It seems we found a weird bug with boost interprocess, some internal problem on the scoped_lock is generating a deadlock. A simple correct usage like void foo() { scoped_lock lock(amutex); ..... } is producing the deadlock when running 100 concurrent processes after changing to void foo() { amutex.lock(); ..... amutex.unlock(); } the problem disappeared the code on scoped_lock looks correct, and works just fine with a lower load, so, I guess this is something coming from the compiler, which is gcc 4.4.7 under linux did anyone get similar problems? thanks