sysdeps/unix/sysv/linux/arm/nptl/lowlevellock.h - chromiumos/third_party/glibc-ports - Git at Google

 /* Copyright (C) 2005, 2006, 2007, 2008, 2009 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, write to the Free
    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307 USA.  */

 #ifndef _LOWLEVELLOCK_H
 #define _LOWLEVELLOCK_H	1

 #include <time.h>
 #include <sys/param.h>
 #include <bits/pthreadtypes.h>
 #include <atomic.h>
 #include <sysdep.h>
 #include <kernel-features.h>

 #define FUTEX_WAIT		0
 #define FUTEX_WAKE		1
 #define FUTEX_REQUEUE		3
 #define FUTEX_CMP_REQUEUE	4
 #define FUTEX_WAKE_OP		5
 #define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE	((4 << 24) | 1)
 #define FUTEX_LOCK_PI		6
 #define FUTEX_UNLOCK_PI		7
 #define FUTEX_TRYLOCK_PI	8
 #define FUTEX_WAIT_BITSET	9
 #define FUTEX_WAKE_BITSET	10
 #define FUTEX_PRIVATE_FLAG	128
 #define FUTEX_CLOCK_REALTIME	256

 #define FUTEX_BITSET_MATCH_ANY	0xffffffff

 /* Values for 'private' parameter of locking macros.  Yes, the
    definition seems to be backwards.  But it is not.  The bit will be
    reversed before passing to the system call.  */
 #define LLL_PRIVATE	0
 #define LLL_SHARED	FUTEX_PRIVATE_FLAG


 #if !defined NOT_IN_libc || defined IS_IN_rtld
 /* In libc.so or ld.so all futexes are private.  */
 # ifdef __ASSUME_PRIVATE_FUTEX
 #  define __lll_private_flag(fl, private) \
   ((fl) | FUTEX_PRIVATE_FLAG)
 # else
 #  define __lll_private_flag(fl, private) \
   ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex))
 # endif
 #else
 # ifdef __ASSUME_PRIVATE_FUTEX
 #  define __lll_private_flag(fl, private) \
   (((fl) | FUTEX_PRIVATE_FLAG) ^ (private))
 # else
 #  define __lll_private_flag(fl, private) \
   (__builtin_constant_p (private)					      \
    ? ((private) == 0							      \
       ? ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex))	      \
       : (fl))								      \
    : ((fl) | (((private) ^ FUTEX_PRIVATE_FLAG)				      \
 	      & THREAD_GETMEM (THREAD_SELF, header.private_futex))))
 # endif
 #endif


 #define lll_futex_wait(futexp, val, private) \
   lll_futex_timed_wait(futexp, val, NULL, private)

 #define lll_futex_timed_wait(futexp, val, timespec, private) \
   ({									      \
     INTERNAL_SYSCALL_DECL (__err);					      \
     long int __ret;							      \
     __ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp),		      \
 			      __lll_private_flag (FUTEX_WAIT, private),	      \
 			      (val), (timespec));			      \
     __ret;								      \
   })

 #define lll_futex_wake(futexp, nr, private) \
   ({									      \
     INTERNAL_SYSCALL_DECL (__err);					      \
     long int __ret;							      \
     __ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp),		      \
 			      __lll_private_flag (FUTEX_WAKE, private),	      \
 			      (nr), 0);					      \
     __ret;								      \
   })

 #define lll_robust_dead(futexv, private) \
   do									      \
     {									      \
       int *__futexp = &(futexv);					      \
       atomic_or (__futexp, FUTEX_OWNER_DIED);				      \
       lll_futex_wake (__futexp, 1, private);				      \
     }									      \
   while (0)

 /* Returns non-zero if error happened, zero if success.  */
 #define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \
   ({									      \
     INTERNAL_SYSCALL_DECL (__err);					      \
     long int __ret;							      \
     __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp),		      \
 			      __lll_private_flag (FUTEX_CMP_REQUEUE, private),\
 			      (nr_wake), (nr_move), (mutex), (val));	      \
     INTERNAL_SYSCALL_ERROR_P (__ret, __err);				      \
   })


