1 /* ISO C11 Standard: 7.26 - Thread support library <threads.h>.
2 Copyright (C) 2018-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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.
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.
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/>. */
27 #include <bits/thread-shared-types.h>
28 #include <bits/types/struct_timespec.h>
30 #if (!defined __STDC_VERSION__ \
31 || __STDC_VERSION__ <= 201710L \
32 || !__GNUC_PREREQ (13, 0)) && !defined __cplusplus
33 # define thread_local _Thread_local
36 #define TSS_DTOR_ITERATIONS 4
37 typedef __tss_t tss_t
;
38 typedef void (*tss_dtor_t
) (void*);
40 typedef __thrd_t thrd_t
;
41 typedef int (*thrd_start_t
) (void*);
43 /* Exit and error codes. */
61 typedef __once_flag once_flag
;
62 #define ONCE_FLAG_INIT __ONCE_FLAG_INIT
66 char __size
[__SIZEOF_PTHREAD_MUTEX_T
];
67 long int __align __LOCK_ALIGNMENT
;
72 char __size
[__SIZEOF_PTHREAD_COND_T
];
73 __extension__
long long int __align __LOCK_ALIGNMENT
;
76 /* Threads functions. */
78 /* Create a new thread executing the function __FUNC. Arguments for __FUNC
79 are passed through __ARG. If successful, __THR is set to new thread
81 extern int thrd_create (thrd_t
*__thr
, thrd_start_t __func
, void *__arg
);
83 /* Check if __LHS and __RHS point to the same thread. */
84 extern int thrd_equal (thrd_t __lhs
, thrd_t __rhs
);
86 /* Return current thread identifier. */
87 extern thrd_t
thrd_current (void);
89 /* Block current thread execution for at least the time pointed by
90 __TIME_POINT. The current thread may resume if receives a signal. In
91 that case, if __REMAINING is not NULL, the remaining time is stored in
92 the object pointed by it. */
93 #ifndef __USE_TIME_BITS64
94 extern int thrd_sleep (const struct timespec
*__time_point
,
95 struct timespec
*__remaining
);
98 extern int __REDIRECT (thrd_sleep
, (const struct timespec
*__time_point
,
99 struct timespec
*__remaining
),
102 # define thrd_sleep __thrd_sleep64
106 /* Terminate current thread execution, cleaning up any thread local
107 storage and freeing resources. Returns the value specified in __RES. */
108 extern void thrd_exit (int __res
) __attribute__ ((__noreturn__
));
110 /* Detach the thread identified by __THR from the current environment
111 (it does not allow join or wait for it). */
112 extern int thrd_detach (thrd_t __thr
);
114 /* Block current thread until execution of __THR is complete. In case that
115 __RES is not NULL, will store the return value of __THR when exiting. */
116 extern int thrd_join (thrd_t __thr
, int *__res
);
118 /* Stop current thread execution and call the scheduler to decide which
119 thread should execute next. The current thread may be selected by the
120 scheduler to keep running. */
121 extern void thrd_yield (void);
123 #ifdef __USE_EXTERN_INLINES
126 thrd_equal (thrd_t __thread1
, thrd_t __thread2
)
128 return __thread1
== __thread2
;
133 /* Mutex functions. */
135 /* Creates a new mutex object with type __TYPE. If successful the new
136 object is pointed by __MUTEX. */
137 extern int mtx_init (mtx_t
*__mutex
, int __type
);
139 /* Block the current thread until the mutex pointed to by __MUTEX is
140 unlocked. In that case current thread will not be blocked. */
141 extern int mtx_lock (mtx_t
*__mutex
);
143 /* Block the current thread until the mutex pointed by __MUTEX is unlocked
144 or time pointed by __TIME_POINT is reached. In case the mutex is unlock,
145 the current thread will not be blocked. */
146 #ifndef __USE_TIME_BITS64
147 extern int mtx_timedlock (mtx_t
*__restrict __mutex
,
148 const struct timespec
*__restrict __time_point
);
151 extern int __REDIRECT (mtx_timedlock
, (mtx_t
*__restrict __mutex
,
152 const struct timespec
*__restrict
156 # define mtx_timedlock __mtx_timedlock64
160 /* Try to lock the mutex pointed by __MUTEX without blocking. If the mutex
161 is free the current threads takes control of it, otherwise it returns
163 extern int mtx_trylock (mtx_t
*__mutex
);
165 /* Unlock the mutex pointed by __MUTEX. It may potentially awake other
166 threads waiting on this mutex. */
167 extern int mtx_unlock (mtx_t
*__mutex
);
169 /* Destroy the mutex object pointed by __MUTEX. */
170 extern void mtx_destroy (mtx_t
*__mutex
);
173 /* Call function __FUNC exactly once, even if invoked from several threads.
174 All calls must be made with the same __FLAGS object. */
175 extern void call_once (once_flag
*__flag
, void (*__func
)(void));
178 /* Condition variable functions. */
180 /* Initialize new condition variable pointed by __COND. */
181 extern int cnd_init (cnd_t
*__cond
);
183 /* Unblock one thread that currently waits on condition variable pointed
185 extern int cnd_signal (cnd_t
*__cond
);
187 /* Unblock all threads currently waiting on condition variable pointed by
189 extern int cnd_broadcast (cnd_t
*__cond
);
191 /* Block current thread on the condition variable pointed by __COND. */
192 extern int cnd_wait (cnd_t
*__cond
, mtx_t
*__mutex
);
194 /* Block current thread on the condition variable until condition variable
195 pointed by __COND is signaled or time pointed by __TIME_POINT is
197 #ifndef __USE_TIME_BITS64
198 extern int cnd_timedwait (cnd_t
*__restrict __cond
,
199 mtx_t
*__restrict __mutex
,
200 const struct timespec
*__restrict __time_point
);
203 extern int __REDIRECT (cnd_timedwait
, (cnd_t
*__restrict __cond
,
204 mtx_t
*__restrict __mutex
,
205 const struct timespec
*__restrict
209 # define cnd_timedwait __cnd_timedwait64
213 /* Destroy condition variable pointed by __cond and free all of its
215 extern void cnd_destroy (cnd_t
*__COND
);
218 /* Thread specific storage functions. */
220 /* Create new thread-specific storage key and stores it in the object pointed
221 by __TSS_ID. If __DESTRUCTOR is not NULL, the function will be called when
222 the thread terminates. */
223 extern int tss_create (tss_t
*__tss_id
, tss_dtor_t __destructor
);
225 /* Return the value held in thread-specific storage for the current thread
226 identified by __TSS_ID. */
227 extern void *tss_get (tss_t __tss_id
);
229 /* Sets the value of the thread-specific storage identified by __TSS_ID for
230 the current thread to __VAL. */
231 extern int tss_set (tss_t __tss_id
, void *__val
);
233 /* Destroys the thread-specific storage identified by __TSS_ID. The
234 destructor is not called until thrd_exit is called. */
235 extern void tss_delete (tss_t __tss_id
);
239 #endif /* _THREADS_H */