aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/pthread/threads.h
blob: 860d597d96250a25d9f76be2fd869183f4b6550a (plain)
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
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
/* ISO C11 Standard: 7.26 - Thread support library  <threads.h>.
   Copyright (C) 2018-2023 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   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, see
   <https://www.gnu.org/licenses/>.  */

#ifndef _THREADS_H
#define _THREADS_H	1

#include <features.h>
#include <time.h>

__BEGIN_DECLS

#include <bits/thread-shared-types.h>
#include <bits/types/struct_timespec.h>

#if (!defined __STDC_VERSION__				\
     || __STDC_VERSION__ <= 201710L			\
     || !__GNUC_PREREQ (13, 0)) && !defined __cplusplus
# define thread_local _Thread_local
#endif

#define TSS_DTOR_ITERATIONS 4
typedef __tss_t tss_t;
typedef void (*tss_dtor_t) (void*);

typedef __thrd_t thrd_t;
typedef int (*thrd_start_t) (void*);

/* Exit and error codes.  */
enum
{
  thrd_success  = 0,
  thrd_busy     = 1,
  thrd_error    = 2,
  thrd_nomem    = 3,
  thrd_timedout = 4
};

/* Mutex types.  */
enum
{
  mtx_plain     = 0,
  mtx_recursive = 1,
  mtx_timed     = 2
};

typedef __once_flag once_flag;
#define ONCE_FLAG_INIT __ONCE_FLAG_INIT

typedef union
{
  char __size[__SIZEOF_PTHREAD_MUTEX_T];
  long int __align __LOCK_ALIGNMENT;
} mtx_t;

typedef union
{
  char __size[__SIZEOF_PTHREAD_COND_T];
  __extension__ long long int __align __LOCK_ALIGNMENT;
} cnd_t;

/* Threads functions.  */

/* Create a new thread executing the function __FUNC.  Arguments for __FUNC
   are passed through __ARG.  If succesful, __THR is set to new thread
   identifier.  */
extern int thrd_create (thrd_t *__thr, thrd_start_t __func, void *__arg);

/* Check if __LHS and __RHS point to the same thread.  */
extern int thrd_equal (thrd_t __lhs, thrd_t __rhs);

/* Return current thread identifier.  */
extern thrd_t thrd_current (void);

/* Block current thread execution for at least the time pointed by
   __TIME_POINT.  The current thread may resume if receives a signal.  In
   that case, if __REMAINING is not NULL, the remaining time is stored in
   the object pointed by it.  */
#ifndef __USE_TIME_BITS64
extern int thrd_sleep (const struct timespec *__time_point,
		       struct timespec *__remaining);
#else
# ifdef __REDIRECT
extern int __REDIRECT (thrd_sleep, (const struct timespec *__time_point,
                                    struct timespec *__remaining),
                       __thrd_sleep64);
# else
#  define thrd_sleep __thrd_sleep64
# endif
#endif

/* Terminate current thread execution, cleaning up any thread local
   storage and freeing resources.  Returns the value specified in __RES.  */
extern void thrd_exit (int __res) __attribute__ ((__noreturn__));

/* Detach the thread identified by __THR from the current environment
   (it does not allow join or wait for it).  */
extern int thrd_detach (thrd_t __thr);

/* Block current thread until execution of __THR is complete.  In case that
   __RES is not NULL, will store the return value of __THR when exiting.  */
extern int thrd_join (thrd_t __thr, int *__res);

/* Stop current thread execution and call the scheduler to decide which
   thread should execute next.  The current thread may be selected by the
   scheduler to keep running.  */
extern void thrd_yield (void);

#ifdef __USE_EXTERN_INLINES
/* Optimizations.  */
__extern_inline int
thrd_equal (thrd_t __thread1, thrd_t __thread2)
{
  return __thread1 == __thread2;
}
#endif


