[thirdparty/glibc.git] / ports / sysdeps / unix / sysv / linux / microblaze / nptl / lowlevellock.h

/* Copyright (C) 2005-2014 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 _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>
#include <tls.h>        /* Need THREAD_*, and header.*.  */

#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_WAIT_REQUEUE_PI           11
#define FUTEX_CMP_REQUEUE_PI            12
#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, (long) (futexp),                \
                  __lll_private_flag (FUTEX_WAIT, private),                    \
                  (val), (timespec));                                          \
    __ret;                                                                     \
  })

#define lll_futex_timed_wait_bitset(futexp, val, timespec, clockbit, private)  \
  ({                                                                           \
    INTERNAL_SYSCALL_DECL (__err);                                             \
    long int __ret;                                                            \
    int __op = FUTEX_WAIT_BITSET | clockbit;                                   \
    __ret = INTERNAL_SYSCALL (futex, __err, 6, (long) (futexp),                \
                  __lll_private_flag (__op, private),                          \
                  (val), (timespec), NULL /* Unused.  */,                      \
                  FUTEX_BITSET_MATCH_ANY);                                     \
    __ret;                                                                     \
  })

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

/* Priority Inheritance support.  */
#define lll_futex_wait_requeue_pi(futexp, val, mutex, private)                 \
  lll_futex_timed_wait_requeue_pi (futexp, val, NULL, 0, mutex, private)

#define lll_futex_timed_wait_requeue_pi(futexp, val, timespec, clockbit,       \
                                        mutex, private)                        \
  ({                                                                           \
    INTERNAL_SYSCALL_DECL (__err);                                             \
    long int __ret;                                                            \
    int __op = FUTEX_WAIT_REQUEUE_PI | clockbit;                               \
                                                                               \
    __ret = INTERNAL_SYSCALL (futex, __err, 5, (futexp),                       \
                  __lll_private_flag (__op, private),                          \
                  (val), (timespec), mutex);                                   \
    __ret;                                                                     \
  })

#define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex, val, priv)   \
  ({                                                                           \
    INTERNAL_SYSCALL_DECL (__err);                                             \
    long int __ret;                                                            \
                                                                               \
    __ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp),                       \
                  __lll_private_flag (FUTEX_CMP_REQUEUE_PI, priv),             \
                  (nr_wake), (nr_move), (mutex), (val));                       \
    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) != 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)

static inline void __attribute__ ((always_inline))
__lll_cond_lock (int *futex, int private)
{
    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;

static inline int __attribute__ ((always_inline))
__lll_timedlock (int *futex, const struct timespec *abstime, int private)
{
  int result = 0;
  if (__builtin_expect (atomic_compare_and_exchange_val_acq (futex, 1, 0), 0) != 0)
    result = __lll_timedlock_wait (futex, abstime, private);
  return result;
}
#define lll_timedlock(futex, abstime, private)                                 \
  __lll_timedlock (&(futex), abstime, private)

