|SEM_POST(3)||Library Functions Manual||SEM_POST(3)|
sem_post() function increments (unlocks) the semaphore pointed to by sem. If there are threads blocked on the semaphore when
sem_post() is called, then the highest priority thread that has been blocked the longest on the semaphore will be allowed to return from
sem_post() is signal-reentrant and may be
called within signal handlers.
sem_post() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error.
sem_post() will fail if:
sem_post() conforms to ISO/IEC 9945-1:1996 (“POSIX.1”).
|June 5, 2013||OpenBSD-current|