238 lines
7.5 KiB
C
238 lines
7.5 KiB
C
/* ISO C11 Standard: 7.26 - Thread support library <threads.h>.
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Copyright (C) 2018-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#ifndef _THREADS_H
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#define _THREADS_H 1
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#include <features.h>
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#include <time.h>
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__BEGIN_DECLS
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#include <bits/thread-shared-types.h>
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#include <bits/types/struct_timespec.h>
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#ifndef __cplusplus
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# define thread_local _Thread_local
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#endif
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#define TSS_DTOR_ITERATIONS 4
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typedef __tss_t tss_t;
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typedef void (*tss_dtor_t) (void*);
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typedef __thrd_t thrd_t;
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typedef int (*thrd_start_t) (void*);
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/* Exit and error codes. */
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enum
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{
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thrd_success = 0,
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thrd_busy = 1,
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thrd_error = 2,
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thrd_nomem = 3,
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thrd_timedout = 4
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};
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/* Mutex types. */
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enum
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{
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mtx_plain = 0,
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mtx_recursive = 1,
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mtx_timed = 2
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};
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typedef __once_flag once_flag;
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#define ONCE_FLAG_INIT __ONCE_FLAG_INIT
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typedef union
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{
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char __size[__SIZEOF_PTHREAD_MUTEX_T];
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long int __align __LOCK_ALIGNMENT;
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} mtx_t;
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typedef union
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{
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char __size[__SIZEOF_PTHREAD_COND_T];
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__extension__ long long int __align __LOCK_ALIGNMENT;
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} cnd_t;
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/* Threads functions. */
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/* Create a new thread executing the function __FUNC. Arguments for __FUNC
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are passed through __ARG. If succesful, __THR is set to new thread
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identifier. */
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extern int thrd_create (thrd_t *__thr, thrd_start_t __func, void *__arg);
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/* Check if __LHS and __RHS point to the same thread. */
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extern int thrd_equal (thrd_t __lhs, thrd_t __rhs);
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/* Return current thread identifier. */
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extern thrd_t thrd_current (void);
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/* Block current thread execution for at least the time pointed by
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__TIME_POINT. The current thread may resume if receives a signal. In
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that case, if __REMAINING is not NULL, the remaining time is stored in
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the object pointed by it. */
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#ifndef __USE_TIME_BITS64
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extern int thrd_sleep (const struct timespec *__time_point,
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struct timespec *__remaining);
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#else
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# ifdef __REDIRECT
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extern int __REDIRECT (thrd_sleep, (const struct timespec *__time_point,
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struct timespec *__remaining),
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__thrd_sleep64);
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# else
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# define thrd_sleep __thrd_sleep64
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# endif
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#endif
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/* Terminate current thread execution, cleaning up any thread local
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storage and freeing resources. Returns the value specified in __RES. */
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extern void thrd_exit (int __res) __attribute__ ((__noreturn__));
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/* Detach the thread identified by __THR from the current environment
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(it does not allow join or wait for it). */
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extern int thrd_detach (thrd_t __thr);
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/* Block current thread until execution of __THR is complete. In case that
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__RES is not NULL, will store the return value of __THR when exiting. */
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extern int thrd_join (thrd_t __thr, int *__res);
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/* Stop current thread execution and call the scheduler to decide which
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thread should execute next. The current thread may be selected by the
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scheduler to keep running. */
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extern void thrd_yield (void);
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#ifdef __USE_EXTERN_INLINES
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/* Optimizations. */
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__extern_inline int
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thrd_equal (thrd_t __thread1, thrd_t __thread2)
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{
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return __thread1 == __thread2;
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}
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#endif
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/* Mutex functions. */
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/* Creates a new mutex object with type __TYPE. If successful the new
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object is pointed by __MUTEX. */
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extern int mtx_init (mtx_t *__mutex, int __type);
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/* Block the current thread until the mutex pointed to by __MUTEX is
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unlocked. In that case current thread will not be blocked. */
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extern int mtx_lock (mtx_t *__mutex);
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/* Block the current thread until the mutex pointed by __MUTEX is unlocked
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or time pointed by __TIME_POINT is reached. In case the mutex is unlock,
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the current thread will not be blocked. */
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#ifndef __USE_TIME_BITS64
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extern int mtx_timedlock (mtx_t *__restrict __mutex,
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const struct timespec *__restrict __time_point);
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#else
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# ifdef __REDIRECT
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extern int __REDIRECT (mtx_timedlock, (mtx_t *__restrict __mutex,
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const struct timespec *__restrict
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__time_point),
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__mtx_timedlock64);
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# else
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# define mtx_timedlock __mtx_timedlock64
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# endif
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#endif
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/* Try to lock the mutex pointed by __MUTEX without blocking. If the mutex
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is free the current threads takes control of it, otherwise it returns
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immediately. */
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extern int mtx_trylock (mtx_t *__mutex);
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/* Unlock the mutex pointed by __MUTEX. It may potentially awake other
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threads waiting on this mutex. */
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extern int mtx_unlock (mtx_t *__mutex);
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/* Destroy the mutex object pointed by __MUTEX. */
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extern void mtx_destroy (mtx_t *__mutex);
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/* Call function __FUNC exactly once, even if invoked from several threads.
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All calls must be made with the same __FLAGS object. */
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extern void call_once (once_flag *__flag, void (*__func)(void));
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/* Condition variable functions. */
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/* Initialize new condition variable pointed by __COND. */
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extern int cnd_init (cnd_t *__cond);
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/* Unblock one thread that currently waits on condition variable pointed
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by __COND. */
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extern int cnd_signal (cnd_t *__cond);
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/* Unblock all threads currently waiting on condition variable pointed by
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__COND. */
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extern int cnd_broadcast (cnd_t *__cond);
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/* Block current thread on the condition variable pointed by __COND. */
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extern int cnd_wait (cnd_t *__cond, mtx_t *__mutex);
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/* Block current thread on the condition variable until condition variable
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pointed by __COND is signaled or time pointed by __TIME_POINT is
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reached. */
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#ifndef __USE_TIME_BITS64
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extern int cnd_timedwait (cnd_t *__restrict __cond,
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mtx_t *__restrict __mutex,
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const struct timespec *__restrict __time_point);
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#else
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# ifdef __REDIRECT
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extern int __REDIRECT (cnd_timedwait, (cnd_t *__restrict __cond,
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mtx_t *__restrict __mutex,
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const struct timespec *__restrict
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__time_point),
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__cnd_timedwait64);
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# else
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# define cnd_timedwait __cnd_timedwait64
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# endif
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#endif
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/* Destroy condition variable pointed by __cond and free all of its
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resources. */
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extern void cnd_destroy (cnd_t *__COND);
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/* Thread specific storage functions. */
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/* Create new thread-specific storage key and stores it in the object pointed
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by __TSS_ID. If __DESTRUCTOR is not NULL, the function will be called when
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the thread terminates. */
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extern int tss_create (tss_t *__tss_id, tss_dtor_t __destructor);
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/* Return the value held in thread-specific storage for the current thread
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identified by __TSS_ID. */
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extern void *tss_get (tss_t __tss_id);
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/* Sets the value of the thread-specific storage identified by __TSS_ID for
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the current thread to __VAL. */
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extern int tss_set (tss_t __tss_id, void *__val);
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/* Destroys the thread-specific storage identified by __TSS_ID. The
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destructor is not called until thrd_exit is called. */
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extern void tss_delete (tss_t __tss_id);
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__END_DECLS
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#endif /* _THREADS_H */
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