php man page for sem_destroy

SEM_DESTROY(3)						     Linux Programmer's Manual						    SEM_DESTROY(3)

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.

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       +--------------+---------------+---------+
       |Interface     | Attribute     | Value	|
       +--------------+---------------+---------+
       |sem_destroy() | Thread safety | MT-Safe |
       +--------------+---------------+---------+
CONFORMING TO

       POSIX.1-2001, POSIX.1-2008.

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

       This page is part of release 4.15 of the Linux man-pages project.  A description of the project, information about reporting bugs, and  the
       latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

Linux								    2017-09-15							    SEM_DESTROY(3)