// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS
// file for details. All rights reserved. Use of this source code is governed
// by a BSD-style license that can be found in the LICENSE file.

/// @assertion void ping(
///      SendPort responsePort, {
///      Object response,
///      int priority: IMMEDIATE
/// })
///    Request that the isolate send response on the responsePort.
///    If the isolate is alive, it will eventually send response (defaulting
/// to null) on the response port.
///    The priority must be one of IMMEDIATE or BEFORE_NEXT_EVENT. The response
/// is sent at different times depending on the ping type:
///    * IMMEDIATE: The isolate responds as soon as it receives the control
/// message. This is after any previous control message from the same isolate
/// has been received, but may be during execution of another event.
///    * BEFORE_NEXT_EVENT: The response is scheduled for the next time control
/// returns to the event loop of the receiving isolate, after the current event,
/// and any already scheduled control events, are completed.
///    If response cannot be sent to the isolate, then the request is ignored.
/// It is recommended to only use simple values that can be sent to all isolates,
/// like null, booleans, numbers or strings.
///
/// @description Check that isolate sends response null after ping() call with
/// given response port and priority IMMEDIATE. The isolate is continuously
/// running.
///
/// @author a.semenov@unipro.ru

import "dart:isolate";
import "dart:math";
import "../../../Utils/expect.dart";

entryPoint(message){
  Random random = new Random();
  int s = 0;
  while (true){
    s = -s + random.nextInt(100);
  }
}

test() async {
  ReceivePort onExit = new ReceivePort();
  Isolate isolate = await Isolate.spawn(
      entryPoint,
      null, // message
      onExit:onExit.sendPort,
      errorsAreFatal:true
  );
  // check
  ReceivePort pingPort = new ReceivePort();
  isolate.ping(pingPort.sendPort, priority:Isolate.immediate);
  Expect.isNull(await pingPort.first);
  // clean up
  isolate.kill(priority:Isolate.immediate);
  await onExit.first;
  asyncEnd();
}

main() {
  asyncStart();
  test();
}