On Jan 9, 2015, at 7:47 PM, Marcel Busse <strooka_ace@yahoo.de> wrote:

it is here:

http://www.opensource.apple.com/source/Libc/Libc-391/pthreads/

look into pthread_internals.h

This version of Libc hasn't been current since OS X 10.4 (Tiger).

With recent versions of OS X, the pthreads implementation is no longer in Libc and the new code has not been released.  In any case, there's also stuff in the kernel to support the userland implementation, and that's no longer open-source, either.

Regards,
Ken