 /* Returns non-zero if error happened, zero if success.  */
 #define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \
   ({									      \
     INTERNAL_SYSCALL_DECL (__err);					      \
     long int __ret;							      \
     __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp),		      \
 			      __lll_private_flag (FUTEX_WAKE_OP, private),    \
 			      (nr_wake), (nr_wake2), (futexp2),		      \
 			      FUTEX_OP_CLEAR_WAKE_IF_GT_ONE);		      \
     INTERNAL_SYSCALL_ERROR_P (__ret, __err);				      \
   })


 #define lll_trylock(lock)	\
   atomic_compare_and_exchange_val_acq(&(lock), 1, 0)

 #define lll_cond_trylock(lock)	\
   atomic_compare_and_exchange_val_acq(&(lock), 2, 0)

 #define __lll_robust_trylock(futex, id) \
   (atomic_compare_and_exchange_val_acq (futex, id, 0) != 0)
 #define lll_robust_trylock(lock, id) \
   __lll_robust_trylock (&(lock), id)

 extern void __lll_lock_wait_private (int *futex) attribute_hidden;
 extern void __lll_lock_wait (int *futex, int private) attribute_hidden;
 extern int __lll_robust_lock_wait (int *futex, int private) attribute_hidden;

 #define __lll_lock(futex, private)					      \
   ((void) ({								      \
     int *__futex = (futex);						      \
     if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex,       \
 								1, 0), 0))    \
       {									      \
 	if (__builtin_constant_p (private) && (private) == LLL_PRIVATE)	      \
 	  __lll_lock_wait_private (__futex);				      \
 	else								      \
 	  __lll_lock_wait (__futex, private);				      \
       }									      \
   }))
 #define lll_lock(futex, private) __lll_lock (&(futex), private)


 #define __lll_robust_lock(futex, id, private)				      \
   ({									      \
     int *__futex = (futex);						      \
     int __val = 0;							      \
 									      \
     if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id,  \
 								0), 0))	      \
       __val = __lll_robust_lock_wait (__futex, private);		      \
     __val;								      \
   })
 #define lll_robust_lock(futex, id, private) \
   __lll_robust_lock (&(futex), id, private)


 #define __lll_cond_lock(futex, private)					      \
   ((void) ({								      \
     int *__futex = (futex);						      \
     if (__builtin_expect (atomic_exchange_acq (__futex, 2), 0))		      \
       __lll_lock_wait (__futex, private);				      \
   }))
 #define lll_cond_lock(futex, private) __lll_cond_lock (&(futex), private)


 #define lll_robust_cond_lock(futex, id, private) \
   __lll_robust_lock (&(futex), (id) | FUTEX_WAITERS, private)


 extern int __lll_timedlock_wait (int *futex, const struct timespec *,
 				 int private) attribute_hidden;
 extern int __lll_robust_timedlock_wait (int *futex, const struct timespec *,
 					int private) attribute_hidden;

 #define __lll_timedlock(futex, abstime, private)			      \
   ({									      \
      int *__futex = (futex);						      \
      int __val = 0;							      \
 									      \
      if (__builtin_expect (atomic_exchange_acq (__futex, 1), 0))	      \
        __val = __lll_timedlock_wait (__futex, abstime, private);	      \
      __val;								      \
   })
 #define lll_timedlock(futex, abstime, private) \
   __lll_timedlock (&(futex), abstime, private)


 #define __lll_robust_timedlock(futex, abstime, id, private)		      \
   ({									      \
     int *__futex = (futex);						      \
     int __val = 0;							      \
 									      \
     if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id,  \
 								0), 0))	      \
       __val = __lll_robust_timedlock_wait (__futex, abstime, private);	      \
     __val;								      \
   })
 #define lll_robust_timedlock(futex, abstime, id, private) \
   __lll_robust_timedlock (&(futex), abstime, id, private)


