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SEM_INIT(3)                Library Functions Manual                SEM_INIT(3)

NAME
     sem_init - initialize an unnamed semaphore

LIBRARY
     POSIX Real-time Library (librt, -lrt)

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.

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  sem is no longer valid after a successful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

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
     sem_init() will fail if:

     [EINVAL]           value exceeds SEM_VALUE_MAX.

     [ENOSPC]           There was memory allocation error, or the limit on
                        available semaphores (SEM_NSEMS_MAX) has been
                        exceeded.

     [EPERM]            Unable to initialize a shared semaphore.

SEE ALSO
     sem_destroy(3), sem_post(3), sem_timedwait(3), sem_trywait(3),
     sem_wait(3)

STANDARDS
     sem_init() conforms to ISO/IEC 9945-1:1996 ("POSIX.1").

NetBSD 10.99                   February 21, 2019                  NetBSD 10.99