參數 運行 線程池 lte rtt nts monitor 事情 img

當我們在使用線程中，你會發現主線結束後子線程的結果才顯示出來。現在我要等待所以子線程結束，然後在顯示結果，怎麽做呢？

方法如下：

1、使用 ManualResetEvent，代碼如下：

using System.Threading;

namespace ThreadStudy
{
/// <summary>
/// 等待所有子線程結束
/// </summary>
class StopAllWaitBySubThread
{
List<ManualResetEvent> manualEvents = new List<ManualResetEvent>();
public void Main()
{
for (int i = 0; i < 5; i++)
{
ManualResetEvent mre = new ManualResetEvent(false);
manualEvents.Add(mre);
ThreadPool.QueueUserWorkItem(ThreadMethod, mre);
}
WaitHandle.WaitAll(manualEvents.ToArray());
Console.WriteLine("Thread Finished!");
}

private void ThreadMethod(object obj)
{
//等待2秒，用於模擬系統在處理事情
Thread.Sleep(2000);

ManualResetEvent mre = (ManualResetEvent)obj;
mre.Set();
Console.WriteLine("Thread execute");
}
}
}

此種方法線程中只傳遞了信號，那要傳遞參數怎麽辦？可以采用類，將信號放在類中來解決，代碼如下。

using System.Threading;

namespace ThreadStudy
{
/// <summary>
/// 等待所有子線程結束
/// </summary>
class StopAllWaitBySubThread
{
List<ManualResetEvent> manualEvents = new List<ManualResetEvent>();
public void Main()
{
for (int i = 0; i < 5; i++)
{
ManualResetEvent mre = new ManualResetEvent(false);
manualEvents.Add(mre);
Param pra = new Param();
pra.mrEvent = mre;
pra.praData = i;
ThreadPool.QueueUserWorkItem(ThreadMethod, pra);
}
WaitHandle.WaitAll(manualEvents.ToArray());
Console.WriteLine("Thread Finished!");
}

private void ThreadMethod(object obj)
{
Thread.Sleep(2000);
Param pra = (Param)obj;
pra.mrEvent.Set();
Console.WriteLine("Thread execute at {0}", pra.praData);
}
}

public class Param
{
public ManualResetEvent mrEvent;
public int praData;
}
}

2、判斷線程數

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.Threading;

namespace ThreadStudy
{
/// <summary>
/// 判斷當所有子線程執行完畢
/// </summary>
class ThreadPoolStop
{
public void Main()
{
for (int i = 0; i < 5; i++)
{
ThreadPool.QueueUserWorkItem(new WaitCallback(ThreadMethod), i);
}
int maxWorkerThreads, workerThreads;
int portThreads;
while (true)
{
/*
GetAvailableThreads()：檢索由 GetMaxThreads 返回的線程池線程的最大數目和當前活動數目之間的差值。
而GetMaxThreads 檢索可以同時處於活動狀態的線程池請求的數目。
通過最大數目減可用數目就可以得到當前活動線程的數目，如果為零，那就說明沒有活動線程，說明所有線程運行完畢。
*/
ThreadPool.GetMaxThreads(out maxWorkerThreads, out portThreads);
ThreadPool.GetAvailableThreads(out workerThreads, out portThreads);
if (maxWorkerThreads - workerThreads == 0)
{
Console.WriteLine("Thread Finished!");
break;
}
}
}

private void ThreadMethod(object i)
{
//模擬程序運行 Thread.Sleep((new Random().Next(1, 4)) * 1000);
Console.WriteLine("Thread execute at {0}", i.ToString());
}
}
}

3、使用Monitor

using System.Threading;

namespace ThreadStudy
{
class StopAllSubThread
{
int _ThreadCount = 5;
int finishcount = 0;
object locker = new object();
public void Main()
{
for (int i = 0; i < _ThreadCount; i++)
{
Thread trd = new Thread(new ParameterizedThreadStart(ThreadMethod));
trd.Start(i);
}
lock (locker)
{
while (finishcount != _ThreadCount)
{
Monitor.Wait(locker);//等待
}
}
Console.WriteLine("Thread Finished!");
}

private void ThreadMethod(object obj)
{
//模擬執行程序
Thread.Sleep(3000);
Console.WriteLine("Thread execute at {0}", obj.ToString());
lock (locker)
{
finishcount++;
Monitor.Pulse(locker); //完成，通知等待隊列,告知已完，執行下一個。
}
}
}
}

c#等待所有子線程執行完畢方法