 #define __lll_unlock(futex, private) \
   (void)							\
     ({ int *__futex = (futex);					\
        int __oldval = atomic_exchange_rel (__futex, 0);		\
        if (__builtin_expect (__oldval > 1, 0))			\
 	 lll_futex_wake (__futex, 1, private);			\
     })
 #define lll_unlock(futex, private) __lll_unlock(&(futex), private)


 #define __lll_robust_unlock(futex, private) \
   (void)							\
     ({ int *__futex = (futex);					\
        int __oldval = atomic_exchange_rel (__futex, 0);		\
        if (__builtin_expect (__oldval & FUTEX_WAITERS, 0))	\
 	 lll_futex_wake (__futex, 1, private);			\
     })
 #define lll_robust_unlock(futex, private) \
   __lll_robust_unlock(&(futex), private)


 #define lll_islocked(futex) \
   (futex != 0)


 /* Our internal lock implementation is identical to the binary-compatible
    mutex implementation. */

 /* Initializers for lock.  */
 #define LLL_LOCK_INITIALIZER		(0)
 #define LLL_LOCK_INITIALIZER_LOCKED	(1)

 /* The states of a lock are:
     0  -  untaken
     1  -  taken by one user
    >1  -  taken by more users */

 /* The kernel notifies a process which uses CLONE_CLEARTID via futex
    wakeup when the clone terminates.  The memory location contains the
    thread ID while the clone is running and is reset to zero
    afterwards.	*/
 #define lll_wait_tid(tid) \
   do {					\
     __typeof (tid) __tid;		\
     while ((__tid = (tid)) != 0)	\
       lll_futex_wait (&(tid), __tid, LLL_SHARED);\
   } while (0)

 extern int __lll_timedwait_tid (int *, const struct timespec *)
      attribute_hidden;

 #define lll_timedwait_tid(tid, abstime) \
   ({							\
     int __res = 0;					\
     if ((tid) != 0)					\
       __res = __lll_timedwait_tid (&(tid), (abstime));	\
     __res;						\
   })

 #endif	/* lowlevellock.h */
	/* Copyright (C) 2005, 2006, 2007, 2008, 2009 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, write to the Free
	Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
	02111-1307 USA. */

	#ifndef _LOWLEVELLOCK_H
	#define _LOWLEVELLOCK_H 1

	#include <time.h>
	#include <sys/param.h>
	#include <bits/pthreadtypes.h>
	#include <atomic.h>
	#include <sysdep.h>
	#include <kernel-features.h>

	#define FUTEX_WAIT 0
	#define FUTEX_WAKE 1
	#define FUTEX_REQUEUE 3
	#define FUTEX_CMP_REQUEUE 4
	#define FUTEX_WAKE_OP 5
	#define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE ((4 << 24) \| 1)
	#define FUTEX_LOCK_PI 6
	#define FUTEX_UNLOCK_PI 7
	#define FUTEX_TRYLOCK_PI 8
	#define FUTEX_WAIT_BITSET 9
	#define FUTEX_WAKE_BITSET 10
	#define FUTEX_PRIVATE_FLAG 128
	#define FUTEX_CLOCK_REALTIME 256

	#define FUTEX_BITSET_MATCH_ANY 0xffffffff

	/* Values for 'private' parameter of locking macros. Yes, the
	definition seems to be backwards. But it is not. The bit will be
	reversed before passing to the system call. */
	#define LLL_PRIVATE 0
	#define LLL_SHARED FUTEX_PRIVATE_FLAG


