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-rw-r--r--libpthread/nptl/sem_close.c81
1 files changed, 81 insertions, 0 deletions
diff --git a/libpthread/nptl/sem_close.c b/libpthread/nptl/sem_close.c
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+++ b/libpthread/nptl/sem_close.c
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+/* 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;
+}