Abort a process during poskbak.

public class ProcessingClass
{
	/// <summary>
	/// Lock object to synchronize the _workerThread access.
	/// </summary>
	private static volatile object _lock = new object();

	/// <summary>
	/// The worker thread doing your stuff.
	/// </summary>
	private static Thread _workerThread;

	/// <summary>
	/// Method to start the processing.
	/// </summary>
	public void StartProcessing()
	{
		// first aquire a lock (that you can be sure you're the only one accessing the _workerThread property).
		lock (_lock)
		{
			if (_workerThread != null)
			{
				throw new NotSupportedException("The thread is already processing...");
			}

			// Instantiate the thread.
			_workerThread = new Thread(ProcessingMethod);

			// Start the processing.
			_workerThread.Start();
		}
	}

	/// <summary>
	/// Method to end the processing.
	/// </summary>
	public void EndProcess()
	{
		// first aquire a lock (that you can be sure you're the only one accessing the _workerThread property).
		lock (_lock)
		{
			if (_workerThread == null)
			{
				throw new NotSupportedException("The thread is not processing anything.");
			}

			// Join the thread and give him 1000ms to terminate
			_workerThread.Join(1000);
				
			// Thread terminated completely.
		}
	}

	/// <summary>
	/// The processing method itself.
	/// </summary>
	public void ProcessingMethod()
	{
		// do some stuff in it...
		Thread.Sleep(10000);
	}
}