diff options
Diffstat (limited to 'ANDROID_3.4.5/include/linux/rwsem.h')
-rw-r--r-- | ANDROID_3.4.5/include/linux/rwsem.h | 133 |
1 files changed, 0 insertions, 133 deletions
diff --git a/ANDROID_3.4.5/include/linux/rwsem.h b/ANDROID_3.4.5/include/linux/rwsem.h deleted file mode 100644 index 54bd7cd7..00000000 --- a/ANDROID_3.4.5/include/linux/rwsem.h +++ /dev/null @@ -1,133 +0,0 @@ -/* rwsem.h: R/W semaphores, public interface - * - * Written by David Howells (dhowells@redhat.com). - * Derived from asm-i386/semaphore.h - */ - -#ifndef _LINUX_RWSEM_H -#define _LINUX_RWSEM_H - -#include <linux/linkage.h> - -#include <linux/types.h> -#include <linux/kernel.h> -#include <linux/list.h> -#include <linux/spinlock.h> - -#include <linux/atomic.h> - -struct rw_semaphore; - -#ifdef CONFIG_RWSEM_GENERIC_SPINLOCK -#include <linux/rwsem-spinlock.h> /* use a generic implementation */ -#else -/* All arch specific implementations share the same struct */ -struct rw_semaphore { - long count; - raw_spinlock_t wait_lock; - struct list_head wait_list; -#ifdef CONFIG_DEBUG_LOCK_ALLOC - struct lockdep_map dep_map; -#endif -}; - -extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem); -extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem); -extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *); -extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem); - -/* Include the arch specific part */ -#include <asm/rwsem.h> - -/* In all implementations count != 0 means locked */ -static inline int rwsem_is_locked(struct rw_semaphore *sem) -{ - return sem->count != 0; -} - -#endif - -/* Common initializer macros and functions */ - -#ifdef CONFIG_DEBUG_LOCK_ALLOC -# define __RWSEM_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname } -#else -# define __RWSEM_DEP_MAP_INIT(lockname) -#endif - -#define __RWSEM_INITIALIZER(name) \ - { RWSEM_UNLOCKED_VALUE, \ - __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \ - LIST_HEAD_INIT((name).wait_list) \ - __RWSEM_DEP_MAP_INIT(name) } - -#define DECLARE_RWSEM(name) \ - struct rw_semaphore name = __RWSEM_INITIALIZER(name) - -extern void __init_rwsem(struct rw_semaphore *sem, const char *name, - struct lock_class_key *key); - -#define init_rwsem(sem) \ -do { \ - static struct lock_class_key __key; \ - \ - __init_rwsem((sem), #sem, &__key); \ -} while (0) - -/* - * lock for reading - */ -extern void down_read(struct rw_semaphore *sem); - -/* - * trylock for reading -- returns 1 if successful, 0 if contention - */ -extern int down_read_trylock(struct rw_semaphore *sem); - -/* - * lock for writing - */ -extern void down_write(struct rw_semaphore *sem); - -/* - * trylock for writing -- returns 1 if successful, 0 if contention - */ -extern int down_write_trylock(struct rw_semaphore *sem); - -/* - * release a read lock - */ -extern void up_read(struct rw_semaphore *sem); - -/* - * release a write lock - */ -extern void up_write(struct rw_semaphore *sem); - -/* - * downgrade write lock to read lock - */ -extern void downgrade_write(struct rw_semaphore *sem); - -#ifdef CONFIG_DEBUG_LOCK_ALLOC -/* - * nested locking. NOTE: rwsems are not allowed to recurse - * (which occurs if the same task tries to acquire the same - * lock instance multiple times), but multiple locks of the - * same lock class might be taken, if the order of the locks - * is always the same. This ordering rule can be expressed - * to lockdep via the _nested() APIs, but enumerating the - * subclasses that are used. (If the nesting relationship is - * static then another method for expressing nested locking is - * the explicit definition of lock class keys and the use of - * lockdep_set_class() at lock initialization time. - * See Documentation/lockdep-design.txt for more details.) - */ -extern void down_read_nested(struct rw_semaphore *sem, int subclass); -extern void down_write_nested(struct rw_semaphore *sem, int subclass); -#else -# define down_read_nested(sem, subclass) down_read(sem) -# define down_write_nested(sem, subclass) down_write(sem) -#endif - -#endif /* _LINUX_RWSEM_H */ |