我是 CSharp 和线程的新手。

为了熟悉Monitor.Wait、Monitor.lock和Monitor.PulseAll，我构建了一个场景描述如下。

<我> “一个 FootballGround 由不同的球队共享用于练习目的。任何时候只有一个球队可以使用 field 进行练习。一个团队可以使用 field 进行 30 分钟的练习。一旦时间达到 25 分钟，它应该向其他球队发出信号地面将在 5 分钟后释放的线程。本地面潮湿时(枚举有三个值 free、alloted、wet)不允许任何团队锁定地面，所有人都应等待 10 分钟”

老实说，我不知道如何将描述转化为实际编码。根据我的理解，我设计了大纲。

namespace ThreadingSimulation
 {

  // A Random Activity can be picked up from this enum by a team

         public enum RandomGroundStatus
         {
             free,
             allotted,
             Wet          
         }

class FootBallGround
{

    public void Playing(object obj)
    {
      // Here the name of the team which is using the  ground will be printed
      // Once the time is reached to 25 minnutes the active thread acquired
      // the lock will signal  other threads    

    }

   public void GroundCleaningInProgress(object obj)
   {

      // Ground cleaning is in progress all of you
      // wait for 10 minutes

   }

}    




 class Team
   {
     string teamName;  

      static void Main()
      {

        //select random value for GrandStatus from enum

       // if the ground is wet no team is allowed to get the
       // ground for 10 minutes  

        //if the ground is free "Team A" locks the ground

        // otherwise "Team B" locks the ground

      }

   }

}

这里我不知道如何应用锁和信号。请帮助我。

最佳答案

实际上，您的场景并没有很大程度地映射到锁 - 但无论如何我们都会尝试；-p

我稍微调整了设置；相反:

• 一次可以有一个实体
• 当一个团队完成后，他们会告诉他们看到的第一个人(如果有人在等)
• 当清洁工结束时，他们很吵 - 所以每个人都注意到他们离开并试图上场

这是代码；请注意，他们在使用 field 时没有锁，因为那样会阻止其他人加入 Pulse 队列。

实际上，我们可以用 lock 完成所有这些操作(根本不使用 Pulse) ，并且只使用标准的阻塞行为。但此示例显示 Pulse 和 PulseAll 用于在满足条件时重新激活线程。

using System;
using System.Threading;
interface IGroundUser
{
    bool Invoke(); // do your stuff; return true to wake up *everyone*
                   // afterwards, else false
}
class Team : IGroundUser
{
    private readonly string name;
    public Team(string name) { this.name = name; }
    public override string ToString() { return name; }
    public bool Invoke()
    {
        Console.WriteLine(name + ": playing...");
        Thread.Sleep(25 * 250);
        Console.WriteLine(name + ": leaving...");
        return false;
    }
}
class Cleaner : IGroundUser
{
    public override string ToString() {return "cleaner";}
    public bool Invoke()
    {
        Console.WriteLine("cleaning in progress");
        Thread.Sleep(10 * 250);
        Console.WriteLine("cleaning complete");
        return true;
    }
}
class FootBallGround
{
    static void Main()
    {
        var ground = new FootBallGround();
        ThreadPool.QueueUserWorkItem(delegate { ground.UseGrounds(new Team("Team A")); });
        ThreadPool.QueueUserWorkItem(delegate { ground.UseGrounds(new Team("Team B")); });
        ThreadPool.QueueUserWorkItem(delegate { ground.UseGrounds(new Cleaner()); });
        ThreadPool.QueueUserWorkItem(delegate { ground.UseGrounds(new Team("Team C")); });
        ThreadPool.QueueUserWorkItem(delegate { ground.UseGrounds(new Team("Team D")); });
        ThreadPool.QueueUserWorkItem(delegate { ground.UseGrounds(new Team("Team E")); });
        Console.ReadLine();

    }
    bool busy;
    private readonly object syncLock = new object();
    public void UseGrounds(IGroundUser newUser)
    {
        // validate outside of lock
        if (newUser == null) throw new ArgumentNullException("newUser");
        // only need the lock when **changing** state
        lock (syncLock)
        {
            while (busy)
            {
                Console.WriteLine(newUser + ": grounds are busy; waiting...");
                Monitor.Wait(syncLock);
                Console.WriteLine(newUser + ": got nudged");
            }
            busy = true; // we've got it!
        }
        // do this outside the lock, allowing other users to queue
        // waiting for it to be free
        bool wakeAll = newUser.Invoke();

        // exit the game
        lock (syncLock)
        {
            busy = false;
            // wake up somebody (or everyone with PulseAll)
            if (wakeAll) Monitor.PulseAll(syncLock);
            else Monitor.Pulse(syncLock);
        }
    }    
}    

关于C# 线程 : Using Monitor. 等待、锁定和 PulseAll，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/1565240/