WaitForMultipleObjects

[Neil Croft]

Working away from home for a few days and I'm miles from my own machines (and notes ). Quick question for the fastest help I know


Got a program that starts two worker threads, mythread1 and mythread2, Both run and do a half a task each so they finish around the same time. From the help files I get the impression I can use WaitForMultipleObjects to continue execution of the main thread once they both return. How does it work? ie, what's the syntax? Currently I'm using a sleepy while/wend loop with Thread Status monitoring the two variables holding the thread ids, ie.

(main program)
        THREAD CREATE MyThread1(tc) TO e
        THREAD CREATE MyThread2(tc) TO f
        THREAD STATUS e TO a
        THREAD STATUS f TO b
        WHILE a=259 OR b=259
            SLEEP 5
            THREAD STATUS e TO a
            THREAD STATUS f TO b
        WEND
(main program cotinues, hopefully when the threads have completed)

Thanks in advance.

[Michael Mattias]

Doc:

DWORD WaitForMultipleObjects(
  DWORD nCount,
  const HANDLE* lpHandles,
  BOOL bWaitAll,
  DWORD dwMilliseconds
);

Applied:

  REDIM    hThread (1)
  THREAD CREATE MyThread1(tc) TO hthread(0)
  THREAD CREATE MyThread2(tc) TO hThread(1)
  WaitForMultipleObjects 2, BYVAL VARPTR (hThread(0)), %TRUE, %INFINITE
  'program continues here when both thread functions have completed
  THREAD STATUS hThread(0) to Result1   ' get thread functions' return codes
  THREAD STATUS hThread(1) to Result2 
  THREAD CLOSE hThread(0) to Dummy     ' done with handles
  THREAD CLOSE hThread(1) to Dummy

More examples of WFMO in Source Code Forum:
Waitable Timer Object Demo June 2005

Terminate Worker Threads Using Windows Events (and Using Thread Local Storage) Demo Dec 23 2005

GUI + Worker Thread + Abort Demo 11-24-07

MCM

[Neil Croft]

Thank you Michael. Just what I needed.