mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-10 07:10:06 +00:00
82 lines
2.1 KiB
C
82 lines
2.1 KiB
C
/* Copyright (C) 2002-2020 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <errno.h>
|
|
#include <search.h>
|
|
#include <sys/mman.h>
|
|
#include "semaphoreP.h"
|
|
|
|
struct walk_closure
|
|
{
|
|
sem_t *the_sem;
|
|
struct inuse_sem *rec;
|
|
};
|
|
|
|
static void
|
|
walker (const void *inodep, VISIT which, void *closure0)
|
|
{
|
|
struct walk_closure *closure = closure0;
|
|
struct inuse_sem *nodep = *(struct inuse_sem **) inodep;
|
|
|
|
if (nodep->sem == closure->the_sem)
|
|
closure->rec = nodep;
|
|
}
|
|
|
|
|
|
int
|
|
sem_close (sem_t *sem)
|
|
{
|
|
int result = 0;
|
|
|
|
/* Get the lock. */
|
|
lll_lock (__sem_mappings_lock, LLL_PRIVATE);
|
|
|
|
/* Locate the entry for the mapping the caller provided. */
|
|
struct inuse_sem *rec;
|
|
{
|
|
struct walk_closure closure = { .the_sem = sem, .rec = NULL };
|
|
__twalk_r (__sem_mappings, walker, &closure);
|
|
rec = closure.rec;
|
|
}
|
|
if (rec != NULL)
|
|
{
|
|
/* Check the reference counter. If it is going to be zero, free
|
|
all the resources. */
|
|
if (--rec->refcnt == 0)
|
|
{
|
|
/* Remove the record from the tree. */
|
|
(void) __tdelete (rec, &__sem_mappings, __sem_search);
|
|
|
|
result = munmap (rec->sem, sizeof (sem_t));
|
|
|
|
free (rec);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* This is no valid semaphore. */
|
|
result = -1;
|
|
__set_errno (EINVAL);
|
|
}
|
|
|
|
/* Release the lock. */
|
|
lll_unlock (__sem_mappings_lock, LLL_PRIVATE);
|
|
|
|
return result;
|
|
}
|