注册top域名做公司网站,网站标题怎么设置,应用软件开发过程,新郑网站建设公司上篇讲到.net core web app是如何启动并接受请求的#xff0c;下面接着探索kestrel server是如何完成此任务的。 1.kestrel server的入口KestrelServer.Start (Microsoft.AspNetCore.Hosting.Server.IHttpApplication ) FrameFactory创建的frame实例最终会交给libuv的loop回调… 上篇讲到.net core web app是如何启动并接受请求的下面接着探索kestrel server是如何完成此任务的。 1.kestrel server的入口KestrelServer.Start (Microsoft.AspNetCore.Hosting.Server.IHttpApplication ) FrameFactory创建的frame实例最终会交给libuv的loop回调接收请求。但是在这过程中还是有很多的初始化工作需要做的。后面我们就管中窥豹来看一看。 public void StartTContext(IHttpApplicationTContext application)
{ var engine new KestrelEngine(new ServiceContext{FrameFactory context { return new FrameTContext(application, context);},AppLifetime _applicationLifetime,Log trace,ThreadPool new LoggingThreadPool(trace),DateHeaderValueManager dateHeaderValueManager,ServerOptions Options}); //启动引擎。完成libuv的配置和启动engine.Start(threadCount); //针对绑定的多个地址创建server来接收请求。也就是针对ip:port来启动tcp监听foreach (var address in _serverAddresses.Addresses.ToArray()){engine.CreateServer(ipv4Address);}
} 2.启动kestrel engine。engine.Start(threadCount); 启动绑定的端口*最大处理线程的thread。并初始化libuv组件。每一个线程初始化libuv注册loop回调等并启动libuv。 public void Start(int count){ for (var index 0; index count; index){Threads.Add(new KestrelThread(this));} foreach (var thread in Threads){thread.StartAsync().Wait();}
}private void ThreadStart(object parameter){ lock (_startSync){ var tcs (TaskCompletionSourceint) parameter; try{ //初始化loop_loop.Init(_engine.Libuv); //注册loop回调//EnqueueCloseHandle持有的资源释放后的回调方法回调往queue内增加一个item事件循环该queue完成资源的最终释放_post.Init(_loop, OnPost, EnqueueCloseHandle); //注册心跳定时器_heartbeatTimer.Init(_loop, EnqueueCloseHandle); //启动心跳定时器_heartbeatTimer.Start(OnHeartbeat, timeout: HeartbeatMilliseconds, repeat: HeartbeatMilliseconds);_initCompleted true;tcs.SetResult(0);} catch (Exception ex){tcs.SetException(ex); return;}} try{ //当前线程执行到Run()这里会挂起_loop.Run(); //应用程序stopshutdown之类的情况libuv唤醒当前线程完成资源清理if (_stopImmediate){ // thread-abort form of exit, resources will be leaked//线程中止形式的退出资源会被泄露。return;} // run the loop one more time to delete the open handles//再次运行循环以删除打开的句柄_post.Reference();_post.Dispose();_heartbeatTimer.Dispose(); // Ensure the Dispose operations complete in the event loop.//确保事件循环中的Dispose操作完成。_loop.Run();_loop.Dispose();} catch (Exception ex){_closeError ExceptionDispatchInfo.Capture(ex); // Request shutdown so we can rethrow this exception// in Stop which should be observable.//请求关闭以便我们可以重新抛出此异常在停止应该是可观察的。_appLifetime.StopApplication();} finally{_threadTcs.SetResult(null);}
} 3.libuv启动完成之后接着就是处理订阅注册tcp了。 回到1的kestrel的start中。接着执行engine.CreateServer(ipv4Address);这里和.net 里面的tcplistener不太一样。.net里面就是listener bindstartaccept就好了。而libuv涉及到一个多路io复用的概念这也是为什么使用他能高并发的原因。 public IDisposable CreateServer(ServerAddress address){ var usingPipes address.IsUnixPipe; var pipeName (Libuv.IsWindows ? \\.\pipe\kestrel_ : /tmp/kestrel_) Guid.NewGuid().ToString(n); var single Threads.Count 1; var first true; foreach (var thread in Threads){ if(single){}//single就不考虑这种情况真是环境是不会这样玩的else if (first) { //根据当前平台创建tcp listenervar listener usingPipes? (ListenerPrimary)new PipeListenerPrimary(ServiceContext): new TcpListenerPrimary(ServiceContext);listener.StartAsync(pipeName, address, thread).Wait();} else{ //如果是多次对同一个ip:port做监听var listener usingPipes? (ListenerSecondary)new PipeListenerSecondary(ServiceContext): new TcpListenerSecondary(ServiceContext);listener.StartAsync(pipeName, address, thread).Wait();}first false;}
} tcplistener启动细节这里就只看TcpListenerPrimary了。 首先说明一下TcpListenerPrimary这个类的继承关系TcpListenerPrimary --ListenerPrimary --Listener。这样才有助于后续代码的理解。后续代码到处都能看到thread.post/postaysnc的代码。这玩意的意思是把传入的action放到libuv loop中并激活异步完成回调。libuv另一个重要的概念各种回调。1.接着上面的代码我们进入TcpListenerPrimary.StartAsync()方法。方法在ListenerPrimary中。 public async Task StartAsync(string pipeName, ServerAddress address, KestrelThread thread){_pipeName pipeName; await StartAsync(address, thread).ConfigureAwait(false); await Thread.PostAsync(state ((ListenerPrimary)state).PostCallback(), this).ConfigureAwait(false);
