Thread problems on Mac OS X

[Ian Gough]

While trying out CC++ on Mac OS X, I found a problem that causes CC++ to recurse to death.

 

When creating a Thread object, a Semaphore (joinSem) gets instantiated. On this OS, the Semaphore constructor calls sem_init and if this fails, calls getException(), which instantiates a Thread, which creates a Semaphore, etc, causing the app to blow out the stack.

 

the following snippet from near line 130 in semaphore.cpp

 

Semaphore::Semaphore(size_t resource)
{
        if(sem_init(&_semaphore, 0, resource))
        {
                if(getException() == Thread::throwObject)
                        throw(this);

It seems that the sem_init is failing with ENOSYS, which means the sem_init function is not implemented on this platform, nor is sem_destroy(). It does seem though that sem_open() is implemented.

 

Perhaps the autotools need to test for correctly operating sem_init (one that doesn't return -1 all the time!) and use sem_open() in that case.

 

Regardless of whether this gets done or not though, the recursion issue should probably be addressed, even though it only occurs on a failed sem_init() call.