private OperationResult <ChannelState> ReadWithTimeout(ReadingOperation readingOperation, TimeSpan timeout)
{
ThrowIfDisposed();
bool gainedExclusiveAccess = false;
try
{
gainedExclusiveAccess = _exclusiveAccessSemaphore.WaitOne(timeout);
if (!gainedExclusiveAccess)
{
return(new OperationResult <ChannelState>(OperationStatus.Timeout, null));
}
return(ReadAndSetEvents(readingOperation));
}
finally
{
if (gainedExclusiveAccess)
{
_exclusiveAccessSemaphore.Release();
}
}
}
public OperationResult <ChannelState> Read(ReadingOperation 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 = readingOperation.Read(_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 OperationResult <ChannelState> ReadAndSetEvents(ReadingOperation readingOperation)
{
var result = ((ReaderMemoryManager)_memoryManager).Read(readingOperation);
var channelState = result.Data;
if (channelState != null && channelState.MessagesCount == 0)
{
_hasMessagesEvent.Reset();
_noMessagesEvent.Set();
}
return(result);
}
private OperationResult <ChannelState> ReadWithCancellation(ReadingOperation readingOperation, CancellationToken cancellationToken, TimeSpan timeout)
{
if (!cancellationToken.CanBeCanceled)
{
return(ReadWithTimeout(readingOperation, timeout));
}
ThrowIfDisposed();
bool gainedExclusiveAccess = false;
try
{
var index = WaitHandle.WaitAny(new[] { cancellationToken.WaitHandle, _exclusiveAccessSemaphore }, timeout);
if (index == 0)
{
return(new OperationResult <ChannelState>(OperationStatus.Cancelled, null));
}
if (index == WaitHandle.WaitTimeout)
{
return(new OperationResult <ChannelState>(OperationStatus.Timeout, null));
}
gainedExclusiveAccess = true;
return(ReadAndSetEvents(readingOperation));
}
finally
{
if (gainedExclusiveAccess)
{
_exclusiveAccessSemaphore.Release();
}
}
}
