多线程4层混合生产者消费者模式 - 线程没有正确交替

Question

这是我试图建模的问题：我有一个来电呼叫中心（没有外拨电话）。有3个员工级别 - 新生，技术主管，项目经理。在我们的呼叫中心，只有一个TL，一个PM和多个Freshers。新手无法处理的呼叫会升级到TL，并且TL无法处理的呼叫会升级到PM。

我需要采用OO C＃方法。

这是我目前的尝试：我使用C＃ConcurrentQueue，因为我认为它会处理'锁'。我想要呼叫中心的FIFO。我为每个级别排队。

我有一个生产者（调用者）添加对第一个队列的调用。混合产品/消费者新手检查呼叫（接受或升级到下一个队列）。混合产品/消费者tl，然后是纯粹的消费者项目经理。

输出不是我所期望的。只有第一个新鲜运行并且项目经理根本不运行。随着呼叫被添加到队列中，我期待更多的轮换。

我的代码如下。有没有人有更好的方法解决这个问题，或者我的代码有问题吗？

CallCenter类是大多数操作发生的地方。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Collections.Concurrent;
namespace CallCenterThreaded
{
/// <summary>
/// 
/// MIXED CONSUMER/PRODUCER TYPE
/// </summary>
class Fresher
{
    // add a class variable for the number of Employee objects instantiated
    private static int fresherNum = 0;
    private int fresherId;
    private ConcurrentQueue<Call> incommingCalls;
    private ConcurrentQueue<Call> outgoingCalls;

    public Fresher(ConcurrentQueue<Call> calls, ConcurrentQueue<Call> outcalls)
    {
        fresherId = ++fresherNum;
        incommingCalls = calls;
        outgoingCalls = outcalls;
        //start the producer thread
        Thread thread = new Thread(new ThreadStart(HandleCalls));
        thread.Start();
    }

    public int ID
    {
        get { return fresherId; }
    }

    /// <summary>
    /// 
    /// </summary>
    public void HandleCalls() 
    {

        while (incommingCalls.Count > 0)
        {

            Call call;
            incommingCalls.TryDequeue(out call);

            if (call != null)
            {
                if (call.EscalationLevel == 0)
                {
                    TakeCalls(call);
                }
                else 
                {
                    TransferCalls(call);
                }
            }

        }

    }

    /// <summary>
    /// Transfer to the TL
    /// </summary>
    public void TransferCalls(Call call)
    {
        outgoingCalls.Enqueue(call);
        Console.WriteLine(".......Fresher {0} escalated call {1}", ID, call.CallID);
    }

    /// <summary>
    /// Consume the calls
    /// </summary>
    public void TakeCalls(Call call)
    {
        Console.WriteLine("Fresher {0} handled call {1}", ID, call.CallID);
    }



}
}
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading;
    using System.Collections.Concurrent;
   namespace CallCenterThreaded
    {
    /// <summary>
    /// MIXED CONSUMER/PRODUCER TYPE
    /// </summary>
    class TechnicalLead
    {

    // add a class variable for the number of Employee objects instantiated
    private static int tlNum = 0;
    private int tlId;

    private ConcurrentQueue<Call> incommingCalls;
    private ConcurrentQueue<Call> outgoingCalls;

    public TechnicalLead(ConcurrentQueue<Call> calls, ConcurrentQueue<Call> outcalls)
    {
        tlId = ++tlNum;
        incommingCalls = calls;
        outgoingCalls = outcalls;
        //start the producer thread
        Thread thread = new Thread(new ThreadStart(HandleCalls));
        thread.Start();
    }

    public int ID
    {
        get { return tlId; }
    }

    /// <summary>
    /// 
    /// </summary>
    public void HandleCalls() 
    {

        while (incommingCalls.Count > 0)
        {

            Call call;
            incommingCalls.TryDequeue(out call);

            if (call != null)
            {
                if (call.EscalationLevel == 1)
                {
                    TakeCalls(call);
                }
                else 
                {
                    TransferCalls(call);
                }
            }

        }

    }
    /// <summary>
    /// Transfer to the PM
    /// </summary>
    public void TransferCalls(Call call)
    {
        //Console.WriteLine(".......Technical Lead {0} escalated call {1}", ID, call.CallID);
        outgoingCalls.Enqueue(call);           
    }

