python framework threads_Threads 线程

最新推荐文章于 2022-09-20 11:48:27 发布

原创最新推荐文章于 2022-09-20 11:48:27 发布 · 124 阅读

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#python framework threads

本文详细讲解了多线程的概念及其特点，包括线程同步与异步、线程池的使用、Task与并行计算。通过示例代码展示了如何在C#中实现线程等待、回调、线程安全以及线程取消等操作，深入探讨了异步编程的原理和应用场景。

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usingSystem;usingSystem.Collections.Generic;usingSystem.ComponentModel;usingSystem.Data;usingSystem.Diagnostics;usingSystem.Drawing;usingSystem.Linq;usingSystem.Text;usingSystem.Threading;usingSystem.Threading.Tasks;usingSystem.Windows.Forms;namespaceMyThreads

{///

///1 作业讲解，事件回顾///2 进程-线程-多线程，同步和异步///3 异步使用和回调///4 异步参数///5 异步等待///6 异步返回值///

///1 多线程的特点：不卡主线程、速度快、无序性///2 thread：线程等待，回调，前台线程/后台线程，///3 threadpool：线程池使用，设置线程池，ManualResetEvent///4 Task初步接触///

///1 task：waitall waitany continueWhenAny continueWhenAll///2 并行运算Parallel///3 异常处理、线程取消、多线程的临时变量和lock///4 Await/Async///5 作业///

public partial classForm1 : Form

{publicForm1()

{

Console.WriteLine("今天多线程课程================================================");

InitializeComponent();

}#region btnSync_Click

///

///同步方法///

///

private void btnSync_Click(objectsender, EventArgs e)

{

Stopwatch watch= newStopwatch();

watch.Start();

Console.WriteLine();

Console.WriteLine("**********************btnSync_Click Start 主线程id {0}****************************************", Thread.CurrentThread.ManagedThreadId);for (int i = 0; i < 5; i++)

{string name = string.Format("btnSync_Click_{0}", i);

TestThread(name);

}

watch.Stop();

Console.WriteLine("**********************btnSync_Click End 主线程id {0} {1}*******************************", Thread.CurrentThread.ManagedThreadId, watch.ElapsedMilliseconds);

Console.WriteLine();

}#endregion

#region btnAsync_Click

///

///委托的异步调用///异步多线程的三大特点：///1 同步方法卡界面，原因是主线程被占用；异步方法不卡界面，原因是计算交给了别的线程，主线程空闲///2 同步方法慢，原因是只有一个线程计算；异步方法快，原因是多个线程同时计算，但是更消耗资源，不宜太多///3 异步多线程是无序的，启动顺序不确定、执行时间不确定、结束时间不确定///

///

private void btnAsync_Click(objectsender, EventArgs e)

{

Stopwatch watch= newStopwatch();

watch.Start();

Console.WriteLine();

Console.WriteLine("***********************btnAsync_Click Start 主线程id {0}**********************************", Thread.CurrentThread.ManagedThreadId);for (int i = 0; i < 5; i++)

{string name = string.Format("btnAsync_Click_{0}", i);

Action act= () => this.TestThread(name);//AsyncCallback actCallback = t => Console.WriteLine("123");//act.BeginInvoke(actCallback, null);

act.BeginInvoke(null, null);//ThreadStart method = () => this.TestThread(name);//Action callback = () => Console.WriteLine("123");//this.ThreadCallback(method, callback);

}

watch.Stop();

Console.WriteLine("**********************btnAsync_Click End 主线程id {0} {1}************************************", Thread.CurrentThread.ManagedThreadId, watch.ElapsedMilliseconds);

Console.WriteLine();

}#endregion

#region btnThread_Click

///

///Threads///

///

private void btnThread_Click(objectsender, EventArgs e)

{

Stopwatch watch= newStopwatch();

watch.Start();

Console.WriteLine();

Console.WriteLine("***********************btnThread_Click Start 主线程id {0}**********************************", Thread.CurrentThread.ManagedThreadId);