} 2.接着上面的代码进入StartAsync(address, thread)。他是父类Listener的方法。 public Task StartAsync(ServerAddress address, KestrelThread thread){ServerAddress address; Thread thread; var tcs new TaskCompletionSourceint(this);Thread.Post(state { var tcs2 (TaskCompletionSourceint)state; var listener ((Listener)tcs2.Task.AsyncState); //创建socketlistener.ListenSocket listener.CreateListenSocket(); ////socket监听libu注册监听并设置回调函数最大队列。ListenSocket.Listen(Constants.ListenBacklog, ConnectionCallback, this);tcs2.SetResult(0);}, tcs); return tcs.Task;
}protected override UvStreamHandle CreateListenSocket(){ //初始化socket并bind到addressvar socket new UvTcpHandle(Log);socket.Init(Thread.Loop, Thread.QueueCloseHandle); //是否使用Nagles algorithm算法。socket.NoDelay(ServerOptions.NoDelay);socket.Bind(ServerAddress); // If requested port was 0, replace with assigned dynamic port.ServerAddress.Port socket.GetSockIPEndPoint().Port; return socket;
} 在接着上面的代码ListenSocket.Listen成功之后libuv回调ConnectionCallback函数。 进入ConnectionCallback函数完成重要的listen Accept. step1:listen成功libuv回调ConnectionCallback方法。step2初始化接收请求socket并将之关联到监听socketstep3:适配接收请求socket如果是第一次适配的话则创建connectionstep4:创建connection并启动step5:new connection 关联 Frame 对象。 step6:启动frame step7:由Connection类调用一次以开始RequestProcessingAsync循环。 step8:循环接收请求接收请求到之后交给上层程序处理 private static void ConnectionCallback(UvStreamHandle stream, int status, Exception error, object state){ var listener (Listener)state;listener.OnConnection(stream, status);//step 1}protected override void OnConnection(UvStreamHandle listenSocket, int status)//step 2{ var acceptSocket new UvTcpHandle(Log);acceptSocket.Init(Thread.Loop, Thread.QueueCloseHandle);acceptSocket.NoDelay(ServerOptions.NoDelay);listenSocket.Accept(acceptSocket);DispatchConnection(acceptSocket);
}protected override void DispatchConnection(UvStreamHandle socket)// step 3{ var index _dispatchIndex % (_dispatchPipes.Count 1); if (index _dispatchPipes.Count){ base.DispatchConnection(socket);} else{DetachFromIOCP(socket); var dispatchPipe _dispatchPipes[index]; var write new UvWriteReq(Log);write.Init(Thread.Loop);write.Write2(dispatchPipe, _dummyMessage, socket,(write2, status, error, state) {write2.Dispose();((UvStreamHandle)state).Dispose();},socket);}
} protected virtual void DispatchConnection(UvStreamHandle socket)//step 4{ var connection new Connection(this, socket);connection.Start();
}private FuncConnectionContext, Frame FrameFactory ListenerContext.ServiceContext.FrameFactory;public Connection(ListenerContext context, UvStreamHandle socket) : base(context)//step 5{SocketInput new SocketInput(Thread.Memory, ThreadPool, _bufferSizeControl);SocketOutput new SocketOutput(Thread, _socket, this, ConnectionId, Log, ThreadPool); //重点代码在这里FrameFactory是一个委托是KestrelServer.Start中注册的action_frame FrameFactory(this);
} public void Start()//step 6{Log.ConnectionStart(ConnectionId); // Start socket prior to applying the ConnectionFilter_socket.ReadStart(_allocCallback, _readCallback, this);_frame.Start();
}/// summary/// Called once by Connection class to begin the RequestProcessingAsync loop./// /summarypublic void Start()//step 7{Reset();_requestProcessingTask Task.Factory.StartNew((o) ((Frame)o).RequestProcessingAsync(), this, default(CancellationToken),TaskCreationOptions.DenyChildAttach,TaskScheduler.Default).Unwrap();
}/// summary/// 主循环消耗套接字输入将其解析为协议帧并调用应用程序委托只要套接字打算保持打开。/// 从此循环得到的任务将保留在服务器需要时使用的字段中以排除和关闭所有当前活动的连接。/// /summarypublic override async Task RequestProcessingAsync(){ while (!_requestProcessingStopping){InitializeHeaders(); var context _application.CreateContext(this); await application.ProcessRequestAsync(context).ConfigureAwait(false);}
} 相关文章: .net core 源码解析-web app是如何启动并接收处理请求 原文地址http://www.cnblogs.com/calvinK/p/6126020.html .NET社区新闻深度好文微信中搜索dotNET跨平台或扫描二维码关注
