G.1.1 Error Status and Function Returns

The new DECthreads POSIX 1003.1c interface does not use errno. (Note that DECthreads still provides a thread- specific errno cell for use by libraries and application code, but the 1003.1c interface does not write to this cell.) If an error condition occurs, a pthread routine returns an integer value indicating the type of error. For example, a call to the Draft 4 implementation of pthread_cond_destroy that returned a -1 and set errno to EBUSY, now returns EBUSY as the routine return value in the current implementation. On successful completion, most pthread routines return a zero.