diff options
Diffstat (limited to 'REORG.TODO/nptl/sem_close.c')
-rw-r--r-- | REORG.TODO/nptl/sem_close.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/REORG.TODO/nptl/sem_close.c b/REORG.TODO/nptl/sem_close.c new file mode 100644 index 0000000000..5049eadb1f --- /dev/null +++ b/REORG.TODO/nptl/sem_close.c @@ -0,0 +1,79 @@ +/* Copyright (C) 2002-2017 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 + <http://www.gnu.org/licenses/>. */ + +#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_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; +} |