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SEM_INIT(3)	       FreeBSD Library Functions Manual		   SEM_INIT(3)

NAME
     sem_init -- initialize an unnamed semaphore

LIBRARY
     Standard C	Library	(libc, -lc)

SYNOPSIS
     #include <semaphore.h>

     int
     sem_init(sem_t *sem, int pshared, unsigned	int value);

DESCRIPTION
     The sem_init() function initializes the unnamed semaphore pointed to by
     sem to have the value value.

     A non-zero	value for pshared specifies a shared semaphore that can	be
     used by multiple processes, the semaphore should be located in shared
     memory region (see	mmap(2), shm_open(2), and shmget(2)), any process hav-
     ing read and write	access to address sem can perform semaphore operations
     on	sem.

     Following a successful call to sem_init(),	sem can	be used	as an argument
     in	subsequent calls to sem_wait(3), sem_trywait(3), sem_post(3), and
     sem_destroy(3).  The sem argument is no longer valid after	a successful
     call to sem_destroy(3).

RETURN VALUES
     The sem_init() 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_init() function will fail if:

     [EINVAL]		The value argument exceeds SEM_VALUE_MAX.

     [ENOSPC]		Memory allocation error.

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

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

FreeBSD	11.1			January	9, 2010			  FreeBSD 11.1

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

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