我是线程技术的新手，我正在尝试学习不同的概念。
现在，我正在使用计时器线程进行生产者/消费者模式。问题是我不知道如何在让Timer线程滴答特定时间之前检查所有生产者线程和使用者线程是否都已完成其进程，并为下一个滴答处理所有创建的生产者线程和使用者线程。
想请教您有关如何为该方法创建变通方法的帮助和指导。
这是我的示例代码：
public class WorkerThread
{
public BlockingQueue<Item> collection = new BlockingQueue<Item>(100);
private Timer TimerThread { get; set; }
public void ThreadTimer()
{
this.TimerThread = new Timer(new TimerCallback(StartMonitor), null, 500, Timeout.Infinite);
}
public void StartMonitor(object state)
{
List<Thread> producers = new List<Thread>();
List<Thread> consumers = new List<Thread>();
for (int i = 0; i < 1; i++)
{
producers.Add(new Thread(() => RunProducers(this.collection)));
}
//TODO: Start all producer threads...
for (int i = 0; i < 2; i++)
{
consumers.Add(new Thread(() => RunConsumers(this.collection)));
}
//TODO: Start all consumer threads...
//TODO: Let Thread wait until all worker threads are done
//TODO: Dispose Threads
TimerThread.Change(5000, Timeout.Infinite);
}
public void RunProducers(BlockingQueue<Item> collection)
{
List<Item> lsItems = CreateListOfItems();
foreach(var item in lsItems)
{
collection.Add(item);
}
}
public void RunConsumers(BlockingQueue<Item> collection)
{
while(true)
{
Item item = collection.Take();
Console.WriteLine("Processed[{0}] : {1}", item.ID, item.Name);
//Thread.Sleep(100);
}
}
public List<Item> CreateListOfItems()
{
List<Item> lsItems = new List<Item>();
for (int i = 0; i <= 9999; i++)
{
lsItems.Add(new Item() { ID = i, Name = "Item[" + i + "]" });
}
return lsItems;
}
}
BlockCollection实现（由于我们的环境在.Net 3.5中，因此我们无法在更高版本上使用库。
public class BlockingQueue<T>
{
private readonly Queue<T> queue = new Queue<T>();
private readonly int MaxSize;
public bool closing;
public BlockingQueue(int maxSize) {
this.MaxSize = maxSize;
}
public void Add(T item)
{
lock(queue)
{
while(queue.Count >= this.MaxSize)
{
Monitor.Wait(queue);
}
queue.Enqueue(item);
if(queue.Count == 1)
{
Monitor.PulseAll(queue);
}
}
}
public T Take()
{
lock(queue)
{
while(queue.Count == 0)
{
Monitor.Wait(queue);
}
T item = queue.Dequeue();
if(queue.Count == MaxSize - 1)
{
Monitor.PulseAll(queue);
}
return item;
}
}
public void Close()
{
lock (queue)
{
closing = true;
Monitor.PulseAll(queue);
}
}
public bool TryDequeue(out T value)
{
lock (queue)
{
while (queue.Count == 0)
{
if (closing)
{
value = default(T);
return false;
}
Monitor.Wait(queue);
}
value = queue.Dequeue();
if (queue.Count == MaxSize - 1)
{
Monitor.PulseAll(queue);
}
return true;
}
}
}
答案 0 :(得分：0)
您可以仅检查所有工作线程的属性IsAlive。看起来不是很清晰的代码，但是可以正常工作：
public void StartMonitor(object state)
{
List<Thread> producers = new List<Thread>();
List<Thread> consumers = new List<Thread>();
for (int i = 0; i < 1; i++)
{
producers.Add(new Thread(() => RunProducers(this.collection)));
}
//TODO: Start all producer threads...
for (int i = 0; i < 2; i++)
{
consumers.Add(new Thread(() => RunConsumers(this.collection)));
}
//TODO: Let Thread wait until all worker threads are done
List<Thread> to_check = new List<Thread>(producers);
to_check.AddRange(consumers);
while(true)
{
Thread.Sleep(50);
List<Thread> is_alive = new List<Thread>();
foreach(Thread t in to_check)
if(t.IsAlive)
is_alive.Add(t);
if(is_alive.Count == 0)
break;
to_check = is_alive;
}
//TODO: Dispose Threads
TimerThread.Change(5000, Timeout.Infinite);
}
或者，也许是更好的方法：
private int[] _counter = new int[1];
private int Counter
{
get
{
lock (_counter) { return _counter[0]; }
}
set
{
lock (_counter) { _counter[0] = value; }
}
}
public void StartMonitor(object state)
{
List<Thread> producers = new List<Thread>();
List<Thread> consumers = new List<Thread>();
Counter = 0;
for (int i = 0; i < 1; i++)
{
producers.Add(new Thread(() => { Counter++; RunProducers(this.collection); Counter--; }));
}
//TODO: Start all producer threads...
for (int i = 0; i < 2; i++)
{
consumers.Add(new Thread(() => { Counter++; RunConsumers(this.collection); Counter--; }));
}
//TODO: Let Thread wait until all worker threads are done
List<Thread> to_check = new List<Thread>(producers);
to_check.AddRange(consumers);
while (Counter > 0)
Thread.Sleep(50);
//TODO: Dispose Threads
TimerThread.Change(5000, Timeout.Infinite);
}
要避免使用Sleep（），可以使用Barrier类：
public void StartMonitor(object state)
{
List<Thread> producers = new List<Thread>();
List<Thread> consumers = new List<Thread>();
int producer_cnt = 1,
consumer_cnt = 2;
Barrier b = new Barrier(producer_cnt + consumer_cnt + 1);
try
{
for (int i = 0; i < 1; i++)
{
producers.Add(new Thread(() => { try { RunProducers(this.collection); } finally { b.SignalAndWait(); } }));
}
//TODO: Start all producer threads...
for (int i = 0; i < 2; i++)
{
consumers.Add(new Thread(() => { try { RunConsumers(this.collection); } finally { b.SignalAndWait(); } }));
}
//TODO: Let Thread wait until all worker threads are done
List<Thread> to_check = new List<Thread>(producers);
to_check.AddRange(consumers);
}
finally
{
b.SignalAndWait();
}
//TODO: Dispose Threads
TimerThread.Change(5000, Timeout.Infinite);
}