GG>> But how much difference will it make for a two threaded program ?

 PF> A lot.  DosEnterCritSec() _ALWAYS_ forces all other threads to stop.

 GG> But since there are only two threads that should not make any difference.

You are assuming that a sem always halts the other thread;  it doesn't.
DosEnterCritSec(), on the other hand,  always halts all other
threads,whether they need to be or not.

 GG> I do not know for sure but I think using 
 GG> DosEnterCritSec takes less overhead then using 
 GG> semaphores ?

That was true under OS/2 1.x,  but under OS/2 2.x sems are faster.


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