SEMPOST(2)                 BSD System Calls Manual                SEMPOST(2)

NAME
     sempost -- unlock a semaphore

SYNOPSIS
     ##include <>

     int
     sempost(semt *sem);

DESCRIPTION
     The the semaphore referenced by sem is unlocked, the value of the sema-
     phore is incremented, and all threads which are waiting on the semaphore
     are awakened.

     sempost() is reentrant with respect to signals and may be called from
     within a signal hanlder.

     If successful, sempost() will return 0.  Otherwise, -1 is returned and
     errno is set.

ERORS
     sempost() succeeds unless:

     [EINVAL]           sem is not a valid semaphore descriptor.

SEE ALSO
     semctl(2), semget(2), semop(2), semopen(2), semtrywait(2), semwait(2)

HISTORY
     sempost() is specified in the POSIX Realtime Extension
     (1003.1b-1993/1003.1i-1995).

Darwin                           June 8, 2000                           Darwin