/* Mutex functions.  */

/* Creates a new mutex object with type __TYPE.  If successful the new
   object is pointed by __MUTEX.  */
extern int mtx_init (mtx_t *__mutex, int __type);

/* Block the current thread until the mutex pointed to by __MUTEX is
   unlocked.  In that case current thread will not be blocked.  */
extern int mtx_lock (mtx_t *__mutex);

/* Block the current thread until the mutex pointed by __MUTEX is unlocked
   or time pointed by __TIME_POINT is reached.  In case the mutex is unlock,
   the current thread will not be blocked.  */
#ifndef __USE_TIME_BITS64
extern int mtx_timedlock (mtx_t *__restrict __mutex,
			  const struct timespec *__restrict __time_point);
#else
# ifdef __REDIRECT
extern int __REDIRECT (mtx_timedlock, (mtx_t *__restrict __mutex,
                                       const struct timespec *__restrict
                                       __time_point),
                       __mtx_timedlock64);
# else
#  define mtx_timedlock __mtx_timedlock64
# endif
#endif

/* Try to lock the mutex pointed by __MUTEX without blocking.  If the mutex
   is free the current threads takes control of it, otherwise it returns
   immediately.  */
extern int mtx_trylock (mtx_t *__mutex);

/* Unlock the mutex pointed by __MUTEX.  It may potentially awake other
   threads waiting on this mutex.  */
extern int mtx_unlock (mtx_t *__mutex);

/* Destroy the mutex object pointed by __MUTEX.  */
extern void mtx_destroy (mtx_t *__mutex);


/* Call function __FUNC exactly once, even if invoked from several threads.
   All calls must be made with the same __FLAGS object.  */
extern void call_once (once_flag *__flag, void (*__func)(void));


/* Condition variable functions.  */

/* Initialize new condition variable pointed by __COND.  */
extern int cnd_init (cnd_t *__cond);

/* Unblock one thread that currently waits on condition variable pointed
   by __COND.  */
extern int cnd_signal (cnd_t *__cond);

/* Unblock all threads currently waiting on condition variable pointed by
   __COND.  */
extern int cnd_broadcast (cnd_t *__cond);

/* Block current thread on the condition variable pointed by __COND.  */
extern int cnd_wait (cnd_t *__cond, mtx_t *__mutex);

/* Block current thread on the condition variable until condition variable
   pointed by __COND is signaled or time pointed by __TIME_POINT is
   reached.  */
#ifndef __USE_TIME_BITS64
extern int cnd_timedwait (cnd_t *__restrict __cond,
			  mtx_t *__restrict __mutex,
			  const struct timespec *__restrict __time_point);
#else
# ifdef __REDIRECT
extern int __REDIRECT (cnd_timedwait, (cnd_t *__restrict __cond,
                                       mtx_t *__restrict __mutex,
                                       const struct timespec *__restrict
                                       __time_point),
                       __cnd_timedwait64);
# else
#  define cnd_timedwait __cnd_timedwait64
# endif
#endif

/* Destroy condition variable pointed by __cond and free all of its
   resources.  */
extern void cnd_destroy (cnd_t *__COND);


/* Thread specific storage functions.  */

/* Create new thread-specific storage key and stores it in the object pointed
   by __TSS_ID.  If __DESTRUCTOR is not NULL, the function will be called when
   the thread terminates.  */
extern int tss_create (tss_t *__tss_id, tss_dtor_t __destructor);

/* Return the value held in thread-specific storage for the current thread
   identified by __TSS_ID.  */
extern void *tss_get (tss_t __tss_id);

/* Sets the value of the thread-specific storage identified by __TSS_ID for
   the current thread to __VAL.  */
extern int tss_set (tss_t __tss_id, void *__val);

/* Destroys the thread-specific storage identified by __TSS_ID.  The
   destructor is not called until thrd_exit is called.  */
extern void tss_delete (tss_t __tss_id);

__END_DECLS

#endif /* _THREADS_H */