sem_close(3C)sem_close(3C)NAMEsem_close - close a posix named semaphore
SYNOPSIS
#include <semaphore.h>
int sem_close (sem_t *sem);
DESCRIPTIONsem_close closes the connection to the named semaphore located at address
sem. The address sem may reside anywhere in the calling processes
address space, but the process must have read and write access to sem.
If multiple threads within a common process (i.e., sprocs, pthreads) are
sharing sem, a single call to sem_close will close the named semaphore
for all threads within the calling process.
Once a named semaphore has been closed, subsequent operations on the
semaphore by the calling process will fail until the semaphore has been
reopened.
If the calling process was the last process to close the semaphore, and
the semaphore has been unlinked via sem_unlink, then the named semaphore
will cease to exist. Otherwise, the semaphore will persist.
sem_close will fail if the following is true:
[EINVAL] The semaphore located at address sem is not a valid posix
named semaphore.
SEE ALSOsem_destroy(3C), sem_init(3C), sem_getvalue(3C), sem_post(3C),
sem_wait(3C), sem_trywait(3C), sem_open(3C), sem_unlink(3C),
shm_open(3C), mmap(3C)DIAGNOSTICS
Upon successful completion, a value of 0 is returned to the calling
process. Otherwise, a value of -1 is returned and errno is set to
indicate the error.
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