private unsafe CancellationToken CreateDisconnectToken(ulong connectionId)
{
LogHelper.LogDebug(_logger, "CreateDisconnectToken", "Registering connection for disconnect for connection ID: " + connectionId);
// Create a nativeOverlapped callback so we can register for disconnect callback
var cts = new CancellationTokenSource();
var returnToken = cts.Token;
SafeNativeOverlapped nativeOverlapped = null;
var boundHandle = _requestQueue.BoundHandle;
nativeOverlapped = new SafeNativeOverlapped(boundHandle, boundHandle.AllocateNativeOverlapped(
(errorCode, numBytes, overlappedPtr) =>
{
LogHelper.LogDebug(_logger, "CreateDisconnectToken", "http.sys disconnect callback fired for connection ID: " + connectionId);
// Free the overlapped
nativeOverlapped.Dispose();
// Pull the token out of the list and Cancel it.
ConnectionCancellation token;
_connectionCancellationTokens.TryRemove(connectionId, out token);
try
{
cts.Cancel();
}
catch (AggregateException exception)
{
LogHelper.LogException(_logger, "CreateDisconnectToken Callback", exception);
}
},
null, null));
uint statusCode;
try
{
statusCode = HttpApi.HttpWaitForDisconnectEx(requestQueueHandle: _requestQueue.Handle,
connectionId: connectionId, reserved: 0, overlapped: nativeOverlapped);
}
catch (Win32Exception exception)
{
statusCode = (uint)exception.NativeErrorCode;
LogHelper.LogException(_logger, "CreateDisconnectToken", exception);
}
if (statusCode != UnsafeNclNativeMethods.ErrorCodes.ERROR_IO_PENDING &&
statusCode != UnsafeNclNativeMethods.ErrorCodes.ERROR_SUCCESS)
{
// We got an unknown result, assume the connection has been closed.
nativeOverlapped.Dispose();
ConnectionCancellation ignored;
_connectionCancellationTokens.TryRemove(connectionId, out ignored);
LogHelper.LogDebug(_logger, "HttpWaitForDisconnectEx", new Win32Exception((int)statusCode));
cts.Cancel();
}
if (statusCode == UnsafeNclNativeMethods.ErrorCodes.ERROR_SUCCESS && HttpSysListener.SkipIOCPCallbackOnSuccess)
{
// IO operation completed synchronously - callback won't be called to signal completion
nativeOverlapped.Dispose();
ConnectionCancellation ignored;
_connectionCancellationTokens.TryRemove(connectionId, out ignored);
cts.Cancel();
}
return(returnToken);
}