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The C and C++ Include Header Files

/usr/include/threads.h


$ cat -n /usr/include/threads.h

     1	/* ISO C11 Standard: 7.26 - Thread support library  <threads.h>.
     2	   Copyright (C) 2018-2024 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/thread-shared-types.h>
    28	#include <bits/types/struct_timespec.h>
    29	
    30	#if (!defined __STDC_VERSION__				\
    31	     || __STDC_VERSION__ <= 201710L			\
    32	     || !__GNUC_PREREQ (13, 0)) && !defined __cplusplus
    33	# define thread_local _Thread_local
    34	#endif
    35	
    36	#define TSS_DTOR_ITERATIONS 4
    37	typedef __tss_t tss_t;
    38	typedef void (*tss_dtor_t) (void*);
    39	
    40	typedef __thrd_t thrd_t;
    41	typedef int (*thrd_start_t) (void*);
    42	
    43	/* Exit and error codes.  */
    44	enum
    45	{
    46	  thrd_success  = 0,
    47	  thrd_busy     = 1,
    48	  thrd_error    = 2,
    49	  thrd_nomem    = 3,
    50	  thrd_timedout = 4
    51	};
    52	
    53	/* Mutex types.  */
    54	enum
    55	{
    56	  mtx_plain     = 0,
    57	  mtx_recursive = 1,
    58	  mtx_timed     = 2
    59	};
    60	
    61	typedef __once_flag once_flag;
    62	#define ONCE_FLAG_INIT __ONCE_FLAG_INIT
    63	
    64	typedef union
    65	{
    66	  char __size[__SIZEOF_PTHREAD_MUTEX_T];
    67	  long int __align __LOCK_ALIGNMENT;
    68	} mtx_t;
    69	
    70	typedef union
    71	{
    72	  char __size[__SIZEOF_PTHREAD_COND_T];
    73	  __extension__ long long int __align __LOCK_ALIGNMENT;
    74	} cnd_t;
    75	
    76	/* Threads functions.  */
    77	
    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
    80	   identifier.  */
    81	extern int thrd_create (thrd_t *__thr, thrd_start_t __func, void *__arg);
    82	
    83	/* Check if __LHS and __RHS point to the same thread.  */
    84	extern int thrd_equal (thrd_t __lhs, thrd_t __rhs);
    85	
    86	/* Return current thread identifier.  */
    87	extern thrd_t thrd_current (void);
    88	
    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);
    96	#else
    97	# ifdef __REDIRECT
    98	extern int __REDIRECT (thrd_sleep, (const struct timespec *__time_point,
    99	                                    struct timespec *__remaining),
   100	                       __thrd_sleep64);
   101	# else
   102	#  define thrd_sleep __thrd_sleep64
   103	# endif
   104	#endif
   105	
   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__));
   109	
   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);
   113	
   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);
   117	
   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);
   122	
   123	#ifdef __USE_EXTERN_INLINES
   124	/* Optimizations.  */
   125	__extern_inline int
   126	thrd_equal (thrd_t __thread1, thrd_t __thread2)
   127	{
   128	  return __thread1 == __thread2;
   129	}
   130	#endif
   131	
   132	
   133	/* Mutex functions.  */
   134	
   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);
   138	
   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);
   142	
   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);
   149	#else
   150	# ifdef __REDIRECT
   151	extern int __REDIRECT (mtx_timedlock, (mtx_t *__restrict __mutex,
   152	                                       const struct timespec *__restrict
   153	                                       __time_point),
   154	                       __mtx_timedlock64);
   155	# else
   156	#  define mtx_timedlock __mtx_timedlock64
   157	# endif
   158	#endif
   159	
   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
   162	   immediately.  */
   163	extern int mtx_trylock (mtx_t *__mutex);
   164	
   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);
   168	
   169	/* Destroy the mutex object pointed by __MUTEX.  */
   170	extern void mtx_destroy (mtx_t *__mutex);
   171	
   172	
   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));
   176	
   177	
   178	/* Condition variable functions.  */
   179	
   180	/* Initialize new condition variable pointed by __COND.  */
   181	extern int cnd_init (cnd_t *__cond);
   182	
   183	/* Unblock one thread that currently waits on condition variable pointed
   184	   by __COND.  */
   185	extern int cnd_signal (cnd_t *__cond);
   186	
   187	/* Unblock all threads currently waiting on condition variable pointed by
   188	   __COND.  */
   189	extern int cnd_broadcast (cnd_t *__cond);
   190	
   191	/* Block current thread on the condition variable pointed by __COND.  */
   192	extern int cnd_wait (cnd_t *__cond, mtx_t *__mutex);
   193	
   194	/* Block current thread on the condition variable until condition variable
   195	   pointed by __COND is signaled or time pointed by __TIME_POINT is
   196	   reached.  */
   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);
   201	#else
   202	# ifdef __REDIRECT
   203	extern int __REDIRECT (cnd_timedwait, (cnd_t *__restrict __cond,
   204	                                       mtx_t *__restrict __mutex,
   205	                                       const struct timespec *__restrict
   206	                                       __time_point),
   207	                       __cnd_timedwait64);
   208	# else
   209	#  define cnd_timedwait __cnd_timedwait64
   210	# endif
   211	#endif
   212	
   213	/* Destroy condition variable pointed by __cond and free all of its
   214	   resources.  */
   215	extern void cnd_destroy (cnd_t *__COND);
   216	
   217	
   218	/* Thread specific storage functions.  */
   219	
   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);
   224	
   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);
   228	
   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);
   232	
   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);
   236	
   237	__END_DECLS
   238	
   239	#endif /* _THREADS_H */