blob: 4901c550296dc8d09370947eb41451d102caf774 [file] [log] [blame]
// Copyright (c) 2020, 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.
// Sample showing how to do async callbacks by telling the Dart isolate to
// yields its execution thread to C so it can perform the callbacks on the
// main Dart thread.
// TODO( Update this when we get real async callbacks.
import 'dart:ffi';
import 'dart:isolate';
import 'package:expect/expect.dart';
import '../dylib_utils.dart';
int globalResult = 0;
int numCallbacks1 = 0;
int numCallbacks2 = 0;
main() async {
print("Dart = Dart mutator thread executing Dart.");
print("C Da = Dart mutator thread executing C.");
print("C T1 = Some C thread executing C.");
print("C T2 = Some C thread executing C.");
print("C = C T1 or C T2.");
print("Dart: Setup.");
Expect.isTrue(NativeApi.majorVersion == 2);
Expect.isTrue(NativeApi.minorVersion >= 0);
final initializeApi = dl.lookupFunction<IntPtr Function(Pointer<Void>),
int Function(Pointer<Void>)>("InitDartApiDL");
Expect.isTrue(initializeApi(NativeApi.initializeApiDLData) == 0);
final interactiveCppRequests = ReceivePort()..listen(requestExecuteCallback);
final int nativePort = interactiveCppRequests.sendPort.nativePort;
registerCallback1(nativePort, callback1FP);
registerCallback2(nativePort, callback2FP);
print("Dart: Tell C to start worker threads.");
// We need to yield control in order to be able to receive messages.
while (numCallbacks2 < 3) {
print("Dart: Yielding (able to receive messages on port).");
await asyncSleep(500);
print("Dart: Received expected number of callbacks.");
Expect.equals(2, numCallbacks1);
Expect.equals(3, numCallbacks2);
Expect.equals(14, globalResult);
print("Dart: Tell C to stop worker threads.");
print("Dart: Done.");
int callback1(int a) {
print("Dart: callback1($a).");
return a + 3;
void callback2(int a) {
print("Dart: callback2($a).");
globalResult += a;
void requestExecuteCallback(dynamic message) {
final int work_address = message;
final work = Pointer<Work>.fromAddress(work_address);
print("Dart: Calling into C to execute callback ($work).");
print("Dart: Done with callback.");
final callback1FP = Pointer.fromFunction<IntPtr Function(IntPtr)>(callback1, 0);
final callback2FP = Pointer.fromFunction<Void Function(IntPtr)>(callback2);
final dl = dlopenPlatformSpecific("ffi_test_functions");
final registerCallback1 = dl.lookupFunction<
Void Function(Int64 sendPort,
Pointer<NativeFunction<IntPtr Function(IntPtr)>> functionPointer),
void Function(int sendPort,
Pointer<NativeFunction<IntPtr Function(IntPtr)>> functionPointer)>(
final registerCallback2 = dl.lookupFunction<
Void Function(Int64 sendPort,
Pointer<NativeFunction<Void Function(IntPtr)>> functionPointer),
void Function(int sendPort,
Pointer<NativeFunction<Void Function(IntPtr)>> functionPointer)>(
final startWorkSimulator =
dl.lookupFunction<Void Function(), void Function()>('StartWorkSimulator');
final stopWorkSimulator =
dl.lookupFunction<Void Function(), void Function()>('StopWorkSimulator');
final executeCallback = dl.lookupFunction<Void Function(Pointer<Work>),
void Function(Pointer<Work>)>('ExecuteCallback');
class Work extends Opaque {}
Future asyncSleep(int ms) {
return new Future.delayed(Duration(milliseconds: ms));