	#if !defined NOT_IN_libc \|\| defined IS_IN_rtld
	/* In libc.so or ld.so all futexes are private. */
	# ifdef __ASSUME_PRIVATE_FUTEX
	# define __lll_private_flag(fl, private) \
	((fl) \| FUTEX_PRIVATE_FLAG)
	# else
	# define __lll_private_flag(fl, private) \
	((fl) \| THREAD_GETMEM (THREAD_SELF, header.private_futex))
	# endif
	#else
	# ifdef __ASSUME_PRIVATE_FUTEX
	# define __lll_private_flag(fl, private) \
	(((fl) \| FUTEX_PRIVATE_FLAG) ^ (private))
	# else
	# define __lll_private_flag(fl, private) \
	(__builtin_constant_p (private) \
	? ((private) == 0 \
	? ((fl) \| THREAD_GETMEM (THREAD_SELF, header.private_futex)) \
	: (fl)) \
	: ((fl) \| (((private) ^ FUTEX_PRIVATE_FLAG) \
	& THREAD_GETMEM (THREAD_SELF, header.private_futex))))
	# endif
	#endif


	#define lll_futex_wait(futexp, val, private) \
	lll_futex_timed_wait(futexp, val, NULL, private)

	#define lll_futex_timed_wait(futexp, val, timespec, private) \
	({ \
	INTERNAL_SYSCALL_DECL (__err); \
	long int __ret; \
	__ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp), \
	__lll_private_flag (FUTEX_WAIT, private), \
	(val), (timespec)); \
	__ret; \
	})

	#define lll_futex_wake(futexp, nr, private) \
	({ \
	INTERNAL_SYSCALL_DECL (__err); \
	long int __ret; \
	__ret = INTERNAL_SYSCALL (futex, __err, 4, (futexp), \
	__lll_private_flag (FUTEX_WAKE, private), \
	(nr), 0); \
	__ret; \
	})

	#define lll_robust_dead(futexv, private) \
	do \
	{ \
	int *__futexp = &(futexv); \
	atomic_or (__futexp, FUTEX_OWNER_DIED); \
	lll_futex_wake (__futexp, 1, private); \
	} \
	while (0)

	/* Returns non-zero if error happened, zero if success. */
	#define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \
	({ \
	INTERNAL_SYSCALL_DECL (__err); \
	long int __ret; \
	__ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \
	__lll_private_flag (FUTEX_CMP_REQUEUE, private),\
	(nr_wake), (nr_move), (mutex), (val)); \
	INTERNAL_SYSCALL_ERROR_P (__ret, __err); \
	})


	/* Returns non-zero if error happened, zero if success. */
	#define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \
	({ \
	INTERNAL_SYSCALL_DECL (__err); \
	long int __ret; \
	__ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \
	__lll_private_flag (FUTEX_WAKE_OP, private), \
	(nr_wake), (nr_wake2), (futexp2), \
	FUTEX_OP_CLEAR_WAKE_IF_GT_ONE); \
	INTERNAL_SYSCALL_ERROR_P (__ret, __err); \
	})


	#define lll_trylock(lock) \
	atomic_compare_and_exchange_val_acq(&(lock), 1, 0)

	#define lll_cond_trylock(lock) \
	atomic_compare_and_exchange_val_acq(&(lock), 2, 0)

	#define __lll_robust_trylock(futex, id) \
	(atomic_compare_and_exchange_val_acq (futex, id, 0) != 0)
	#define lll_robust_trylock(lock, id) \
	__lll_robust_trylock (&(lock), id)

	extern void __lll_lock_wait_private (int *futex) attribute_hidden;
	extern void __lll_lock_wait (int *futex, int private) attribute_hidden;
	extern int __lll_robust_lock_wait (int *futex, int private) attribute_hidden;

	#define __lll_lock(futex, private) \
	((void) ({ \
	int *__futex = (futex); \
	if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, \
	1, 0), 0)) \
	{ \
	if (__builtin_constant_p (private) && (private) == LLL_PRIVATE) \
	__lll_lock_wait_private (__futex); \
	else \
	__lll_lock_wait (__futex, private); \
	} \
	}))
	#define lll_lock(futex, private) __lll_lock (&(futex), private)