static inline int __attribute__ ((always_inline))
__lll_robust_timedlock (int *futex, const struct timespec *abstime,
                        int id, int private)
{
  int result = 0;
  if (__builtin_expect (atomic_compare_and_exchange_bool_acq (futex, id, 0), 0))
    result = __lll_robust_timedlock_wait (futex, abstime, private);
  return result;
}
#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 __val = atomic_exchange_rel (__futex, 0);                              \
                                                                               \
    if (__builtin_expect (__val > 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 __val = atomic_exchange_rel (__futex, 0);                              \
                                                                               \
    if (__builtin_expect (__val & 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_CHILD_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.  */
Commit	Line	Data
d4697bc9	1	/* Copyright (C) 2005-2014 Free Software Foundation, Inc.
7756ba9d DH	2
	3	This file is part of the GNU C Library.
	4
	5	The GNU C Library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
	9
	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public
	16	License along with the GNU C Library; if not, see
	17	<http://www.gnu.org/licenses/>. */
	18
	19	#ifndef _LOWLEVELLOCK_H
	20	#define _LOWLEVELLOCK_H 1
	21
	22	#include <time.h>
	23	#include <sys/param.h>
	24	#include <bits/pthreadtypes.h>
	25	#include <atomic.h>
	26	#include <sysdep.h>
	27	#include <kernel-features.h>
	28	#include <tls.h> /* Need THREAD_, and header.. */
	29
	30	#define FUTEX_WAIT 0
	31	#define FUTEX_WAKE 1
	32	#define FUTEX_REQUEUE 3
	33	#define FUTEX_CMP_REQUEUE 4
	34	#define FUTEX_WAKE_OP 5
	35	#define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE ((4 << 24) \| 1)
	36	#define FUTEX_LOCK_PI 6
	37	#define FUTEX_UNLOCK_PI 7
	38	#define FUTEX_TRYLOCK_PI 8
	39	#define FUTEX_WAIT_BITSET 9
	40	#define FUTEX_WAKE_BITSET 10
	41	#define FUTEX_WAIT_REQUEUE_PI 11
	42	#define FUTEX_CMP_REQUEUE_PI 12
	43	#define FUTEX_PRIVATE_FLAG 128
	44	#define FUTEX_CLOCK_REALTIME 256
	45
	46	#define FUTEX_BITSET_MATCH_ANY 0xffffffff
	47
	48	/* Values for 'private' parameter of locking macros. Yes, the
	49	definition seems to be backwards. But it is not. The bit will be
	50	reversed before passing to the system call. */
	51	#define LLL_PRIVATE 0
	52	#define LLL_SHARED FUTEX_PRIVATE_FLAG
	53
	54
	55	#if !defined NOT_IN_libc \|\| defined IS_IN_rtld
	56	/* In libc.so or ld.so all futexes are private. */
	57	# ifdef __ASSUME_PRIVATE_FUTEX
	58	# define __lll_private_flag(fl, private) \
	59	((fl) \| FUTEX_PRIVATE_FLAG)
	60	# else
	61	# define __lll_private_flag(fl, private) \
	62	((fl) \| THREAD_GETMEM (THREAD_SELF, header.private_futex))
	63	# endif
	64	#else
	65	# ifdef __ASSUME_PRIVATE_FUTEX
66	# define __lll_private_flag(fl, private) \
67	(((fl) \| FUTEX_PRIVATE_FLAG) ^ (private))
68	# else
69	# define __lll_private_flag(fl, private) \
70	(__builtin_constant_p (private) \
71	? ((private) == 0 \
72	? ((fl) \| THREAD_GETMEM (THREAD_SELF, header.private_futex)) \
73	: (fl)) \
74	: ((fl) \| (((private) ^ FUTEX_PRIVATE_FLAG) \
75	& THREAD_GETMEM (THREAD_SELF, header.private_futex))))
76	# endif
77	#endif
78
79
80	#define lll_futex_wait(futexp, val, private) \
81	lll_futex_timed_wait (futexp, val, NULL, private)
82
83	#define lll_futex_timed_wait(futexp, val, timespec, private) \
84	({ \
85	INTERNAL_SYSCALL_DECL (__err); \
86	long int __ret; \
87	__ret = INTERNAL_SYSCALL (futex, __err, 4, (long) (futexp), \
88	__lll_private_flag (FUTEX_WAIT, private), \
89	(val), (timespec)); \
c396afdf	90	__ret; \
7756ba9d DH	91	})
	92
	93	#define lll_futex_timed_wait_bitset(futexp, val, timespec, clockbit, private) \
