]>
Commit | Line | Data |
---|---|---|
b168057a | 1 | /* Copyright (C) 2002-2015 Free Software Foundation, Inc. |
76a50749 UD |
2 | This file is part of the GNU C Library. |
3 | Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. | |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
59ba27a6 PE |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
76a50749 | 18 | |
68a396e8 UD |
19 | #include <errno.h> |
20 | #include <search.h> | |
76a50749 | 21 | #include <sys/mman.h> |
68a396e8 UD |
22 | #include "semaphoreP.h" |
23 | ||
24 | ||
25 | /* Global variables to parametrize the walk function. This works | |
26 | since we always have to use locks. And we have to use the twalk | |
27 | function since the entries are not sorted wrt the mapping | |
28 | address. */ | |
29 | static sem_t *the_sem; | |
30 | static struct inuse_sem *rec; | |
31 | ||
32 | static void | |
33 | walker (const void *inodep, const VISIT which, const int depth) | |
34 | { | |
35 | struct inuse_sem *nodep = *(struct inuse_sem **) inodep; | |
36 | ||
37 | if (nodep->sem == the_sem) | |
38 | rec = nodep; | |
39 | } | |
76a50749 UD |
40 | |
41 | ||
42 | int | |
9d46370c | 43 | sem_close (sem_t *sem) |
76a50749 | 44 | { |
68a396e8 UD |
45 | int result = 0; |
46 | ||
47 | /* Get the lock. */ | |
e51deae7 | 48 | lll_lock (__sem_mappings_lock, LLL_PRIVATE); |
68a396e8 UD |
49 | |
50 | /* Locate the entry for the mapping the caller provided. */ | |
51 | rec = NULL; | |
52 | the_sem = sem; | |
d051b143 | 53 | __twalk (__sem_mappings, walker); |
68a396e8 UD |
54 | if (rec != NULL) |
55 | { | |
56 | /* Check the reference counter. If it is going to be zero, free | |
57 | all the resources. */ | |
58 | if (--rec->refcnt == 0) | |
59 | { | |
60 | /* Remove the record from the tree. */ | |
d051b143 | 61 | (void) __tdelete (rec, &__sem_mappings, __sem_search); |
68a396e8 UD |
62 | |
63 | result = munmap (rec->sem, sizeof (sem_t)); | |
64 | ||
65 | free (rec); | |
66 | } | |
67 | } | |
68 | else | |
69 | { | |
70 | /* This is no valid semaphore. */ | |
71 | result = -1; | |
72 | __set_errno (EINVAL); | |
73 | } | |
74 | ||
75 | /* Release the lock. */ | |
e51deae7 | 76 | lll_unlock (__sem_mappings_lock, LLL_PRIVATE); |
68a396e8 UD |
77 | |
78 | return result; | |
76a50749 | 79 | } |