mirror of
				https://sourceware.org/git/glibc.git
				synced 2025-10-31 22:10:34 +03:00 
			
		
		
		
	
		
			
				
	
	
		
			343 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			343 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Copyright (C) 2003-2013 Free Software Foundation, Inc.
 | |
|    This file is part of the GNU C Library.
 | |
|    Contributed by Jakub Jelinek <jakub@redhat.com>, 2003.
 | |
| 
 | |
|    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 <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_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
 | |
| 
 | |
| #ifndef __sparc32_atomic_do_lock
 | |
| /* Delay in spinlock loop.  */
 | |
| extern void __cpu_relax (void);
 | |
| #define BUSY_WAIT_NOP	__cpu_relax ()
 | |
| #endif
 | |
| 
 | |
| #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_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, (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, (futexp),		      \
 | |
| 			      __lll_private_flag (FUTEX_WAKE, private),	      \
 | |
| 			      (nr), 0);					      \
 | |
|     __ret;								      \
 | |
|   })
 | |
| 
 | |
| /* 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);				      \
 | |
|   })
 | |
| 
 | |
| #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.  */
 | |
| #ifdef __sparc32_atomic_do_lock
 | |
| /* Avoid FUTEX_WAKE_OP if supporting pre-v9 CPUs.  */
 | |
| # define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) 1
 | |
| #else
 | |
| # 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);				      \
 | |
|   })
 | |
| #endif
 | |
| 
 | |
| /* 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); 		      \
 | |
|     INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __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);				      \
 | |
|   })
 | |
| 
 | |
| static inline int
 | |
| __attribute__ ((always_inline))
 | |
| __lll_trylock (int *futex)
 | |
| {
 | |
|   return atomic_compare_and_exchange_val_24_acq (futex, 1, 0) != 0;
 | |
| }
 | |
| #define lll_trylock(futex) __lll_trylock (&(futex))
 | |
| 
 | |
| static inline int
 | |
| __attribute__ ((always_inline))
 | |
| __lll_cond_trylock (int *futex)
 | |
| {
 | |
|   return atomic_compare_and_exchange_val_24_acq (futex, 2, 0) != 0;
 | |
| }
 | |
| #define lll_cond_trylock(futex) __lll_cond_trylock (&(futex))
 | |
| 
 | |
| static inline int
 | |
| __attribute__ ((always_inline))
 | |
| __lll_robust_trylock (int *futex, int id)
 | |
| {
 | |
|   return atomic_compare_and_exchange_val_acq (futex, id, 0) != 0;
 | |
| }
 | |
| #define lll_robust_trylock(futex, id) \
 | |
|   __lll_robust_trylock (&(futex), 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;
 | |
| 
 | |
| static inline void
 | |
| __attribute__ ((always_inline))
 | |
| __lll_lock (int *futex, int private)
 | |
| {
 | |
|   int val = atomic_compare_and_exchange_val_24_acq (futex, 1, 0);
 | |
| 
 | |
|   if (__builtin_expect (val != 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)
 | |
| 
 | |
| static inline int
 | |
| __attribute__ ((always_inline))
 | |
| __lll_robust_lock (int *futex, int id, int private)
 | |
| {
 | |
|   int result = 0;
 | |
|   if (atomic_compare_and_exchange_bool_acq (futex, id, 0) != 0)
 | |
|     result = __lll_robust_lock_wait (futex, private);
 | |
|   return result;
 | |
| }
 | |
| #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)
 | |
| {
 | |
|   int val = atomic_compare_and_exchange_val_24_acq (futex, 2, 0);
 | |
| 
 | |
|   if (__builtin_expect (val != 0, 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 val = atomic_compare_and_exchange_val_24_acq (futex, 1, 0);
 | |
|   int result = 0;
 | |
| 
 | |
|   if (__builtin_expect (val != 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 (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(lock, private) \
 | |
|   ((void) ({								      \
 | |
|     int *__futex = &(lock);						      \
 | |
|     int __val = atomic_exchange_24_rel (__futex, 0);			      \
 | |
|     if (__builtin_expect (__val > 1, 0))				      \
 | |
|       lll_futex_wake (__futex, 1, private);				      \
 | |
|   }))
 | |
| 
 | |
| #define lll_robust_unlock(lock, private) \
 | |
|   ((void) ({								      \
 | |
|     int *__futex = &(lock);						      \
 | |
|     int __val = atomic_exchange_rel (__futex, 0);			      \
 | |
|     if (__builtin_expect (__val & FUTEX_WAITERS, 0))			      \
 | |
|       lll_futex_wake (__futex, 1, private);				      \
 | |
|   }))
 | |
| 
 | |
| #define lll_islocked(futex) \
 | |
|   (futex != 0)
 | |
| 
 | |
| /* Initializers for lock.  */
 | |
| #define LLL_LOCK_INITIALIZER		(0)
 | |
| #define LLL_LOCK_INITIALIZER_LOCKED	(1)
 | |
| 
 | |
| /* 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 */
 |