1 /* pthread_mutex_trylock. Hurd version.
2 Copyright (C) 2016-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #include <pthread.h>
20 #include <stdlib.h>
21 #include <assert.h>
22 #include <pt-internal.h>
23 #include "pt-mutex.h"
24 #include <hurdlock.h>
25
26 int
__pthread_mutex_trylock(pthread_mutex_t * mtxp)27 __pthread_mutex_trylock (pthread_mutex_t *mtxp)
28 {
29 struct __pthread *self;
30 int ret;
31
32 switch (MTX_TYPE (mtxp))
33 {
34 case PT_MTX_NORMAL:
35 ret = lll_trylock (mtxp->__lock);
36 if (ret)
37 ret = EBUSY;
38 break;
39
40 case PT_MTX_RECURSIVE:
41 self = _pthread_self ();
42 if (mtx_owned_p (mtxp, self, mtxp->__flags))
43 {
44 if (__glibc_unlikely (mtxp->__cnt + 1 == 0))
45 return EAGAIN;
46
47 ++mtxp->__cnt;
48 ret = 0;
49 }
50 else if ((ret = lll_trylock (mtxp->__lock)) == 0)
51 {
52 mtx_set_owner (mtxp, self, mtxp->__flags);
53 mtxp->__cnt = 1;
54 }
55 else
56 ret = EBUSY;
57
58 break;
59
60 case PT_MTX_ERRORCHECK:
61 self = _pthread_self ();
62 if ((ret = lll_trylock (mtxp->__lock)) == 0)
63 mtx_set_owner (mtxp, self, mtxp->__flags);
64 else
65 ret = EBUSY;
66 break;
67
68 case PT_MTX_NORMAL | PTHREAD_MUTEX_ROBUST:
69 case PT_MTX_RECURSIVE | PTHREAD_MUTEX_ROBUST:
70 case PT_MTX_ERRORCHECK | PTHREAD_MUTEX_ROBUST:
71 self = _pthread_self ();
72 ROBUST_LOCK (self, mtxp, lll_robust_trylock);
73 break;
74
75 default:
76 ret = EINVAL;
77 break;
78 }
79
80 return ret;
81 }
82
83 hidden_def (__pthread_mutex_trylock)
84 strong_alias (__pthread_mutex_trylock, _pthread_mutex_trylock)
85 weak_alias (__pthread_mutex_trylock, pthread_mutex_trylock)
86