	94	({ \
	95	INTERNAL_SYSCALL_DECL (__err); \
	96	long int __ret; \
	97	int __op = FUTEX_WAIT_BITSET \| clockbit; \
	98	__ret = INTERNAL_SYSCALL (futex, __err, 6, (long) (futexp), \
	99	__lll_private_flag (__op, private), \
	100	(val), (timespec), NULL /* Unused. */, \
	101	FUTEX_BITSET_MATCH_ANY); \
c396afdf	102	__ret; \
7756ba9d DH	103	})
	104
	105	#define lll_futex_wake(futexp, nr, private) \
	106	({ \
	107	INTERNAL_SYSCALL_DECL (__err); \
	108	long int __ret; \
	109	__ret = INTERNAL_SYSCALL (futex, __err, 4, (long) (futexp), \
	110	__lll_private_flag (FUTEX_WAKE, private), \
	111	(nr), 0); \
c396afdf	112	__ret; \
7756ba9d DH	113	})
	114
	115	#define lll_robust_dead(futexv, private) \
	116	do \
	117	{ \
	118	int *__futexp = &(futexv); \
	119	atomic_or (__futexp, FUTEX_OWNER_DIED); \
	120	lll_futex_wake (__futexp, 1, private); \
	121	} \
	122	while (0)
	123
	124	/* Returns non-zero if error happened, zero if success. */
	125	#define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \
	126	({ \
	127	INTERNAL_SYSCALL_DECL (__err); \
	128	long int __ret; \
	129	__ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \
	130	__lll_private_flag (FUTEX_CMP_REQUEUE, private), \
	131	(nr_wake), (nr_move), (mutex), (val)); \
	132	INTERNAL_SYSCALL_ERROR_P (__ret, __err); \
	133	})
	134
	135
	136	/* Returns non-zero if error happened, zero if success. */
	137	#define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \
	138	({ \
	139	INTERNAL_SYSCALL_DECL (__err); \
	140	long int __ret; \
	141	\
	142	__ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \
	143	__lll_private_flag (FUTEX_WAKE_OP, private), \
	144	(nr_wake), (nr_wake2), (futexp2), \
	145	FUTEX_OP_CLEAR_WAKE_IF_GT_ONE); \
	146	INTERNAL_SYSCALL_ERROR_P (__ret, __err); \
	147	})
	148
	149	/* Priority Inheritance support. */
	150	#define lll_futex_wait_requeue_pi(futexp, val, mutex, private) \
	151	lll_futex_timed_wait_requeue_pi (futexp, val, NULL, 0, mutex, private)
	152
	153	#define lll_futex_timed_wait_requeue_pi(futexp, val, timespec, clockbit, \
	154	mutex, private) \
	155	({ \
	156	INTERNAL_SYSCALL_DECL (__err); \
	157	long int __ret; \
	158	int __op = FUTEX_WAIT_REQUEUE_PI \| clockbit; \
	159	\
	160	__ret = INTERNAL_SYSCALL (futex, __err, 5, (futexp), \
	161	__lll_private_flag (__op, private), \
	162	(val), (timespec), mutex); \
c396afdf	163	__ret; \
7756ba9d DH	164	})
	165
	166	#define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex, val, priv) \
	167	({ \
	168	INTERNAL_SYSCALL_DECL (__err); \
	169	long int __ret; \
	170	\
	171	__ret = INTERNAL_SYSCALL (futex, __err, 6, (futexp), \
	172	__lll_private_flag (FUTEX_CMP_REQUEUE_PI, priv), \
	173	(nr_wake), (nr_move), (mutex), (val)); \
	174	INTERNAL_SYSCALL_ERROR_P (__ret, __err); \
	175	})
	176
	177	#define lll_trylock(lock) \
	178	atomic_compare_and_exchange_val_acq(&(lock), 1, 0)
	179
	180	#define lll_cond_trylock(lock) \
	181	atomic_compare_and_exchange_val_acq(&(lock), 2, 0)
	182
	183	#define __lll_robust_trylock(futex, id) \
	184	(atomic_compare_and_exchange_val_acq (futex, id, 0) != 0)
	185	#define lll_robust_trylock(lock, id) \
	186	__lll_robust_trylock (&(lock), id)
	187
	188	extern void __lll_lock_wait_private (int *futex) attribute_hidden;
	189	extern void __lll_lock_wait (int *futex, int private) attribute_hidden;
	190	extern int __lll_robust_lock_wait (int *futex, int private) attribute_hidden;
	191
	192	#define __lll_lock(futex, private) \
	193	((void) ({ \
	194	int *__futex = (futex); \
	195	if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 1, 0), \
	196	0) != 0) \
	197	{ \
	198	if (__builtin_constant_p (private) && (private) == LLL_PRIVATE) \
	199	__lll_lock_wait_private (__futex); \
	200	else \
	201	__lll_lock_wait (__futex, private); \
	202	} \
	203	}))
