Question

Can someone explain this code to me a little so I have a firmer grasp of exactly what is going on in it?

taskWrapper = XTThreadPool.DEFAULT_POOL.Run((System.Threading.ThreadStart)delegate()
{
    //Remote procedure execution and result processing code.
    //Some vars set in here are used after the Join() below.
}, true, true);

while (taskWrapper.Status == XTThreadPool.Task.STATUS.None)
{
    System.Threading.Thread.Sleep(10);
}

...

taskWrapper.Join();

It looks to me like a separate thread is being created and the remote procedure call is used within it. I’m a little hazy about the use of the delegate or the syntax of the taskWrapper object creation though.

Answer 1

Well it’s a little tricky without knowing what’s in the XTThreadPool class, but you could have a guess…

The chances are that this first bit…

taskWrapper = XTThreadPool.DEFAULT_POOL.Run((System.Threading.ThreadStart)delegate()
{
    //Remote procedure execution and result processing code.
    //Some vars set in here are used after the Join() below.
}, true, true);

…starts a thread running asynchronously and passes the method specified in the section where you’ve put comments. This is probably achieved by creating an instance of a Thread passing the method as a delegate to its constructor, and calling newThread.Start(), which starts execution on a new thread inside the application’s thread pool. The thread reference can then be used to check the status of that thread and see if it’s completed or not, which is probably what this section does:

while (taskWrapper.Status == XTThreadPool.Task.STATUS.None)
{
    System.Threading.Thread.Sleep(10);
}

This seems a bit strange to me. System.Threading.Thread accesses the current thread, not the thread started by the thread pool, and the Sleep method just means “do nothing”. So the current thread is waiting for the thread started by the taskWrapper instance to enter a status other than None. Now this is where it gets difficult because we don’t really know what taskWrapper is doing.

It is possible that actually it’s just waiting for the thread to complete execution, but then there would be no point having a separate thread, because the work might as well be done in place of the while loop above.

And then this:

taskWrapper.Join();

The line above could really do anything, like I say it depends on the implementation of whatever taskWrapper is. But based on the name I would guess it uses the the Thread.Join method, which basically causes the calling thread (this thread) to wait until the thread it’s called on (taskWrapper) has completed. However taskWrapper itself is not actually be a thread (based on the check for the value of the Status property above), more likely it’s just a wrapper around the thread.

I’ve completely guessed at this to be honest, it really could be doing anything. Without seeing the code for the XTThreadPool class and whatever DEFAULT_POOL is an instance of it’s going to be impossible to know for sure what’s happening.

On first inspection, if the code is doing what I’ve guessed above there is no point having another thread to do the work and no point having the while loop! The whole thing could be replaced with whatever’s in the method inside the call to Run.