    /// <summary>
    /// Consume the calls
    /// </summary>
    public void TakeCalls(Call call)
    {
        Console.WriteLine("Technical Lead {0} handled call {1}", ID, call.CallID);
    }
}
}
    using System;
   using System.Collections.Generic;
 using System.Linq;
 using System.Text;
   namespace CallCenterThreaded
   {
class Call
{
    private static int numberCalls = 0;
    private int callno;

    private int esclataion;


    public Call() 
    {
        callno = ++numberCalls;
        esclataion = 0;
        if(callno % 3 == 0)
        {
            esclataion = 1;
        }
        if(callno % 5 == 0)
        {
            esclataion = 2;
        }

    }

    public int CallID { get { return callno; } }
    public int EscalationLevel { get { return esclataion; } }
}
}
 using System;
 using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Collections.Concurrent;
namespace CallCenterThreaded
{
/// <summary>
/// 
/// </summary>
class CallCenter
{

    private ConcurrentQueue<Call> fresherCalls;
    private ConcurrentQueue<Call> tlCalls;
    private ConcurrentQueue<Call> pmCalls;

    private List<Caller> myCallers;
    private List<Fresher> myFreshers;

    private TechnicalLead tl;
    private ProjectManager pm;

    public CallCenter() 
    {
        //initial incomming calls to the fresher queue
        fresherCalls = new ConcurrentQueue<Call>();
        tlCalls = new ConcurrentQueue<Call>();
        pmCalls = new ConcurrentQueue<Call>();

        myFreshers = new List<Fresher>();
        myCallers = new List<Caller>();

        generate_callers();
        generate_freshers();

        tl = new TechnicalLead(tlCalls, pmCalls);
        pm = new ProjectManager(pmCalls);
    }

    /// <summary>
    /// 
    /// </summary>
    private void generate_freshers() 
    {
        for (int i = 0; i < 5; i++ )
        {
            myFreshers.Add(new Fresher(fresherCalls, tlCalls));
        }
    }

    /// <summary>
    /// 
    /// </summary>
    private void generate_callers() 
    {
        for (int i = 0; i < 5; i++ )
        {
            myCallers.Add(new Caller(fresherCalls));
        }
    }

   }
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Collections.Concurrent;
namespace CallCenterThreaded
{
/// <summary>
/// PURE CONSUMER
/// </summary>
class ProjectManager
{

     // add a class variable for the number of Employee objects instantiated
    private static int pmNum = 0;
    private int pmId;

    private ConcurrentQueue<Call> incommingCalls;

    public ProjectManager(ConcurrentQueue<Call> calls)
    {
        pmId = ++pmNum;
        incommingCalls = calls;

        //start the producer thread
        Thread thread = new Thread(new ThreadStart(HandleCalls));
        thread.Start();
    }

    public int ID
    {
        get { return pmId; }
    }

    /// <summary>
    /// 
    /// </summary>
    public void HandleCalls() 
    {

        while (incommingCalls.Count > 0)
        {

            Call call;
            incommingCalls.TryDequeue(out call);

            if (call != null && call.EscalationLevel == 2)
            {
                TakeCalls(call); 
            }

        }

    }
    /// <summary>
    /// Consume the calls
    /// </summary>
    public void TakeCalls(Call call)
    {
        Console.WriteLine("Project Manager {0} handled call {1}", ID, call.CallID);
    }
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Collections.Concurrent;
namespace CallCenterThreaded
{
class MainClass
{
    static void Main(string[] args)
    {

        CallCenter myCenter = new CallCenter();

        Console.ReadLine();
    }
}
}
    using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections.Concurrent;
using System.Threading;
namespace CallCenterThreaded
{
/// <summary>
/// This is a producer. It produces calls and adds them to the queue.
/// PURE PRODUCER TYPE
/// </summary>
class Caller
{

    private ConcurrentQueue<Call> incommingCalls;

    public Caller(ConcurrentQueue<Call> calls)
    {
        incommingCalls = calls;
        //start the producer thread
        Thread thread = new Thread(new ThreadStart(placeCalls));
        thread.Start();
    }

    public void placeCalls()
    {

        //place 10 calls
        for (int callno = 0; callno < 4; callno++)
        {
            //Console.WriteLine("Call {0} was added to the queue", callno);
            incommingCalls.Enqueue(new Call());
        }

    }

}
}

Answer 1

问题在于HandleCalls()方法：

public void HandleCalls() 
{
    while (incommingCalls.Count > 0)
    {
        …
    }
}

这段代码的作用是检查incomingCalls，如果没有，它会立即退出线程。好像工人上班，看着他的电话队列，在那里什么都没找到（因为他和应该重新定向电话的新生同时来上班）所以他就离开了回家。

您需要做的是等待目前没有工作。可能最好的方法是使用BlockingCollection代替ConcurrentQueue。

此外，您的设计似乎并不那么好。例如，有很多重复的代码。