using System;

using System.Collections.Generic;

using System.Threading;

using System.Threading.Tasks;

namespace uhttpsharp

{

public class AsyncBlockingQueue<T> : IAsyncBlockingQueue<T>

{

private readonly object _syncRoot = new object();

private readonly Queue<T> _queue;

private readonly SemaphoreSlim _releaseDequeueEvent;

private readonly SemaphoreSlim _releaseEnqueueEvent;

public AsyncBlockingQueue(int capacity)

{

_queue = new Queue<T>(capacity);

_releaseDequeueEvent = new SemaphoreSlim(0, capacity);

_releaseEnqueueEvent = new SemaphoreSlim(capacity, capacity);

}

public async Task<T> Dequeue()

{

T item;

await _releaseDequeueEvent.WaitAsync();

lock (_syncRoot)

{

item = _queue.Dequeue();

}

_releaseEnqueueEvent.Release();

return item;

}

public async Task Enqueue(T item)

{

await _releaseEnqueueEvent.WaitAsync();

lock (_syncRoot)

{

_queue.Enqueue(item);

}

_releaseDequeueEvent.Release();

}

public void Dispose()

{

_releaseEnqueueEvent.Dispose();

_releaseDequeueEvent.Dispose();

}

}

}