	#define __lll_robust_lock(futex, id, private) \
	({ \
	int *__futex = (futex); \
	int __val = 0; \
	\
	if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id, \
	0), 0)) \
	__val = __lll_robust_lock_wait (__futex, private); \
	__val; \
	})
	#define lll_robust_lock(futex, id, private) \
	__lll_robust_lock (&(futex), id, private)


	#define __lll_cond_lock(futex, private) \
	((void) ({ \
	int *__futex = (futex); \
	if (__builtin_expect (atomic_exchange_acq (__futex, 2), 0)) \
	__lll_lock_wait (__futex, private); \
	}))
	#define lll_cond_lock(futex, private) __lll_cond_lock (&(futex), private)


	#define lll_robust_cond_lock(futex, id, private) \
	__lll_robust_lock (&(futex), (id) \| FUTEX_WAITERS, private)


	extern int __lll_timedlock_wait (int futex, const struct timespec ,
	int private) attribute_hidden;
	extern int __lll_robust_timedlock_wait (int futex, const struct timespec ,
	int private) attribute_hidden;

	#define __lll_timedlock(futex, abstime, private) \
	({ \
	int *__futex = (futex); \
	int __val = 0; \
	\
	if (__builtin_expect (atomic_exchange_acq (__futex, 1), 0)) \
	__val = __lll_timedlock_wait (__futex, abstime, private); \
	__val; \
	})
	#define lll_timedlock(futex, abstime, private) \
	__lll_timedlock (&(futex), abstime, private)


	#define __lll_robust_timedlock(futex, abstime, id, private) \
	({ \
	int *__futex = (futex); \
	int __val = 0; \
	\
	if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id, \
	0), 0)) \
	__val = __lll_robust_timedlock_wait (__futex, abstime, private); \
	__val; \
	})
	#define lll_robust_timedlock(futex, abstime, id, private) \
	__lll_robust_timedlock (&(futex), abstime, id, private)


	#define __lll_unlock(futex, private) \
	(void) \
	({ int *__futex = (futex); \
	int __oldval = atomic_exchange_rel (__futex, 0); \
	if (__builtin_expect (__oldval > 1, 0)) \
	lll_futex_wake (__futex, 1, private); \
	})
	#define lll_unlock(futex, private) __lll_unlock(&(futex), private)


	#define __lll_robust_unlock(futex, private) \
	(void) \
	({ int *__futex = (futex); \
	int __oldval = atomic_exchange_rel (__futex, 0); \
	if (__builtin_expect (__oldval & FUTEX_WAITERS, 0)) \
	lll_futex_wake (__futex, 1, private); \
	})
	#define lll_robust_unlock(futex, private) \
	__lll_robust_unlock(&(futex), private)


	#define lll_islocked(futex) \
	(futex != 0)


	/* Our internal lock implementation is identical to the binary-compatible
	mutex implementation. */

	/* Initializers for lock. */
	#define LLL_LOCK_INITIALIZER (0)
	#define LLL_LOCK_INITIALIZER_LOCKED (1)

	/* The states of a lock are:
	0 - untaken
	1 - taken by one user
	>1 - taken by more users */

	/* The kernel notifies a process which uses CLONE_CLEARTID via futex
	wakeup when the clone terminates. The memory location contains the
	thread ID while the clone is running and is reset to zero
	afterwards. */
	#define lll_wait_tid(tid) \
	do { \
	__typeof (tid) __tid; \
	while ((__tid = (tid)) != 0) \
	lll_futex_wait (&(tid), __tid, LLL_SHARED);\
	} while (0)

	extern int __lll_timedwait_tid (int , const struct timespec )
	attribute_hidden;

	#define lll_timedwait_tid(tid, abstime) \
	({ \
	int __res = 0; \
	if ((tid) != 0) \
	__res = __lll_timedwait_tid (&(tid), (abstime)); \
	__res; \
	})

	#endif /* lowlevellock.h */