private async Task <OperationResult <ChannelState> > ReadWithTimeoutAsync(AsynchronousReadingOperation readingOperation, TimeSpan timeout)
{
ThrowIfDisposed();
bool gainedExclusiveAccess = false;
try
{
var status = await AsyncHelper.GetTaskForWaitHandle(_exclusiveAccessSemaphore, timeout);
if (status != OperationStatus.Completed)
{
return(new OperationResult <ChannelState>(status, null));
}
gainedExclusiveAccess = true;
return(await ReadAndSetEventsAsync(readingOperation));
}
finally
{
if (gainedExclusiveAccess)
{
_exclusiveAccessSemaphore.Release();
}
}
}
public async Task <OperationResult <ChannelState> > ReadAsync(AsynchronousReadingOperation readingOperation)
{
var header = Header.Read(_headerView);
if (header.HeadNode < 0)
{
return(new OperationResult <ChannelState>(OperationStatus.QueueIsEmpty, new ChannelState(header)));
}
var offset = header.HeadNode;
var node = Node.Read(_file, header.HeadNode);
var status = await readingOperation.ReadAsync(_file, header.HeadNode + _sizeOfNode, node.Length);
if (status == OperationStatus.Cancelled || status == OperationStatus.DelegateFailed)
{
return(new OperationResult <ChannelState>(status, new ChannelState(header)));
}
header.HeadNode = node.Next;
header.ActiveNodes -= 1;
ReturnSpaceToFreeList(offset, _sizeOfNode + node.Length, ref header);
Header.Write(_headerView, ref header);
return(new OperationResult <ChannelState>(status, new ChannelState(header)));
}
private async Task <OperationResult <ChannelState> > ReadAndSetEventsAsync(AsynchronousReadingOperation readingOperation)
{
var result = await((ReaderMemoryManager)_memoryManager).ReadAsync(readingOperation);
var channelState = result.Data;
if (channelState != null && channelState.MessagesCount == 0)
{
_hasMessagesEvent.Reset();
_noMessagesEvent.Set();
}
return(result);
}