List threadList = new List();for (int i = 0; i < 5; i++)

{string name = string.Format("btnThread_Click_{0}", i);

ThreadStart method= () => this.TestThread(name);

Thread thread= new Thread(method);//1 默认前台线程：程序退出后，计算任务会继续

thread.IsBackground = true;//2 后台线程：程序退出，计算立即结束

thread.Start();

threadList.Add(thread);//ParameterizedThreadStart method = o => this.TestThread(o.ToString());//Thread thread = new Thread(method);//thread.Start(name);

}foreach (Thread thread inthreadList)

{

thread.Join();

}

watch.Stop();

Console.WriteLine("**********************btnThread_Click End 主线程id {0} {1}************************************", Thread.CurrentThread.ManagedThreadId, watch.ElapsedMilliseconds);

Console.WriteLine();

}///

///使用Thread 完成多线程回调///

/// 要多线程执行的任务

/// 回调执行的任务

private voidThreadBeginInvoke(ThreadStart method, Action callback)

{

ThreadStart methodAll= new ThreadStart(() =>{

method.Invoke();

callback.Invoke();

});

Thread thread= newThread(methodAll);

thread.Start();

}#endregion

#region btnThreadPool_Click

///

private void btnThreadPool_Click(objectsender, EventArgs e)

{

Stopwatch watch= newStopwatch();

watch.Start();

Console.WriteLine();

Console.WriteLine("***********************btnThreadPool_Click Start 主线程id {0}**********************************", Thread.CurrentThread.ManagedThreadId);//for (int i = 0; i < 5; i++)//{//string name = string.Format("btnThreadPool_Click_{0}", i);//WaitCallback method = t => this.TestThread(t.ToString());//ThreadPool.QueueUserWorkItem(method, name);//}

ManualResetEvent mre = new ManualResetEvent(false);

WaitCallback method= t =>{this.TestThread(t.ToString());

mre.Set();

};

ThreadPool.QueueUserWorkItem(method,"TestManualResetEvent");

Console.WriteLine("我们来干点别的。。。。");

mre.WaitOne();//ManualResetEvent mre = new ManualResetEvent(false);//new Action(() =>//{//Thread.Sleep(5000);//Console.WriteLine("委托的异步调用");//mre.Set();//打开//}).BeginInvoke(null, null);//mre.WaitOne();//Console.WriteLine("12345");//mre.Reset();//关闭//new Action(() =>//{//Thread.Sleep(5000);//Console.WriteLine("委托的异步调用2");//mre.Set();//打开//}).BeginInvoke(null, null);//mre.WaitOne();//Console.WriteLine("23456");//ThreadPool.SetMaxThreads(8, 8);//最小也是核数//ThreadPool.SetMinThreads(8, 8);//int workerThreads;//int ioThreads;//ThreadPool.GetMaxThreads(out workerThreads, out ioThreads);//Console.WriteLine(String.Format("Max worker threads: {0}; Max I/O threads: {1}", workerThreads, ioThreads));//ThreadPool.GetMinThreads(out workerThreads, out ioThreads);//Console.WriteLine(String.Format("Min worker threads: {0}; Min I/O threads: {1}", workerThreads, ioThreads));//ThreadPool.GetAvailableThreads(out workerThreads, out ioThreads);//Console.WriteLine(String.Format("Available worker threads: {0}; Available I/O threads: {1}", workerThreads, ioThreads));

watch.Stop();

Console.WriteLine("**********************btnThreadPool_Click End 主线程id {0} {1}************************************", Thread.CurrentThread.ManagedThreadId, watch.ElapsedMilliseconds);

Console.WriteLine();

}#endregion

#region btnTask_Click

///

///Task///

///

private void btnTask_Click(objectsender, EventArgs e)

{

Stopwatch watch= newStopwatch();

watch.Start();

Console.WriteLine();

Console.WriteLine("***********************btnTask_Click Start 主线程id {0}**********************************", Thread.CurrentThread.ManagedThreadId);//new Action(() =>//{

