issue with Threadsafe singleton with semaphore

Question

I have written a simple singleton application.

The following is my sample main class

// ThreadsafeSingletonUsingSemaphore.cpp : Defines the entry poi         


        

Answer 1

The problem is that call to WaitForMultipleObjects handles up to MAXIMUM_WAIT_OBJECTS which, at least in Visual Studio 2017, is 64.

Notice how your call to WaitForMultipleObjects to join threads returns WAIT_FAILED.

In order to wait for more objects one should, according to the documentation:

To wait on more than MAXIMUM_WAIT_OBJECTS handles, use one of the following methods:

• Create a thread to wait on MAXIMUM_WAIT_OBJECTS handles, then wait on that thread plus the other handles. Use this technique to break the handles into groups of MAXIMUM_WAIT_OBJECTS.
• Call RegisterWaitForSingleObject to wait on each handle. A wait thread from the thread pool waits on MAXIMUM_WAIT_OBJECTS registered objects and assigns a worker thread after the object is signaled or the time-out interval expires.