[userspace-rcu.git] / urcu / urcu-futex.h

#ifndef _URCU_FUTEX_H
#define _URCU_FUTEX_H

/*
 * urcu-futex.h
 *
 * Userspace RCU - sys_futex/compat_futex header.
 *
 * This 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.
 *
 * This 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 this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <urcu/config.h>

#ifdef __cplusplus
extern "C" {
#endif 

#define FUTEX_WAIT		0
#define FUTEX_WAKE		1

/*
 * sys_futex compatibility header.
 * Use *only* *either of* futex_noasync OR futex_async on a given address.
 *
 * futex_noasync cannot be executed in signal handlers, but ensures that
 * it will be put in a wait queue even in compatibility mode.
 *
 * futex_async is signal-handler safe for the wakeup. It uses polling
 * on the wait-side in compatibility mode.
 */

#ifdef CONFIG_RCU_HAVE_FUTEX
#include <sys/syscall.h>
#define futex(...)	syscall(__NR_futex, __VA_ARGS__)
#define futex_noasync(uaddr, op, val, timeout, uaddr2, val3)	\
		futex(uaddr, op, val, timeout, uaddr2, val3)
#define futex_async(uaddr, op, val, timeout, uaddr2, val3)	\
		futex(uaddr, op, val, timeout, uaddr2, val3)
#else
extern int compat_futex_noasync(int *uaddr, int op, int val,
	const struct timespec *timeout, int *uaddr2, int val3);
#define futex_noasync(uaddr, op, val, timeout, uaddr2, val3)	\
		compat_futex_noasync(uaddr, op, val, timeout, uaddr2, val3)
extern int compat_futex_async(int *uaddr, int op, int val,
	const struct timespec *timeout, int *uaddr2, int val3);
#define futex_async(uaddr, op, val, timeout, uaddr2, val3)	\
		compat_futex_async(uaddr, op, val, timeout, uaddr2, val3)
#endif

#ifdef __cplusplus 
}
#endif

#endif /* _URCU_FUTEX_H */
Commit	Line	Data
	1	#ifndef _URCU_FUTEX_H
	2	#define _URCU_FUTEX_H
	3
	4	/*
	5	* urcu-futex.h
	6	*
	7	* Userspace RCU - sys_futex/compat_futex header.
	8	*
	9	* This library is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU Lesser General Public
	11	* License as published by the Free Software Foundation; either
	12	* version 2.1 of the License, or (at your option) any later version.
	13	*
	14	* This library is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	17	* Lesser General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU Lesser General Public
	20	* License along with this library; if not, write to the Free Software
	21	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	22	*/
	23
	24	#include <urcu/config.h>
	25
	26	#ifdef __cplusplus
	27	extern "C" {
	28	#endif
	29
	30	#define FUTEX_WAIT 0
	31	#define FUTEX_WAKE 1
	32
	33	/*
	34	* sys_futex compatibility header.
	35	* Use only either of futex_noasync OR futex_async on a given address.
	36	*
	37	* futex_noasync cannot be executed in signal handlers, but ensures that
	38	* it will be put in a wait queue even in compatibility mode.
	39	*
	40	* futex_async is signal-handler safe for the wakeup. It uses polling
	41	* on the wait-side in compatibility mode.
	42	*/
	43
	44	#ifdef CONFIG_RCU_HAVE_FUTEX
	45	#include <sys/syscall.h>
	46	#define futex(...) syscall(__NR_futex, __VA_ARGS__)
	47	#define futex_noasync(uaddr, op, val, timeout, uaddr2, val3) \
	48	futex(uaddr, op, val, timeout, uaddr2, val3)
	49	#define futex_async(uaddr, op, val, timeout, uaddr2, val3) \
	50	futex(uaddr, op, val, timeout, uaddr2, val3)
	51	#else
	52	extern int compat_futex_noasync(int *uaddr, int op, int val,
	53	const struct timespec timeout, int uaddr2, int val3);
	54	#define futex_noasync(uaddr, op, val, timeout, uaddr2, val3) \
	55	compat_futex_noasync(uaddr, op, val, timeout, uaddr2, val3)
	56	extern int compat_futex_async(int *uaddr, int op, int val,
	57	const struct timespec timeout, int uaddr2, int val3);
	58	#define futex_async(uaddr, op, val, timeout, uaddr2, val3) \
	59	compat_futex_async(uaddr, op, val, timeout, uaddr2, val3)
	60	#endif
	61
	62	#ifdef __cplusplus
	63	}
	64	#endif
	65
	66	#endif /* _URCU_FUTEX_H */