TaskFactory taskFactory= newTaskFactory();

List taskList = new List();for (int i = 0; i < 5; i++)

{string name = string.Format("btnAsync_Click_{0}", i);//Action act = () => this.TestThread(name);//Task task = taskFactory.StartNew(act);

Action act = t => this.TestThread(name);

Task task=taskFactory.StartNew(act, name);//task.ContinueWith(t =>//{// //t.AsyncState//Console.WriteLine("这里是ContinueWhenAny {0}", Thread.CurrentThread.ManagedThreadId);//});

taskList.Add(task);//Task task = new Task(act);//task.Start();//Task task = Task.Run(act);

}

Task any= taskFactory.ContinueWhenAny(taskList.ToArray(), t =>{//t.AsyncState

Console.WriteLine("这里是ContinueWhenAny {0}", Thread.CurrentThread.ManagedThreadId);

});

Task all= taskFactory.ContinueWhenAll(taskList.ToArray(), tList =>{

Console.WriteLine("这里是ContinueWhenAll {0}", Thread.CurrentThread.ManagedThreadId);

});//name="btnAsync_Click_{2}"//Task.WaitAny(task);

Task.WaitAny(taskList.ToArray());//执行的线程等待某一个task的完成

Console.WriteLine("after WaitAny{0}", Thread.CurrentThread.ManagedThreadId);

Task.WaitAll(taskList.ToArray());//执行的线程等待全部的task的完成

Console.WriteLine("after WaitAll{0}", Thread.CurrentThread.ManagedThreadId);//}).BeginInvoke(null, null);//Console.WriteLine("out BeginInvoke");

watch.Stop();

Console.WriteLine("**********************btnTask_Click End 主线程id {0} {1}************************************", Thread.CurrentThread.ManagedThreadId, watch.ElapsedMilliseconds);

Console.WriteLine();

}#endregion

#region btnParallel_Click

///

///并行计算///

///

private void btnParallel_Click(objectsender, EventArgs e)

{

Stopwatch watch= newStopwatch();

watch.Start();

Console.WriteLine();

Console.WriteLine("***********************btnParallel_Click Start 主线程id {0}**********************************", Thread.CurrentThread.ManagedThreadId);//Parallel.Invoke(() => this.TestThread("btnParallel_Click_0")//, () => this.TestThread("btnParallel_Click_1")//, () => this.TestThread("btnParallel_Click_2")//, () => this.TestThread("btnParallel_Click_3")//, () => this.TestThread("btnParallel_Click_4"));//等于使用4个task，然后主线程同步invoke一个委托然后主线程waitall//Parallel.For(6, 10, t =>//{//string name = string.Format("For btnParallel_Click_{0}", t);//this.TestThread(name);//});//Parallel.ForEach(new int[] { 5, 6, 7, 10, 8473847 }, t =>//{//string name = string.Format("ForEach btnParallel_Click_{0}", t);//this.TestThread(name);//});

ParallelOptions parallelOptions= newParallelOptions()

{

MaxDegreeOfParallelism= 5};

Parallel.For(6, 15, parallelOptions, (t, state) =>{string name = string.Format("btnParallel_Click_{0}", t);this.TestThread(name);//state.Break();//退出单次循环//state.Stop();//退出全部的循环//return;

});

watch.Stop();

Console.WriteLine("**********************btnParallel_Click End 主线程id {0} {1}************************************", Thread.CurrentThread.ManagedThreadId, watch.ElapsedMilliseconds);

Console.WriteLine();

}#endregion

#region btnThreadCore_Click

private int TotalCount = 0;private static List IntList = new List();private static object btnThreadCore_Click_Lock = new object();///

///异常处理、线程取消、多线程的临时变量和线程安全lock///

///

private void btnThreadCore_Click(objectsender, EventArgs e)

{

Stopwatch watch= newStopwatch();

watch.Start();

Console.WriteLine();

Console.WriteLine("***********************btnThreadCore_Click Start 主线程id {0}**********************************", Thread.CurrentThread.ManagedThreadId);try{

