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sem_destroy

Section: C Library Functions (3)
Updated: 202-0-08
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NAME

sem_destroy - destroy an unnamed semaphore

LIBRARY

POSIX threads library (libpthread,~-lpthread)

SYNOPSIS

#include <semaphore.h>
int sem_destroy(sem_t *sem);

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	M-Safe

STANDARDS

POSIX.-2008.

HISTORY

POSIX.-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.