/// <summary>
/// Shuts the processing pipeline down (base class specific part).
/// This method must not throw exceptions.
/// </summary>
internal override void OnShutdownBase()
{
// tell the processing thread to terminate
// (it will try to process the last messages and exit)
mTerminateProcessingTask = true;
mAsyncProcessingCancellationTokenSource?.CancelAfter(mShutdownTimeout);
mTriggerAsyncProcessingEvent?.Set();
mAsyncProcessingTask?.Wait();
// the processing task should have completed its work
Debug.Assert(mAsyncProcessingTask == null || mAsyncProcessingTask.IsCompleted);
// the stack should be empty now...
Debug.Assert(mAsyncProcessingMessageStack == null || mAsyncProcessingMessageStack.UsedItemCount == 0);
// clean up processing thread related stuff
mAsyncContextThread?.Join();
mAsyncProcessingCancellationTokenSource?.Dispose();
mAsyncContextThread = null;
mAsyncProcessingTask = null;
mAsyncProcessingCancellationTokenSource = null;
mAsyncProcessingMessageStack = null;
// perform pipeline stage specific cleanup
try
{
OnShutdown();
}
catch (Exception ex)
{
// swallow exception to avoid crashing the application, if the exception is not handled properly
Debug.Fail("The pipeline stage failed shutting down.", ex.ToString());
}
}
/// <summary>
/// Initializes the processing pipeline stage (base class specific part).
/// </summary>
internal override void OnInitializeBase()
{
try
{
// set up asynchronous processing
mAsyncProcessingMessageStack = new LocklessStack <LocalLogMessage>(mMessageQueueSize, false);
mTriggerAsyncProcessingEvent = new AsyncAutoResetEvent(false);
mAsyncProcessingCancellationTokenSource = new CancellationTokenSource();
mTerminateProcessingTask = false;
mAsyncContextThread = new AsyncContextThread();
mAsyncProcessingTask = mAsyncContextThread.Factory.Run(ProcessingTask);
// Perform pipeline stage specific initialization
OnInitialize();
}
catch (Exception)
{
Shutdown();
throw;
}
}