TaskFactory taskFactory= newTaskFactory();

List taskList = new List();#region 异常处理

//多线程的委托是不允许异常的， try catch包住，写下日志//for (int i = 0; i < 20; i++)//{//string name = string.Format("btnThreadCore_Click{0}", i);//Action act = t =>//{//try//{//Thread.Sleep(2000);//if (t.ToString().Equals("btnThreadCore_Click11"))//{//throw new Exception(string.Format("{0} 执行失败", t));//}//if (t.ToString().Equals("btnThreadCore_Click12"))//{//throw new Exception(string.Format("{0} 执行失败", t));//}//Console.WriteLine("{0} 执行成功", t);//}//catch (Exception ex)//{//Console.WriteLine(ex.Message);//}//};//taskList.Add(taskFactory.StartNew(act, name));//}//Task.WaitAll(taskList.ToArray());

#endregion

#region 线程取消

////Task不能主动取消，只能通过信号量检查的方式

//CancellationTokenSource cts = new CancellationTokenSource();//for (int i = 0; i < 40; i++)//{//string name = string.Format("btnThreadCore_Click{0}", i);//Action act = t =>//{//try//{// //if (cts.IsCancellationRequested)// //{// //Console.WriteLine("{0} 取消一个任务的执行", t);// //}//Thread.Sleep(2000);//if (t.ToString().Equals("btnThreadCore_Click11"))//{//throw new Exception(string.Format("{0} 执行失败", t));//}//if (t.ToString().Equals("btnThreadCore_Click12"))//{//throw new Exception(string.Format("{0} 执行失败", t));//}//if (cts.IsCancellationRequested)//{//Console.WriteLine("{0} 放弃执行", t);//}//else//{//Console.WriteLine("{0} 执行成功", t);//}//}//catch (Exception ex)//{//cts.Cancel();//Console.WriteLine(ex.Message);//}//};//taskList.Add(taskFactory.StartNew(act, name, cts.Token));//没有启动的任务在Cancel后放弃启动//}//Task.WaitAll(taskList.ToArray());

#endregion

#region 多线程临时变量

//for (int i = 0; i < 5; i++)//{// //int k = i;//new Action(() =>//{// //Thread.Sleep(100);//Console.WriteLine(i);// //Console.WriteLine(k);//}).BeginInvoke(null, null);//}//foreach (var item in collection)//{// //做了事件的注册每次用的都是item//}

#endregion

#region 线程安全 lock

for (int i = 0; i < 10000; i++)

{int newI =i;

taskList.Add(taskFactory.StartNew(()=>{int k = 2;int w = 3;int iResult = k +w;lock(btnThreadCore_Click_Lock)

{this.TotalCount += 1;

IntList.Add(newI);

}

}));

}

Task.WaitAll(taskList.ToArray());

Console.WriteLine(this.TotalCount);

Console.WriteLine(IntList.Count());#endregion}catch(AggregateException aex)

{foreach (var item inaex.InnerExceptions)

{

Console.WriteLine(item.Message);

}

}catch(Exception ex)

{

Console.WriteLine(ex.Message);

}

watch.Stop();

Console.WriteLine("**********************btnThreadCore_Click End 主线程id {0} {1}************************************", Thread.CurrentThread.ManagedThreadId, watch.ElapsedMilliseconds);

Console.WriteLine();

}#endregion

#region Private Method

///

///执行动作:耗时而已///

private void TestThread(stringthreadName)

{

Console.WriteLine("TestThread Start Name={2}当前线程的id:{0}，当前时间为{1},", System.Threading.Thread.CurrentThread.ManagedThreadId, DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss:fff"), threadName);long sum = 0;for (int i = 1; i < 999999999; i++)

{

sum+=i;

}//Thread.Sleep(1000);

Console.WriteLine("TestThread End Name={2}当前线程的id:{0}，当前时间为{1},计算结果{3}", System.Threading.Thread.CurrentThread.ManagedThreadId, DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss:fff"), threadName, sum);

}#endregion}

}