c library function to get number of active threads

Question

Hi everybody,

I'm developing a multi threaded Unix application in C. Is there a simple way to get the count of the number of simultaneously active threads? I don't want to have to write the code to keep track of the number of active thread if it already can be done for me by the library! :-)

I'm using POSIX pthreads, and I'm trying to write as portable as possible code for Unix and Unix-like systems.

Answer 1

No, not in pthreads per se. POSIX Threads tries to specify only primitives or basic utility constructs, and considers even pthread_join a convenience function, not a primitive.

Certain libraries may offer non-portable solutions (look for _np in the name on HP-UX, for instance), but for pthreads per se, you're on your own.

Answer 2

You could I guess keep a count of it in the constructor/destructor but make sure you handle it concurrently as to avoid race conditions.