NAME

       sem_destroy - destroy an unnamed semaphore

SYNOPSIS

       #include <semaphore.h>

       int sem_destroy(sem_t *sem);

       Link with -pthread.

DESCRIPTION

       sem_destroy() destroys the unnamed semaphore at the address pointed to by sem.

       Only  a  semaphore  that  has  been  initialized  by sem_init(3) should be destroyed using
       sem_destroy().

       Destroying a semaphore that other processes  or  threads  are  currently  blocked  on  (in
       sem_wait(3)) produces undefined behavior.

       Using  a semaphore that has been destroyed produces undefined results, until the semaphore
       has been reinitialized using sem_init(3).

RETURN VALUE

       sem_destroy() returns 0 on success; on error, -1 is returned, and errno is set to indicate
       the error.

ERRORS

       EINVAL sem is not a valid semaphore.

CONFORMING TO

       POSIX.1-2001.

NOTES

       An  unnamed semaphore should be destroyed with sem_destroy() before the memory in which it
       is located is deallocated.  Failure to do this  can  result  in  resource  leaks  on  some
       implementations.

SEE ALSO

       sem_init(3), sem_post(3), sem_wait(3), sem_overview(7)

COLOPHON

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       project,    and    information    about    reporting    bugs,    can    be    found     at
       http://www.kernel.org/doc/man-pages/.