ctx, "tcp", net.JoinHostPort(host, port))
	if err != nil {
		return err
	}

	// As we are able to listen on this network, the port is not in use.