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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, which this
     implementation is not capable of.

     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  The sem argument is no longer valid after	a successful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.

     [EPERM]		Unable to initialize a shared semaphore.

SEE ALSO
     sem_destroy(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'').

     This implementation does not support shared semaphores, and reports this
     fact by setting errno to EPERM.  This is perhaps a	stretch	of the inten-
     tion of POSIX, but	is compliant, with the caveat that sem_init() always
     reports a permissions error when an attempt to create a shared semaphore
     is	made.

FreeBSD	11.1		       February	15, 2000		  FreeBSD 11.1

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

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