我正在尝试在Dart中编写一个HTTP服务器,该服务器可以并行处理多个请求。到目前为止,我未能成功实现“并行”部分。
这是我最初尝试的内容:
import 'dart:io';
main() {
HttpServer.bind(InternetAddress.ANY_IP_V4, 8080).then((HttpServer server) {
server.listen((HttpRequest request) {
Stopwatch stopwatch = new Stopwatch();
stopwatch.start();
while (stopwatch.elapsedMilliseconds < 1000) { /* do nothing */ }
request.response.statusCode = HttpStatus.OK;
request.response.write(stopwatch.elapsedMilliseconds.toString());
request.response.close().catchError(print);
});
});
}
对于每个请求,它都会忙一秒钟,然后完成。我以这种方式处理请求,以便可以预测其时间安排,因此我可以轻松地在Windows任务管理器中看到请求的效果(CPU核心使用率达到100%)。
我可以说这不是并行处理请求,因为:
http://example:8080/
,然后全部刷新,则这些选项卡将依次依次加载,每个之间的间隔约为1秒。 wrk -d 10 -c 8 -t 8 http://example:8080/
...,它将在我给出的10秒钟内完成5至8个请求。如果服务器使用了我所有的8个内核,那么我希望有接近80个请求的数字。 因此,然后我尝试使用隔离,希望为每个请求手动产生一个新的隔离/线程:
import 'dart:io';
import 'dart:isolate';
main() {
HttpServer.bind(InternetAddress.ANY_IP_V4, 8080).then((HttpServer server) {
server.listen((HttpRequest request) {
spawnFunction(handleRequest).send(request);
});
});
}
handleRequest() {
port.receive((HttpRequest request, SendPort sender) {
Stopwatch stopwatch = new Stopwatch();
stopwatch.start();
while (stopwatch.elapsedMilliseconds < 1000) { /* do nothing */ }
request.response.statusCode = HttpStatus.OK;
request.response.write(stopwatch.elapsedMilliseconds.toString());
request.response.close().catchError(print);
});
}
这根本不起作用。它不喜欢我尝试将HttpRequest作为消息发送到隔离区。这是错误:
#0 _SendPortImpl._sendInternal (dart:isolate-patch/isolate_patch.dart:122:3)
#1 _SendPortImpl._sendNow (dart:isolate-patch/isolate_patch.dart:95:18)
#2 _SendPortImpl.send (dart:isolate-patch/isolate_patch.dart:91:18)
#3 main.<anonymous closure>.<anonymous closure> (file:///C:/Development/dartbenchmark/simple2.dart:7:40)
#4 _StreamSubscriptionImpl._sendData (dart:async/stream_impl.dart:475:12)
#5 _StreamImpl._sendData.<anonymous closure> (dart:async/stream_impl.dart:251:29)
#6 _SingleStreamImpl._forEachSubscriber (dart:async/stream_impl.dart:335:11)
#7 _StreamImpl._sendData (dart:async/stream_impl.dart:249:23)
#8 _StreamImpl._add (dart:async/stream_impl.dart:51:16)
#9 StreamController.add (dart:async/stream_controller.dart:10:35)
#10 _HttpServer._handleRequest (http_impl.dart:1261:20)
#11 _HttpConnection._HttpConnection.<anonymous closure> (http_impl.dart:1188:33)
#12 _StreamSubscriptionImpl._sendData (dart:async/stream_impl.dart:475:12)
#13 _StreamImpl._sendData.<anonymous closure> (dart:async/stream_impl.dart:251:29)
#14 _SingleStreamImpl._forEachSubscriber (dart:async/stream_impl.dart:335:11)
#15 _StreamImpl._sendData (dart:async/stream_impl.dart:249:23)
#16 _StreamImpl._add (dart:async/stream_impl.dart:51:16)
#17 StreamController.add (dart:async/stream_controller.dart:10:35)
#18 _HttpParser._doParse (http_parser.dart:415:26)
#19 _HttpParser._parse (http_parser.dart:161:15)
#20 _HttpParser._onData._onData (http_parser.dart:509:11)
#21 _StreamSubscriptionImpl._sendData (dart:async/stream_impl.dart:475:12)
#22 _StreamImpl._sendData.<anonymous closure> (dart:async/stream_impl.dart:251:29)
#23 _SingleStreamImpl._forEachSubscriber (dart:async/stream_impl.dart:335:11)
#24 _StreamImpl._sendData (dart:async/stream_impl.dart:249:23)
#25 _StreamImpl._add (dart:async/stream_impl.dart:51:16)
#26 StreamController.add (dart:async/stream_controller.dart:10:35)
#27 _Socket._onData._onData (dart:io-patch/socket_patch.dart:726:42)
#28 _StreamSubscriptionImpl._sendData (dart:async/stream_impl.dart:475:12)
#29 _StreamImpl._sendData.<anonymous closure> (dart:async/stream_impl.dart:251:29)
#30 _SingleStreamImpl._forEachSubscriber (dart:async/stream_impl.dart:335:11)
#31 _StreamImpl._sendData (dart:async/stream_impl.dart:249:23)
#32 _StreamImpl._add (dart:async/stream_impl.dart:51:16)
#33 StreamController.add (dart:async/stream_controller.dart:10:35)
#34 _RawSocket._RawSocket.<anonymous closure> (dart:io-patch/socket_patch.dart:452:52)
#35 _NativeSocket.multiplex (dart:io-patch/socket_patch.dart:253:18)
#36 _NativeSocket.connectToEventHandler.<anonymous closure> (dart:io-patch/socket_patch.dart:338:54)
#37 _ReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:81:92)
Unhandled exception:
Illegal argument(s): Illegal argument in isolate message : (object is a closure)
#0 _throwDelayed.<anonymous closure> (dart:async/stream_impl.dart:22:5)
#1 _asyncRunCallback._asyncRunCallback (dart:async/event_loop.dart:15:17)
#2 _asyncRunCallback._asyncRunCallback (dart:async/event_loop.dart:25:9)
#3 Timer.run.<anonymous closure> (dart:async/timer.dart:17:21)
#4 Timer.run.<anonymous closure> (dart:async/timer.dart:25:13)
#5 Timer.Timer.<anonymous closure> (dart:async-patch/timer_patch.dart:9:15)
#6 _Timer._createTimerHandler._handleTimeout (timer_impl.dart:99:28)
#7 _Timer._createTimerHandler._handleTimeout (timer_impl.dart:107:7)
#8 _Timer._createTimerHandler.<anonymous closure> (timer_impl.dart:115:23)
#9 _ReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:81:92)
使用的版本:
是否可以使用Dart使用我的机器所有可用内核并行处理这些请求?
最佳答案
我写了一个叫做dart-isoserver的库来做这个。现在已经严重烂掉了,但是您可以看到这种方法。
https://code.google.com/p/dart-isoserver/
我所做的是通过隔离端口代理HttpRequest和HttpResponse,因为您无法直接发送它们。尽管有一些警告,但它仍然有效:
请求和响应上的
spawnFunction()
现在具有一个未捕获的异常处理程序参数,因此这是可以修复的,但是spawnUri()没有。 dart-isoserver使用spawnUri()来实现热加载,因此必须将其删除。 关于第一个代码示例的注释。正如您所注意到的,那肯定不会并行运行,因为Dart是单线程的。同一隔离中的Dart代码永远不会同时运行。
关于dart - Dart:并行处理传入的HTTP请求,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/16703631/