我有单线程进程,执行了很长时间.我需要几个用户才能访问执行此过程,我选择http协议来管理调用.
当然,当一个过程正在运行时,其他人应该等到它完成.如果进程可用,则执行.如果没有,则发送BUSY应答.
这是实施：
using System;
using System.Net;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Threading;
using System.Threading.Tasks;
namespace simplehttp
{
class Program
{
private static System.AsyncCallback task;
private static System.Threading.ManualResetEvent mre = new System.Threading.ManualResetEvent(false);// Notifies one or more waiting threads that an event has occurred.
private static HttpListenerContext workingContext = null;
public static bool isBackgroundWorking()
{
return mre.WaitOne(0);
}
static void Main(string[] args)
{
new Thread(() =>
{
Thread.CurrentThread.IsBackground = true;
while (true)
{
Console.WriteLine(" waitOne " + isBackgroundWorking());
mre.WaitOne(); // Blocks the current thread until the current WaitHandle receives a signal.
Console.WriteLine(" do job" + " [" + Thread.CurrentThread.Name + ":" + Thread.CurrentThread.ManagedThreadId + " ]\n");
HttpListenerRequest request = workingContext.Request;
HttpListenerResponse response = workingContext.Response;
string responseString = "WORK " + DateTime.Now ;
byte[] buffer = System.Text.Encoding.UTF8.GetBytes(responseString);
response.ContentLength64 = buffer.Length;
System.IO.Stream output = response.OutputStream;
Thread.Sleep(10000);
output.Write(buffer,buffer.Length);
output.Close();
Console.WriteLine(" " + responseString + "\t" + DateTime.Now);
workingContext = null;
mre.Reset(); // Sets the state of the event to nonsignaled,causing threads to block.
}
}).Start();
// Create a listener.
HttpListener listener = new HttpListener();
listener.Prefixes.Add("http://localhost:6789/index/");
listener.Start();
Console.WriteLine("Listening..." + " [" + Thread.CurrentThread.Name + ":" + Thread.CurrentThread.ManagedThreadId + " ]\n");
task = new AsyncCallback(ListenerCallback);
IAsyncResult resultM = listener.BeginGetContext(task,listener);
Console.WriteLine("Waiting for request to be processed asyncronously.");
Console.ReadKey();
Console.WriteLine("Request processed asyncronously.");
listener.Close();
}
private static void ListenerCallback(IAsyncResult result)
{
HttpListener listener = (HttpListener) result.AsyncState;
//If not listening return immediately as this method is called one last time after Close()
if (!listener.IsListening)
return;
HttpListenerContext context = listener.EndGetContext(result);
listener.BeginGetContext(task,listener);
if (workingContext == null && !isBackgroundWorking())
{
// Background work
workingContext = context;
mre.Set(); //Sets the state of the event to signaled,allowing one or more waiting threads to proceed.
}
else
{
HttpListenerRequest request = context.Request;
HttpListenerResponse response = context.Response;
string responseString = "BUSY "+ DateTime.Now + " [" + Thread.CurrentThread.Name + ":" + Thread.CurrentThread.ManagedThreadId;
byte[] buffer = System.Text.Encoding.UTF8.GetBytes(responseString);
response.ContentLength64 = buffer.Length;
System.IO.Stream output = response.OutputStream;
output.Write(buffer,buffer.Length);
output.Close();
Console.WriteLine(responseString + "\t" + DateTime.Now);
}
}
}
}
为了测试我做2个http调用.我希望有2个不同的答案WORK和BUSY.
但是我看到第二个请求先等待完成然后执行.
waitOne False
Listening... [:10 ]
Waiting for request to be processed asyncronously.
do job [:11 ]
WORK 1/24/2016 10:34:01 AM 1/24/2016 10:34:11 AM
waitOne False
do job [:11 ]
WORK 1/24/2016 10:34:11 AM 1/24/2016 10:34:21 AM
waitOne False
我理解它应该如何运作有什么问题？
更新(太多评论没有被SO鼓励)：
我的代码看起来很尴尬,因为它是真实进程的复制.在“我的”应用程序中,工作过程是主要过程,在某些特定时刻运行嵌入式C#代码具有“礼貌”.因此,我无法运行新任务来处理请求,并且它必须是异步的,因为工作流程完成自己的工作,并且只调用从属代码片段以在数据可用时通知客户端.它是异步的,因为代码被调用并且应该尽快完成,否则它将阻止主应用程序.
我将尝试添加其他线程与同步调用,并看到它影响情况.
此示例中未使用调试器来干扰打印到控制台的实时进程和时间戳.调试很棒且必要但在这种情况下我尝试用输出替换以避免同步/等待场景中的额外actor.
应用程序本身并不是繁重的对话. 1-3个客户很少向主要申请人询问答案. http协议用于方便而不是繁重或经常对话.看起来像IE这样的浏览器工作正常(Windows到Windows会话？),有些像Chrome(更多系统不可知)复制我的应用程序行为.看看时间戳,Chrome,IE,Chrome和最后一个Chrome仍然进入了WORK流程.顺便说一句,每个会话建议更改代码,现在在检索前一个请求后立即发出新请求.
HttpListenerContext context = listener.EndGetContext(result);
listener.BeginGetContext(task,listener);
另外,根据建议,我改变了对syncroniuos的异步调用,结果仍然相同
private static void ListenerCallback(IAsyncResult result)
{
HttpListener listener = (HttpListener) result.AsyncState;
//If not listening return immediately as this method is called one last time after Close()
if (!listener.IsListening)
return;
HttpListenerContext context = listener.EndGetContext(result);
while (true)
{
if (workingContext == null && !isBackgroundWorking())
{
// Background work
workingContext = context;
mre.Set(); //Sets the state of the event to signaled,allowing one or more waiting threads to proceed.
}
else
{
HttpListenerRequest request = context.Request;
HttpListenerResponse response = context.Response;
string responseString = "BUSY " + DateTime.Now + " [" + Thread.CurrentThread.Name + ":" +
Thread.CurrentThread.ManagedThreadId;
byte[] buffer = System.Text.Encoding.UTF8.GetBytes(responseString);
response.ContentLength64 = buffer.Length;
System.IO.Stream output = response.OutputStream;
output.Write(buffer,buffer.Length);
output.Close();
Console.WriteLine(responseString + "\t" + DateTime.Now);
}
context=listener.GetContext();
}
}
