private AsyncResult opAR; // The async result for the operation
/// <summary>
/// Constructs a work thread.
/// </summary>
public WorkerThread()
{
this.waitEvent = new AutoResetEvent(true);
this.wakeEvent = new AutoResetEvent(false);
this.method = null;
this.arg = null;
this.opAR = null;
this.thread = new Thread(new ThreadStart(ThreadLoop));
this.thread.Start();
}
/// <summary>
/// Invokes a method on the worker thread, blocking the current thread
/// until any operation already in progress complete. Once the operation
/// has been successfully submitted to the thread, this method will return
/// to allow the operation to complete asynchronously.
/// </summary>
/// <param name="method">The method delegate.</param>
/// <param name="arg">The method parameter.</param>
/// <param name="callback">The delegate to be called when the timer fires (or <c>null</c>).</param>
/// <param name="state">Application specific state.</param>
/// <returns>The <see cref="IAsyncResult" /> instance to be used to track the operation.</returns>
public IAsyncResult BeginInvoke(WorkerThreadMethod method, object arg, AsyncCallback callback, object state)
{
if (thread == null)
{
throw new InvalidOperationException("WorkerThread is closed.");
}
waitEvent.WaitOne();
this.method = method;
this.arg = arg;
this.opAR = new AsyncResult(null, callback, state);
this.opAR.Started();
wakeEvent.Set();
return(this.opAR);
}
/// <summary>
/// Invokes a method on the worker thread, blocking the current thread
/// until the operation completes.
/// </summary>
/// <param name="method">The method delegate.</param>
/// <param name="arg">The method parameter.</param>
/// <returns>The result returned by the delegate call.</returns>
/// <remarks>
/// <note>
/// Exceptions thrown in the method call on the worker thread
/// will be caught and rethrown on this thread.
/// </note>
/// </remarks>
public object Invoke(WorkerThreadMethod method, object arg)
{
var ar = BeginInvoke(method, arg, null, null);
return(EndInvoke(ar));
}
