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1 | /* ISO C11 Standard: 7.26 - Thread support library <threads.h>. | |
2 | Copyright (C) 2018-2019 Free Software Foundation, Inc. | |
3 | This file is part of the GNU C Library. | |
4 | ||
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. | |
9 | ||
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. | |
14 | ||
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/>. */ | |
18 | ||
19 | #ifndef _THREADS_H | |
20 | #define _THREADS_H 1 | |
21 | ||
22 | #include <features.h> | |
23 | #include <time.h> | |
24 | ||
25 | __BEGIN_DECLS | |
26 | ||
27 | #include <bits/pthreadtypes-arch.h> | |
28 | #include <bits/types/struct_timespec.h> | |
29 | ||
30 | #ifndef __cplusplus | |
31 | # define thread_local _Thread_local | |
32 | #endif | |
33 | ||
34 | #define TSS_DTOR_ITERATIONS 4 | |
35 | typedef unsigned int tss_t; | |
36 | typedef void (*tss_dtor_t) (void*); | |
37 | ||
38 | typedef unsigned long int thrd_t; | |
39 | typedef int (*thrd_start_t) (void*); | |
40 | ||
41 | /* Exit and error codes. */ | |
42 | enum | |
43 | { | |
44 | thrd_success = 0, | |
45 | thrd_busy = 1, | |
46 | thrd_error = 2, | |
47 | thrd_nomem = 3, | |
48 | thrd_timedout = 4 | |
49 | }; | |
50 | ||
51 | /* Mutex types. */ | |
52 | enum | |
53 | { | |
54 | mtx_plain = 0, | |
55 | mtx_recursive = 1, | |
56 | mtx_timed = 2 | |
57 | }; | |
58 | ||
59 | typedef struct | |
60 | { | |
61 | int __data __ONCE_ALIGNMENT; | |
62 | } once_flag; | |
63 | #define ONCE_FLAG_INIT { 0 } | |
64 | ||
65 | typedef union | |
66 | { | |
67 | char __size[__SIZEOF_PTHREAD_MUTEX_T]; | |
68 | long int __align __LOCK_ALIGNMENT; | |
69 | } mtx_t; | |
70 | ||
71 | typedef union | |
72 | { | |
73 | char __size[__SIZEOF_PTHREAD_COND_T]; | |
74 | __extension__ long long int __align __LOCK_ALIGNMENT; | |
75 | } cnd_t; | |
76 | ||
77 | /* Threads functions. */ | |
78 | ||
79 | /* Create a new thread executing the function __FUNC. Arguments for __FUNC | |
80 | are passed through __ARG. If succesful, __THR is set to new thread | |
81 | identifier. */ | |
82 | extern int thrd_create (thrd_t *__thr, thrd_start_t __func, void *__arg); | |
83 | ||
84 | /* Check if __LHS and __RHS point to the same thread. */ | |
85 | extern int thrd_equal (thrd_t __lhs, thrd_t __rhs); | |
86 | ||
87 | /* Return current thread identifier. */ | |
88 | extern thrd_t thrd_current (void); | |
89 | ||
90 | /* Block current thread execution for at least the time pointed by | |
91 | __TIME_POINT. The current thread may resume if receives a signal. In | |
92 | that case, if __REMAINING is not NULL, the remaining time is stored in | |
93 | the object pointed by it. */ | |
94 | extern int thrd_sleep (const struct timespec *__time_point, | |
95 | struct timespec *__remaining); | |
96 | ||
97 | /* Terminate current thread execution, cleaning up any thread local | |
98 | storage and freeing resources. Returns the value specified in __RES. */ | |
99 | extern void thrd_exit (int __res) __attribute__ ((__noreturn__)); | |
100 | ||
101 | /* Detach the thread identified by __THR from the current environment | |
102 | (it does not allow join or wait for it). */ | |
103 | extern int thrd_detach (thrd_t __thr); | |
104 | ||
105 | /* Block current thread until execution of __THR is complete. In case that | |
106 | __RES is not NULL, will store the return value of __THR when exiting. */ | |
107 | extern int thrd_join (thrd_t __thr, int *__res); | |
108 | ||
109 | /* Stop current thread execution and call the scheduler to decide which | |
110 | thread should execute next. The current thread may be selected by the | |
111 | scheduler to keep running. */ | |
112 | extern void thrd_yield (void); | |
113 | ||
114 | #ifdef __USE_EXTERN_INLINES | |
115 | /* Optimizations. */ | |
116 | __extern_inline int | |
117 | thrd_equal (thrd_t __thread1, thrd_t __thread2) | |
