1 | /* ISO C11 Standard: 7.26 - Thread support library <threads.h>. |
2 | Copyright (C) 2018-2020 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 */ |
208 | |