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SEM_POST(3)	       FreeBSD Library Functions Manual		   SEM_POST(3)

NAME
     sem_post -- increment (unlock) a semaphore

LIBRARY
     Standard C	Library	(libc, -lc)

SYNOPSIS
     #include <semaphore.h>

     int
     sem_post(sem_t *sem);

DESCRIPTION
     The 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	long-
     est on the	semaphore will be allowed to return from sem_wait().

     The sem_post() function is	signal-reentrant and may be called within sig-
     nal handlers.

RETURN VALUES
     The 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.

ERRORS
     The sem_post() function will fail if:

     [EINVAL]		The sem	argument points	to an invalid semaphore.

SEE ALSO
     sem_getvalue(3), sem_trywait(3), sem_wait(3), sem(4)

STANDARDS
     The sem_post() function conforms to ISO/IEC 9945-1:1996 (``POSIX.1'').

FreeBSD	10.1		       February	15, 2000		  FreeBSD 10.1

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | SEE ALSO | STANDARDS

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