飞镖/颤振:隔离的顶级功能的异步行为 [英] Dart / Flutter: async behaviour of an Isolate's top level function

问题描述

是的，好的人， 我遇到了奇怪的行为

Aye Aye good people, I'm experiencing a weird behavior

异步使用隔离的顶级功能时；

when using the top level function of an isolate asynchronously;

您可以找到示例代码这里，但总之

you can find example code HERE, but in short

作为隔离的顶级功能:

String _syncHandle(int data) {
  return 'done';
}

这不是:

Future<String> _syncHandle(int data) async {
  return 'done';
}

有人能解释我为什么吗?

can anybody explain me why?

(或者，如果应该工作，为什么在我的代码中不这样做?)

(or if should work, why isn't doing so in my code?)

先谢谢您

弗朗切斯科

...

[edit:刚刚注意到有人问过类似的问题，

[edit: just noticed that a similar question has been asked,

尽管如此，它仍然没有答案 从隔离函数中调用异步函数，

nevertheless it is still unanswered Call async function from Isolate function,

在 github ]

推荐答案

忘记更新此:/ 如果您查看问题中链接的代码

forgot to update this :/ if you look at the code linked in the question

isolates_logging/lib/provider/test_isolate.dart

isolates_logging/lib/provider/test_isolate.dart

  Future<void> _handle(int _m) async {
    final response = ReceivePort();
    isolateTest = await Isolate.spawn(_isolate, response.sendPort);
    final sendPort = await response.first as SendPort;
    final answer = ReceivePort();
    sendPort.send([_m, answer.sendPort]);
    await answer.first.then((p) { 
      _outbound.sink.add(p);});
  }

  static void _isolate(SendPort _initialReplyTo) {
    final port =  ReceivePort();
    _initialReplyTo.send(port.sendPort);
    port.listen((message) {
      final data = message[0] as int;
      final send = message[1] as SendPort;
      send.send(_syncHandle(data));
    });
  }
}

Future<String> _syncHandle(int data) async {
  return 'done';
}

注意send.send(_syncHandle(data));部分

note the send.send(_syncHandle(data)); part

如果这样做，则只能发送基元，而不能发送期货， 基本上就是这样

if you do so, you can send only primitives and not futures, basically that's it

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