3c20a679b6
This patch adds the call_* definitions from C11 threads (ISO/IEC 9899:2011),
more specifically call_once and required types.
Mostly of the definitions are composed based on POSIX conterparts,including
once_flag (pthread_once_t). The idea is to make possible to share POSIX
internal implementations for mostly of the code (and making adjustment only
when required).
Checked with a build for all major ABI (aarch64-linux-gnu, alpha-linux-gnu,
arm-linux-gnueabi, i386-linux-gnu, ia64-linux-gnu, m68k-linux-gnu,
microblaze-linux-gnu [1], mips{64}-linux-gnu, nios2-linux-gnu,
powerpc{64le}-linux-gnu, s390{x}-linux-gnu, sparc{64}-linux-gnu,
and x86_64-linux-gnu).
Also ran a full check on aarch64-linux-gnu, x86_64-linux-gnu, i686-linux-gnu,
arm-linux-gnueabhf, and powerpc64le-linux-gnu.
[BZ #14092]
* conform/data/threads.h-data (ONCE_FLAG_INIT): New macro.
(once_flag): New type.
(call_once): New function.
* nptl/Makefile (libpthread-routines): Add call_once object.
* nptl/Versions (libphread) [GLIBC_2.28]: Add call_once symbol.
* nptl/call_once.c: New file.
* sysdeps/nptl/threads.h (ONCE_FLAG_INIT): New define.
(once_flag): New type.
(call_once): New prototype.
146 lines
4.5 KiB
C
146 lines
4.5 KiB
C
/* ISO C11 Standard: 7.26 - Thread support library <threads.h>.
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Copyright (C) 2018 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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<http://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/pthreadtypes-arch.h>
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#include <bits/types/struct_timespec.h>
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typedef unsigned long int 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 struct
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{
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int __data __ONCE_ALIGNMENT;
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} once_flag;
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#define ONCE_FLAG_INIT { 0 }
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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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/* 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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extern int thrd_sleep (const struct timespec *__time_point,
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struct timespec *__remaining);
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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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extern int mtx_timedlock (mtx_t *__restrict __mutex,
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const struct timespec *__restrict __time_point);
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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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__END_DECLS
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#endif /* _THREADS_H */
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