如何使用c＃中的队列？ 我想要一个将数据排入队列的线程＆amp;另一个线程将数据从队列中出列。那些线程应该同时运行。
有可能吗？
答案 0 :(得分：8)
如果您需要使用线程安全ConcurrentQueue<T>。
答案 1 :(得分：2)
如果您使用System.Collections.Queue线程安全，则以这种方式保证：
var queue = new Queue();
Queue.Synchronized(queue).Enqueue(new WorkItem());
Queue.Synchronized(queue).Enqueue(new WorkItem());
Queue.Synchronized(queue).Clear();
如果你想使用System.Collections.Generic.Queue<T>，那么创建你自己的包装类。我已经使用System.Collections.Generic.Stack<T>
using System;
using System.Collections.Generic;
[Serializable]
public class SomeStack
{
private readonly object stackLock = new object();
private readonly Stack<WorkItem> stack;
public ContextStack()
{
this.stack = new Stack<WorkItem>();
}
public IContext Push(WorkItem context)
{
lock (this.stackLock)
{
this.stack.Push(context);
}
return context;
}
public WorkItem Pop()
{
lock (this.stackLock)
{
return this.stack.Pop();
}
}
}
答案 2 :(得分：0)
一种可能的实现是使用具有单独的读和写指针的环形缓冲区。在每次读/写操作时，将相反的指针（必须是线程安全的）复制到本地上下文中，然后执行批量读取或写入。
在每次读取或写入时更新指针并发出事件脉冲。
如果读取或写入线程到达没有其他工作要做的地方，则在重新读取相应的指针之前等待其他线程事件。
答案 3 :(得分：0)
您可以使用原子操作实现线程安全队列。我曾经为多人游戏写过以下课程。它允许多个线程安全地写入队列，并允许一个其他线程安全地从队列中读取：
/// <summary>
/// The WaitFreeQueue class implements the Queue abstract data type through a linked list. The WaitFreeQueue
/// allows thread-safe addition and removal of elements using atomic operations. Multiple threads can add
/// elements simultaneously, and another thread can remove elements from the queue at the same time. Only one
/// thread can remove elements from the queue at any given time.
/// </summary>
/// <typeparam name="T">The type parameter</typeparam>
public class WaitFreeQueue<T>
{
// Private fields
// ==============
#region Private fields
private Node<T> _tail; // The tail of the queue.
private Node<T> _head; // The head of the queue.
#endregion
// Public methods
// ==============
#region Public methods
/// <summary>
/// Removes the first item from the queue. This method returns a value to indicate if an item was
/// available, and passes the item back through an argument.
/// This method is not thread-safe in itself (only one thread can safely access this method at any
/// given time) but it is safe to call this method while other threads are enqueueing items.
///
/// If no item was available at the time of calling this method, the returned value is initialised
/// to the default value that matches this instance's type parameter. For reference types, this is
/// a Null reference.
/// </summary>
/// <param name="value">The value.</param>
/// <returns>A boolean value indicating if an element was available (true) or not.</returns>
public bool Dequeue(ref T value)
{
bool succeeded = false;
value = default(T);
// If there is an element on the queue then we get it.
if (null != _head)
{
// Set the head to the next element in the list, and retrieve the old head.
Node<T> head = System.Threading.Interlocked.Exchange<Node<T>>(ref _head, _head.Next);
// Sever the element we just pulled off the queue.
head.Next = null;
// We have succeeded.
value = head.Value;
succeeded = true;
}
return succeeded;
}
/// <summary>
/// Adds another item to the end of the queue. This operation is thread-safe, and multiple threads
/// can enqueue items while a single other thread dequeues items.
/// </summary>
/// <param name="value">The value to add.</param>
public void Enqueue(T value)
{
// We create a new node for the specified value, and point it to itself.
Node<T> newNode = new Node<T>(value);
// In one atomic operation, set the tail of the list to the new node, and remember the old tail.
Node<T> previousTail = System.Threading.Interlocked.Exchange<Node<T>>(ref _tail, newNode);
// Link the previous tail to the new tail.
if (null != previousTail)
previousTail.Next = newNode;
// If this is the first node in the list, we save it as the head of the queue.
System.Threading.Interlocked.CompareExchange<Node<T>>(ref _head, newNode, null);
} // Enqueue()
#endregion
// Public constructor
// ==================
#region Public constructor
/// <summary>
/// Constructs a new WaitFreeQueue instance.
/// </summary>
public WaitFreeQueue() { }
/// <summary>
/// Constructs a new WaitFreeQueue instance based on the specified list of items.
/// The items will be enqueued. The list can be a Null reference.
/// </summary>
/// <param name="items">The items</param>
public WaitFreeQueue(IEnumerable<T> items)
{
if(null!=items)
foreach(T item in items)
this.Enqueue(item);
}
#endregion
// Private types
// =============
#region Private types
/// <summary>
/// The Node class represents a single node in the linked list of a WaitFreeQueue.
/// It contains the queued-up value and a reference to the next node in the list.
/// </summary>
/// <typeparam name="U">The type parameter.</typeparam>
private class Node<U>
{
// Public fields
// =============
#region Public fields
public Node<U> Next;
public U Value;
#endregion
// Public constructors
// ===================
#region Public constructors
/// <summary>
/// Constructs a new node with the specified value.
/// </summary>
/// <param name="value">The value</param>
public Node(U value)
{
this.Value = value;
}
#endregion
} // Node generic class
#endregion
} // WaitFreeQueue class
如果在多个线程可以入队时只有一个线程出队的限制是可以的，那么你可以使用它。这对游戏来说很棒，因为它意味着不需要线程同步。
答案 4 :(得分：0)
示例简单用法是
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
ExampleQueue eq = new ExampleQueue();
eq.Run();
// Wait...
System.Threading.Thread.Sleep(100000);
}
}
class ExampleQueue
{
private Queue<int> _myQueue = new Queue<int>();
public void Run()
{
ThreadPool.QueueUserWorkItem(new WaitCallback(PushToQueue), null);
ThreadPool.QueueUserWorkItem(new WaitCallback(PopFromQueue), null);
}
private void PushToQueue(object Dummy)
{
for (int i = 0; i <= 1000; i++)
{
lock (_myQueue)
{
_myQueue.Enqueue(i);
}
}
System.Console.WriteLine("END PushToQueue");
}
private void PopFromQueue(object Dummy)
{
int dataElementFromQueue = -1;
while (dataElementFromQueue < 1000)
{
lock (_myQueue)
{
if (_myQueue.Count > 0)
{
dataElementFromQueue = _myQueue.Dequeue();
// Do something with dataElementFromQueue...
System.Console.WriteLine("Dequeued " + dataElementFromQueue);
}
}
}
System.Console.WriteLine("END PopFromQueue");
}
}
}
答案 5 :(得分：0)
您可能希望使用阻塞队列，其中从队列弹出的线程将等到某些数据可用。