mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-22 19:00:07 +00:00
82 lines
2.2 KiB
C
82 lines
2.2 KiB
C
/* Copyright (C) 2002, 2003 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, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA. */
|
|
|
|
#include <errno.h>
|
|
#include <search.h>
|
|
#include <sys/mman.h>
|
|
#include "semaphoreP.h"
|
|
|
|
|
|
/* Global variables to parametrize the walk function. This works
|
|
since we always have to use locks. And we have to use the twalk
|
|
function since the entries are not sorted wrt the mapping
|
|
address. */
|
|
static sem_t *the_sem;
|
|
static struct inuse_sem *rec;
|
|
|
|
static void
|
|
walker (const void *inodep, const VISIT which, const int depth)
|
|
{
|
|
struct inuse_sem *nodep = *(struct inuse_sem **) inodep;
|
|
|
|
if (nodep->sem == the_sem)
|
|
rec = nodep;
|
|
}
|
|
|
|
|
|
int
|
|
sem_close (sem)
|
|
sem_t *sem;
|
|
{
|
|
int result = 0;
|
|
|
|
/* Get the lock. */
|
|
lll_lock (__sem_mappings_lock);
|
|
|
|
/* Locate the entry for the mapping the caller provided. */
|
|
rec = NULL;
|
|
the_sem = sem;
|
|
twalk (__sem_mappings, walker);
|
|
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);
|
|
|
|
return result;
|
|
}
|