sem_destroy.2 (2010 09)

s
sem_destroy(2) sem_destroy(2)
NAME
sem_destroy - destroy an unnamed POSIX semaphore
SYNOPSIS
#include <sys/semaphore.h>
int sem_destroy(sem_t *sem);
DESCRIPTION
sem_destroy()
is used to destroy an unnamed semaphore. A successful call to
sem_destroy() will
invalidate the unnamed semaphore referred to by sem and removes all descriptors referencing it. The
semaphore should have been created by a previous call to
sem_init() and there should not be any
processes blocked on it.
To use this function, link in the realtime library by specifying
-lrt on the compiler or linker command
line.
EXAMPLES
The following call to
sem_destroy()
will destroy an unnamed semaphore referred to by sem and
remove all descriptors referencing it.
sem_destroy(sem);
RETURN VALUE
If the semaphore was destroyed and the descriptors referencing it were removed, sem_destroy()
returns 0 to the caller.
If the semaphore could not be destroyed, the call returns -1 and sets
errno to indicate the error.
ERRORS
sem_destroy() fails and does not perform the requested operation if any of the following conditions
are encountered:
[EBUSY] There are threads currently blocked on the semaphore or there are outstanding
locks held on the semaphore.
[EINVAL] The argument sem is not a valid unnamed semaphore.
SEE ALSO
sem_init(2), sem_open(2), <semaphore.h>.
STANDARDS CONFORMANCE
sem_destroy(): POSIX
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