Dart 2 中与隔离物的双向通信

Posted 2023-02-23

【中文标题】Dart 2 中与隔离物的双向通信

【英文标题】：Bidirectional communication with isolates in Dart 2

【发布时间】：2019-02-15 00:17:22

【问题描述】：

我正在尝试隔离，我想知道如何让其中一些进行繁重的计算，当根隔离询问他们当前的计算值时，他们会“按需”响应。

据我所知，唯一可以用作新创建的隔离消息的对象是 SendPort，这意味着只有生成的隔离可以与根隔离。我尝试发送一个 元组，但由于 ReceivePort 不是 SendPort，它被认为是非法的。

简而言之：

root good

root 隔离如何？

【问题讨论】：

***.com/questions/29247374/… 有点过时，但应该仍然有效

【参考方案1】：

从package:stream_channel看IsolateChannel。

这应该为您尝试做的事情提供很多帮助。

【参考方案2】：

用Gunter 的comment 我做了这个：

import 'dart:async';
import 'dart:io';
import 'dart:isolate';

Stopwatch stopwatch = new Stopwatch();

main(args) async 
  ReceivePort rPort = new ReceivePort();
  rPort.listen((data) 
    print("<root> $data received");
    if (data is List) 
      String action = data[0];
      if (action == "register") 
        (data[1] as SendPort).send(stopwatch.elapsedMilliseconds);
      
    
  );
  stopwatch.start();
  await Isolate.spawn(elIsolate, rPort.sendPort);
  print("isolate spawned in $stopwatch.elapsedMilliseconds msecs"); //isolate spawned in 377 msecs


void elIsolate(SendPort sPort) 
  ReceivePort rPort = new ReceivePort();
  rPort.listen((data) 
    print("<Isolate> '$data' received"); //<Isolate> '387' received
  );
  sPort.send(["register", rPort.sendPort]);

而使用Kevin 的answer 代码简化为：

import 'dart:async';
import 'dart:io';
import 'dart:isolate';
import 'package:stream_channel/stream_channel.dart';

Stopwatch stopwatch = new Stopwatch();

main(args) async 
  ReceivePort rPort = new ReceivePort();
  IsolateChannel channel = new IsolateChannel.connectReceive(rPort);
  channel.stream.listen((data) 
    print("<root> '$data' received at $stopwatch.elapsedMilliseconds msecs"); //<root> 'hello world' received at 1141 msecs
    channel.sink.add(stopwatch.elapsedMilliseconds);
  );
  stopwatch.start();
  await Isolate.spawn(elIsolate, rPort.sendPort);
  print("isolate spawned in $stopwatch.elapsedMilliseconds msecs"); //isolate spawned in 1111 msecs


void elIsolate(SendPort sPort) 
  IsolateChannel channel = new IsolateChannel.connectSend(sPort);
  channel.stream.listen((data) 
    print("<Isolate> '$data' received");
  );
  channel.sink.add("hello world");