static void pse51_shm_put(pse51_shm_t * shm, unsigned dec)
{
spl_t s;
xnlock_get_irqsave(&nklock, s);
while (dec--)
pse51_node_put(&shm->nodebase);
if (pse51_node_removed_p(&shm->nodebase)) {
xnlock_put_irqrestore(&nklock, s);
pse51_shm_destroy(shm, 0);
xnfree(shm);
} else
xnlock_put_irqrestore(&nklock, s);
}
/**
* Close a named semaphore.
*
* This service closes the semaphore @a sm. The semaphore is destroyed only when
* unlinked with a call to the sem_unlink() service and when each call to
* sem_open() matches a call to this service.
*
* When a semaphore is destroyed, the memory it used is returned to the system
* heap, so that further references to this semaphore are not guaranteed to
* fail, as is the case for unnamed semaphores.
*
* This service fails if @a sm is an unnamed semaphore.
*
* @param sm the semaphore to be closed.
*
* @retval 0 on success;
* @retval -1 with @a errno set if:
* - EINVAL, the semaphore @a sm is invalid or is an unnamed semaphore.
*
* @see
* <a href="http://www.opengroup.org/onlinepubs/000095399/functions/sem_close.html">
* Specification.</a>
*
*/
int sem_close(sem_t * sm)
{
struct __shadow_sem *shadow = &((union __xeno_sem *)sm)->shadow_sem;
nsem_t *named_sem;
spl_t s;
int err;
xnlock_get_irqsave(&nklock, s);
if (shadow->magic != PSE51_NAMED_SEM_MAGIC
|| shadow->sem->magic != PSE51_SEM_MAGIC) {
err = EINVAL;
goto error;
}
named_sem = sem2named_sem(shadow->sem);
err = pse51_node_put(&named_sem->nodebase);
if (err)
goto error;
if (pse51_node_removed_p(&named_sem->nodebase)) {
/* unlink was called, and this semaphore is no longer referenced. */
pse51_mark_deleted(shadow);
pse51_mark_deleted(&named_sem->sembase);
xnlock_put_irqrestore(&nklock, s);
sem_destroy_inner(&named_sem->sembase, pse51_kqueues(1));
} else if (!pse51_node_ref_p(&named_sem->nodebase)) {
/* this semaphore is no longer referenced, but not unlinked. */
pse51_mark_deleted(shadow);
xnlock_put_irqrestore(&nklock, s);
} else
xnlock_put_irqrestore(&nklock, s);
return 0;
error:
xnlock_put_irqrestore(&nklock, s);
thread_set_errno(err);
return -1;
}