	204	#define lll_lock(futex, private) __lll_lock (&(futex), private)
	205
	206	#define __lll_robust_lock(futex, id, private) \
	207	({ \
	208	int *__futex = (futex); \
	209	int __val = 0; \
	210	\
	211	if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id, \
	212	0), 0)) \
	213	__val = __lll_robust_lock_wait (__futex, private); \
	214	__val; \
	215	})
	216	#define lll_robust_lock(futex, id, private) \
	217	__lll_robust_lock (&(futex), id, private)
	218
	219	static inline void __attribute__ ((always_inline))
	220	__lll_cond_lock (int *futex, int private)
	221	{
	222	if (__builtin_expect (atomic_exchange_acq (futex, 2), 0))
	223	__lll_lock_wait (futex, private);
	224	}
	225	#define lll_cond_lock(futex, private) __lll_cond_lock (&(futex), private)
	226
	227	#define lll_robust_cond_lock(futex, id, private) \
228	__lll_robust_lock (&(futex), (id) \| FUTEX_WAITERS, private)
229
230
231	extern int __lll_timedlock_wait (int futex, const struct timespec ,
232	int private) attribute_hidden;
233	extern int __lll_robust_timedlock_wait (int futex, const struct timespec ,
234	int private) attribute_hidden;
235
236	static inline int __attribute__ ((always_inline))
237	__lll_timedlock (int futex, const struct timespec abstime, int private)
238	{
239	int result = 0;
240	if (__builtin_expect (atomic_compare_and_exchange_val_acq (futex, 1, 0), 0) != 0)
241	result = __lll_timedlock_wait (futex, abstime, private);
242	return result;
243	}
244	#define lll_timedlock(futex, abstime, private) \
245	__lll_timedlock (&(futex), abstime, private)
246
247	static inline int __attribute__ ((always_inline))
248	__lll_robust_timedlock (int futex, const struct timespec abstime,
249	int id, int private)
250	{
251	int result = 0;
252	if (__builtin_expect (atomic_compare_and_exchange_bool_acq (futex, id, 0), 0))
253	result = __lll_robust_timedlock_wait (futex, abstime, private);
254	return result;
255	}
256	#define lll_robust_timedlock(futex, abstime, id, private) \
257	__lll_robust_timedlock (&(futex), abstime, id, private)
258
259	#define __lll_unlock(futex, private) \
260	((void) ({ \
261	int *__futex = (futex); \
262	int __val = atomic_exchange_rel (__futex, 0); \
263	\
264	if (__builtin_expect (__val > 1, 0)) \
265	lll_futex_wake (__futex, 1, private); \
266	}))
267	#define lll_unlock(futex, private) __lll_unlock(&(futex), private)
268
269	#define __lll_robust_unlock(futex, private) \
270	((void) ({ \
271	int *__futex = (futex); \
272	int __val = atomic_exchange_rel (__futex, 0); \
273	\
274	if (__builtin_expect (__val & FUTEX_WAITERS, 0)) \
275	lll_futex_wake (__futex, 1, private); \
276	}))
277	#define lll_robust_unlock(futex, private) \
278	__lll_robust_unlock(&(futex), private)
279
280	#define lll_islocked(futex) \
281	(futex != 0)
282
283	/* Our internal lock implementation is identical to the binary-compatible
284	mutex implementation. */
285
286	/* Initializers for lock. */
287	#define LLL_LOCK_INITIALIZER (0)
288	#define LLL_LOCK_INITIALIZER_LOCKED (1)
289
290	/* The states of a lock are:
291	0 - untaken
292	1 - taken by one user
293	>1 - taken by more users. */
294
295	/* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex
296	wakeup when the clone terminates. The memory location contains the
297	thread ID while the clone is running and is reset to zero
298	afterwards. */
299	#define lll_wait_tid(tid) \
300	do { \
301	__typeof (tid) __tid; \
302	while ((__tid = (tid)) != 0) \
303	lll_futex_wait (&(tid), __tid, LLL_SHARED); \
304	} while (0)
305
306	extern int __lll_timedwait_tid (int , const struct timespec )
307	attribute_hidden;
308
309	#define lll_timedwait_tid(tid, abstime) \
310	({ \
311	int __res = 0; \
312	if ((tid) != 0) \
313	__res = __lll_timedwait_tid (&(tid), (abstime)); \
314	__res; \
315	})
316
317	#endif /* lowlevellock.h. */