| /* 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, LLL_PRIVATE); |
| |
| /* 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, LLL_PRIVATE); |
| |
| return result; |
| } |