1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
|
/* 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 "pthreadP.h"
#include <lowlevellock.h>
int
__pthread_mutex_trylock (mutex)
pthread_mutex_t *mutex;
{
struct pthread *pd = THREAD_SELF;
switch (__builtin_expect (mutex->__data.__kind, PTHREAD_MUTEX_TIMED_NP))
{
/* Recursive mutex. */
case PTHREAD_MUTEX_RECURSIVE_NP:
/* Check whether we already hold the mutex. */
if (mutex->__data.__owner == pd)
{
/* Just bump the counter. */
if (__builtin_expect (mutex->__data.__count + 1 == 0, 0))
/* Overflow of the counter. */
return EAGAIN;
++mutex->__data.__count;
return 0;
}
if (lll_mutex_trylock (mutex->__data.__lock) == 0)
{
/* Record the ownership. */
mutex->__data.__owner = pd;
mutex->__data.__count = 1;
return 0;
}
break;
case PTHREAD_MUTEX_ERRORCHECK_NP:
/* Error checking mutex. We do not check for deadlocks. */
default:
/* Correct code cannot set any other type. */
case PTHREAD_MUTEX_TIMED_NP:
case PTHREAD_MUTEX_ADAPTIVE_NP:
/* Normal mutex. */
if (lll_mutex_trylock (mutex->__data.__lock) == 0)
{
/* Record the ownership. */
mutex->__data.__owner = pd;
return 0;
}
}
return EBUSY;
}
strong_alias (__pthread_mutex_trylock, pthread_mutex_trylock)
|
