🚀 go-pugleaf

"Daniel Stevenson" <d.stevenson@ocreage.com.au> wrote in message
news:415120dc@newsgroups.borland.com...

> I sort of understand what you are implying but I'm not sure how
> to stop my thread from being deadlocked.

For one thing, try using TThread's WaitFor() method instead of calling
WaitForSingleObject() directly.  If you need to call WaitForSingleObject()
then you should specify a timeout value and loop the call over and over.
That way, you can pump the message queue manually between each iteration of
the loop.

> As far as I know, the Synchronize function is fairly
> straight forward and should be able to be completed.

Synchronize() uses window messages internally.  In BCB 3-5, when
Synchronize() is called, it uses SendMessage() to pass the specified method
pointers to the the main thread to execute in a serialized manner.
SendMessage() does not return control to the caller until the message has
been processed.  In BCB6, the method pointers are placed into a global list
and then PostMessage() is called to notify the main thread that methods are
waiting to be executed.  The main thread runs through the list periodically,
calling the stored methods one at a time.

Either way, the main thread must process window messages in order to process
Sychronize() requests properly.  Synchronize() does not return control to
the thread until the request is finished.  If the main thread is blocked
waiting on a thread to terminate, it still needs to process new messages
while it is waiting, or else Synchronize() will block indefinately, and so
will anything that is waiting on the thread to terminate.


Gambit