public IAsyncResult BeginDequeue(TimeSpan timeout, AsyncCallback callback, object state)
{
Item <T> item = new Item <T>();
lock (this.ThisLock)
{
if (this.queueState == QueueState <T> .Open)
{
if (!this.itemQueue.HasAvailableItem)
{
AsyncQueueReader <T> reader = new AsyncQueueReader <T>((InputQueue <T>) this, timeout, callback, state);
this.readerQueue.Enqueue(reader);
return(reader);
}
item = this.itemQueue.DequeueAvailableItem();
}
else if (this.queueState == QueueState <T> .Shutdown)
{
if (this.itemQueue.HasAvailableItem)
{
item = this.itemQueue.DequeueAvailableItem();
}
else if (this.itemQueue.HasAnyItem)
{
AsyncQueueReader <T> reader2 = new AsyncQueueReader <T>((InputQueue <T>) this, timeout, callback, state);
this.readerQueue.Enqueue(reader2);
return(reader2);
}
}
}
InputQueue <T> .InvokeDequeuedCallback(item.DequeuedCallback);
return(new CompletedAsyncResult <T>(item.GetValue(), callback, state));
}
static void TimerCallback(object state)
{
AsyncQueueReader thisPtr = (AsyncQueueReader)state;
if (thisPtr.inputQueue.RemoveReader(thisPtr))
{
thisPtr.expired = true;
thisPtr.Complete(false);
}
}
static void CancelCallback(object state)
{
AsyncQueueReader thisPtr = (AsyncQueueReader)state;
thisPtr.cancelRegistration.Dispose();
if (thisPtr.inputQueue.RemoveReader(thisPtr))
{
thisPtr.TrySetCanceled();
}
}
public bool EndDequeue(IAsyncResult result, out T value)
{
if (result is CompletedAsyncResult <T> )
{
value = CompletedAsyncResult <T> .End(result);
return(true);
}
return(AsyncQueueReader <T> .End(result, out value));
}
public static bool End(IAsyncResult result, out T value)
{
AsyncQueueReader readerResult = End <AsyncQueueReader>(result);
if (readerResult.expired)
{
value = default(T);
return(false);
}
value = readerResult.item;
return(true);
}
public bool EndDequeue(IAsyncResult result, out T value)
{
CompletedAsyncResult <T> typedResult = result as CompletedAsyncResult <T>;
if (typedResult != null)
{
value = CompletedAsyncResult <T> .End(result);
return(true);
}
return(AsyncQueueReader.End(result, out value));
}
public IAsyncResult BeginDequeue(TimeSpan timeout, AsyncCallback callback, object state)
{
Item item = default(Item);
lock (ThisLock)
{
if (queueState == QueueState.Open)
{
if (itemQueue.HasAvailableItem)
{
item = itemQueue.DequeueAvailableItem();
}
else
{
AsyncQueueReader reader = new AsyncQueueReader(this, timeout, callback, state);
readerQueue.Enqueue(reader);
return(reader);
}
}
else if (queueState == QueueState.Shutdown)
{
if (itemQueue.HasAvailableItem)
{
item = itemQueue.DequeueAvailableItem();
}
else if (itemQueue.HasAnyItem)
{
AsyncQueueReader reader = new AsyncQueueReader(this, timeout, callback, state);
readerQueue.Enqueue(reader);
return(reader);
}
}
}
InvokeDequeuedCallback(item.DequeuedCallback);
return(new CompletedAsyncResult <T>(item.GetValue(), callback, state));
}
public Task <T> DequeueAsync(CancellationToken cancellationToken, object state)
{
Item item = default(Item);
lock (ThisLock)
{
if (queueState == QueueState.Open)
{
if (itemQueue.HasAvailableItem)
{
item = itemQueue.DequeueAvailableItem();
}
else
{
var reader = new AsyncQueueReader(this, cancellationToken, state);
readerQueue.Enqueue(reader);
return(reader.Task);
}
}
else if (queueState == QueueState.Shutdown)
{
if (itemQueue.HasAvailableItem)
{
item = itemQueue.DequeueAvailableItem();
}
else if (itemQueue.HasAnyItem)
{
AsyncQueueReader reader = new AsyncQueueReader(this, cancellationToken, state);
readerQueue.Enqueue(reader);
return(reader.Task);
}
}
}
InvokeDequeuedCallback(item.DequeuedCallback);
return(Task.FromResult(item.GetValue()));
}
