libstdc++: gthr.h Source File

libstdc++

gthr.h
1/* Threads compatibility routines for libgcc2. */
2/* Compile this one with gcc. */
3/* Copyright (C) 1997-2026 Free Software Foundation, Inc.
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify it under
8the terms of the GNU General Public License as published by the Free
9Software Foundation; either version 3, or (at your option) any later
10version.
11
12GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13WARRANTY; without even the implied warranty of MERCHANTABILITY or
14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15for more details.
16
17Under Section 7 of GPL version 3, you are granted additional
18permissions described in the GCC Runtime Library Exception, version
193.1, as published by the Free Software Foundation.
20
21You should have received a copy of the GNU General Public License and
22a copy of the GCC Runtime Library Exception along with this program;
23see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24<http://www.gnu.org/licenses/>. */
25
26#ifndef _GLIBCXX_GCC_GTHR_H
27#define _GLIBCXX_GCC_GTHR_H
28
29#ifndef _GLIBCXX_HIDE_EXPORTS
30#pragma GCC visibility push(default)
31#endif
32
33/* If this file is compiled with threads support, it must
34 #define __GTHREADS 1
35 to indicate that threads support is present. Also it has define
36 function
37 int __gthread_active_p ()
38 that returns 1 if thread system is active, 0 if not.
39
40 The threads interface must define the following types:
41 __gthread_key_t
42 __gthread_once_t
43 __gthread_mutex_t
44 __gthread_recursive_mutex_t
45
46 The threads interface must define the following macros:
47
48 __GTHREAD_ONCE_INIT
49 to initialize __gthread_once_t
50 __GTHREAD_MUTEX_INIT
51 to initialize __gthread_mutex_t to get a fast
52 non-recursive mutex.
53 __GTHREAD_MUTEX_INIT_FUNCTION
54 to initialize __gthread_mutex_t to get a fast
55 non-recursive mutex.
56 Define this to a function which looks like this:
57 void __GTHREAD_MUTEX_INIT_FUNCTION (__gthread_mutex_t *)
58 Some systems can't initialize a mutex without a
59 function call. Don't define __GTHREAD_MUTEX_INIT in this case.
60 __GTHREAD_RECURSIVE_MUTEX_INIT
61 __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION
62 as above, but for a recursive mutex.
63
64 The threads interface must define the following static functions:
65
66 int __gthread_once (__gthread_once_t *once, void (*func) ())
67
68 int __gthread_key_create (__gthread_key_t *keyp, void (*dtor) (void *))
69 int __gthread_key_delete (__gthread_key_t key)
70
71 void *__gthread_getspecific (__gthread_key_t key)
72 int __gthread_setspecific (__gthread_key_t key, const void *ptr)
73
74 int __gthread_mutex_destroy (__gthread_mutex_t *mutex);
75 int __gthread_recursive_mutex_destroy (__gthread_recursive_mutex_t *mutex);
76
77 int __gthread_mutex_lock (__gthread_mutex_t *mutex);
78 int __gthread_mutex_trylock (__gthread_mutex_t *mutex);
79 int __gthread_mutex_unlock (__gthread_mutex_t *mutex);
80
81 int __gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *mutex);
82 int __gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *mutex);
83 int __gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex);
84
85 The following are supported in POSIX threads only. They are required to
86 fix a deadlock in static initialization inside libsupc++. The header file
87 gthr-posix.h defines a symbol __GTHREAD_HAS_COND to signify that these extra
88 features are supported.
89
90 Types:
91 __gthread_cond_t
92
93 Macros:
94 __GTHREAD_COND_INIT
95 __GTHREAD_COND_INIT_FUNCTION
96
97 Interface:
98 int __gthread_cond_broadcast (__gthread_cond_t *cond);
99 int __gthread_cond_wait (__gthread_cond_t *cond, __gthread_mutex_t *mutex);
100 int __gthread_cond_wait_recursive (__gthread_cond_t *cond,
101 __gthread_recursive_mutex_t *mutex);
102
103 All functions returning int should return zero on success or the error
104 number. If the operation is not supported, -1 is returned.
105
106 If the following are also defined, you should
107 #define __GTHREADS_CXX0X 1
108 to enable the c++0x thread library.
109
110 Types:
111 __gthread_t
112 __gthread_time_t
113
114 Interface:
115 int __gthread_create (__gthread_t *thread, void *(*func) (void*),
116 void *args);
117 int __gthread_join (__gthread_t thread, void **value_ptr);
118 int __gthread_detach (__gthread_t thread);
119 int __gthread_equal (__gthread_t t1, __gthread_t t2);
120 __gthread_t __gthread_self (void);
121 int __gthread_yield (void);
122
123 int __gthread_mutex_timedlock (__gthread_mutex_t *m,
124 const __gthread_time_t *abs_timeout);
125 int __gthread_recursive_mutex_timedlock (__gthread_recursive_mutex_t *m,
126 const __gthread_time_t *abs_time);
127
128 int __gthread_cond_signal (__gthread_cond_t *cond);
129 int __gthread_cond_timedwait (__gthread_cond_t *cond,
130 __gthread_mutex_t *mutex,
131 const __gthread_time_t *abs_timeout);
132
133*/
134
135#if __GXX_WEAK__
136/* The pe-coff weak support isn't fully compatible to ELF's weak.
137 For static libraries it might would work, but as we need to deal
138 with shared versions too, we disable it for mingw-targets. */
139#ifdef __MINGW32__
140#undef _GLIBCXX_GTHREAD_USE_WEAK
141#define _GLIBCXX_GTHREAD_USE_WEAK 0
142#endif
143
144#ifdef _GLIBCXX___GLIBC_PREREQ
145#if _GLIBCXX___GLIBC_PREREQ(2, 34) && !defined(_GLIBCXX___gnu_GLIBCXX__hurd_GLIBCXX___)
146/* glibc 2.34 and later has all pthread_* APIs inside of libc,
147 no need to link separately with -lpthread. */
148#undef _GLIBCXX_GTHREAD_USE_WEAK
149#define _GLIBCXX_GTHREAD_USE_WEAK 0
150#endif
151#endif
152
153#ifndef _GLIBCXX_GTHREAD_USE_WEAK
154#define _GLIBCXX_GTHREAD_USE_WEAK 1
155#endif
156#endif
157#include <bits/gthr-default.h>
158
159#ifndef _GLIBCXX_HIDE_EXPORTS
160#pragma GCC visibility pop
161#endif
162
163#endif /* ! _GLIBCXX_GCC_GTHR_H */