118 | { | |
119 | return __thread1 == __thread2; | |
120 | } | |
121 | #endif | |
122 | ||
123 | ||
124 | /* Mutex functions. */ | |
125 | ||
126 | /* Creates a new mutex object with type __TYPE. If successful the new | |
127 | object is pointed by __MUTEX. */ | |
128 | extern int mtx_init (mtx_t *__mutex, int __type); | |
129 | ||
130 | /* Block the current thread until the mutex pointed to by __MUTEX is | |
131 | unlocked. In that case current thread will not be blocked. */ | |
132 | extern int mtx_lock (mtx_t *__mutex); | |
133 | ||
134 | /* Block the current thread until the mutex pointed by __MUTEX is unlocked | |
135 | or time pointed by __TIME_POINT is reached. In case the mutex is unlock, | |
136 | the current thread will not be blocked. */ | |
137 | extern int mtx_timedlock (mtx_t *__restrict __mutex, | |
138 | const struct timespec *__restrict __time_point); | |
139 | ||
140 | /* Try to lock the mutex pointed by __MUTEX without blocking. If the mutex | |
141 | is free the current threads takes control of it, otherwise it returns | |
142 | immediately. */ | |
143 | extern int mtx_trylock (mtx_t *__mutex); | |
144 | ||
145 | /* Unlock the mutex pointed by __MUTEX. It may potentially awake other | |
146 | threads waiting on this mutex. */ | |
147 | extern int mtx_unlock (mtx_t *__mutex); | |
148 | ||
149 | /* Destroy the mutex object pointed by __MUTEX. */ | |
150 | extern void mtx_destroy (mtx_t *__mutex); | |
151 | ||
152 | ||
153 | /* Call function __FUNC exactly once, even if invoked from several threads. | |
154 | All calls must be made with the same __FLAGS object. */ | |
155 | extern void call_once (once_flag *__flag, void (*__func)(void)); | |
156 | ||
157 | ||
158 | /* Condition variable functions. */ | |
159 | ||
160 | /* Initialize new condition variable pointed by __COND. */ | |
161 | extern int cnd_init (cnd_t *__cond); | |
162 | ||
163 | /* Unblock one thread that currently waits on condition variable pointed | |
164 | by __COND. */ | |
165 | extern int cnd_signal (cnd_t *__cond); | |
166 | ||
167 | /* Unblock all threads currently waiting on condition variable pointed by | |
168 | __COND. */ | |
169 | extern int cnd_broadcast (cnd_t *__cond); | |
170 | ||
171 | /* Block current thread on the condition variable pointed by __COND. */ | |
172 | extern int cnd_wait (cnd_t *__cond, mtx_t *__mutex); | |
173 | ||
174 | /* Block current thread on the condition variable until condition variable | |
175 | pointed by __COND is signaled or time pointed by __TIME_POINT is | |
176 | reached. */ | |
177 | extern int cnd_timedwait (cnd_t *__restrict __cond, | |
178 | mtx_t *__restrict __mutex, | |
179 | const struct timespec *__restrict __time_point); | |
180 | ||
181 | /* Destroy condition variable pointed by __cond and free all of its | |
182 | resources. */ | |
183 | extern void cnd_destroy (cnd_t *__COND); | |
184 | ||
185 | ||
186 | /* Thread specific storage functions. */ | |
187 | ||
188 | /* Create new thread-specific storage key and stores it in the object pointed | |
189 | by __TSS_ID. If __DESTRUCTOR is not NULL, the function will be called when | |
190 | the thread terminates. */ | |
191 | extern int tss_create (tss_t *__tss_id, tss_dtor_t __destructor); | |
192 | ||
193 | /* Return the value held in thread-specific storage for the current thread | |
194 | identified by __TSS_ID. */ | |
195 | extern void *tss_get (tss_t __tss_id); | |
196 | ||
197 | /* Sets the value of the thread-specific storage identified by __TSS_ID for | |
198 | the current thread to __VAL. */ | |
199 | extern int tss_set (tss_t __tss_id, void *__val); | |
200 | ||
201 | /* Destroys the thread-specific storage identified by __TSS_ID. The | |
202 | destructor is not called until thrd_exit is called. */ | |
203 | extern void tss_delete (tss_t __tss_id); | |
204 | ||
205 | __END_DECLS | |
206 | ||
207 | #endif /* _THREADS_H */ |