glibc/nptl/threads.h

146 lines
4.5 KiB
C

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