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
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
|
/* Copyright (C) 2005-2019 Free Software Foundation, Inc.
Contributed by Richard Henderson <rth@redhat.com>.
This file is part of the GNU Offloading and Multi Processing Library
(libgomp).
Libgomp is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
Libgomp 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 General Public License for
more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
/* This file handles the CRITICAL construct. */
#include "libgomp.h"
#include <stdlib.h>
static gomp_mutex_t default_lock;
void
GOMP_critical_start (void)
{
/* There is an implicit flush on entry to a critical region. */
__atomic_thread_fence (MEMMODEL_RELEASE);
gomp_mutex_lock (&default_lock);
}
void
GOMP_critical_end (void)
{
gomp_mutex_unlock (&default_lock);
}
#ifndef HAVE_SYNC_BUILTINS
static gomp_mutex_t create_lock_lock;
#endif
void
GOMP_critical_name_start (void **pptr)
{
gomp_mutex_t *plock;
/* If a mutex fits within the space for a pointer, and is zero initialized,
then use the pointer space directly. */
if (GOMP_MUTEX_INIT_0
&& sizeof (gomp_mutex_t) <= sizeof (void *)
&& __alignof (gomp_mutex_t) <= sizeof (void *))
plock = (gomp_mutex_t *)pptr;
/* Otherwise we have to be prepared to malloc storage. */
else
{
plock = *pptr;
if (plock == NULL)
{
#ifdef HAVE_SYNC_BUILTINS
gomp_mutex_t *nlock = gomp_malloc (sizeof (gomp_mutex_t));
gomp_mutex_init (nlock);
plock = __sync_val_compare_and_swap (pptr, NULL, nlock);
if (plock != NULL)
{
gomp_mutex_destroy (nlock);
free (nlock);
}
else
plock = nlock;
#else
gomp_mutex_lock (&create_lock_lock);
plock = *pptr;
if (plock == NULL)
{
plock = gomp_malloc (sizeof (gomp_mutex_t));
gomp_mutex_init (plock);
__sync_synchronize ();
*pptr = plock;
}
gomp_mutex_unlock (&create_lock_lock);
#endif
}
}
gomp_mutex_lock (plock);
}
void
GOMP_critical_name_end (void **pptr)
{
gomp_mutex_t *plock;
/* If a mutex fits within the space for a pointer, and is zero initialized,
then use the pointer space directly. */
if (GOMP_MUTEX_INIT_0
&& sizeof (gomp_mutex_t) <= sizeof (void *)
&& __alignof (gomp_mutex_t) <= sizeof (void *))
plock = (gomp_mutex_t *)pptr;
else
plock = *pptr;
gomp_mutex_unlock (plock);
}
#if !GOMP_MUTEX_INIT_0
static void __attribute__((constructor))
initialize_critical (void)
{
gomp_mutex_init (&default_lock);
#ifndef HAVE_SYNC_BUILTINS
gomp_mutex_init (&create_lock_lock);
#endif
}
#endif
|
