diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/rwsem-spinlock.h | 3 | ||||
| -rw-r--r-- | include/linux/rwsem.h | 25 |
2 files changed, 27 insertions, 1 deletions
diff --git a/include/linux/rwsem-spinlock.h b/include/linux/rwsem-spinlock.h index 3087c5c101f4..f4ac435bf141 100644 --- a/include/linux/rwsem-spinlock.h +++ b/include/linux/rwsem-spinlock.h @@ -54,9 +54,12 @@ struct rw_semaphore { extern void FASTCALL(init_rwsem(struct rw_semaphore *sem)); extern void FASTCALL(__down_read(struct rw_semaphore *sem)); +extern int FASTCALL(__down_read_trylock(struct rw_semaphore *sem)); extern void FASTCALL(__down_write(struct rw_semaphore *sem)); +extern int FASTCALL(__down_write_trylock(struct rw_semaphore *sem)); extern void FASTCALL(__up_read(struct rw_semaphore *sem)); extern void FASTCALL(__up_write(struct rw_semaphore *sem)); +extern void FASTCALL(__downgrade_write(struct rw_semaphore *sem)); #endif /* __KERNEL__ */ #endif /* _LINUX_RWSEM_SPINLOCK_H */ diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 320138d6643d..4a7e2bb0d7c4 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -46,6 +46,18 @@ static inline void down_read(struct rw_semaphore *sem) } /* + * trylock for reading -- returns 1 if successful, 0 if contention + */ +static inline int down_read_trylock(struct rw_semaphore *sem) +{ + int ret; + rwsemtrace(sem,"Entering down_read_trylock"); + ret = __down_read_trylock(sem); + rwsemtrace(sem,"Leaving down_read_trylock"); + return ret; +} + +/* * lock for writing */ static inline void down_write(struct rw_semaphore *sem) @@ -56,6 +68,18 @@ static inline void down_write(struct rw_semaphore *sem) } /* + * trylock for writing -- returns 1 if successful, 0 if contention + */ +static inline int down_write_trylock(struct rw_semaphore *sem) +{ + int ret; + rwsemtrace(sem,"Entering down_write_trylock"); + ret = __down_write_trylock(sem); + rwsemtrace(sem,"Leaving down_write_trylock"); + return ret; +} + +/* * release a read lock */ static inline void up_read(struct rw_semaphore *sem) @@ -85,6 +109,5 @@ static inline void downgrade_write(struct rw_semaphore *sem) rwsemtrace(sem,"Leaving downgrade_write"); } - #endif /* __KERNEL__ */ #endif /* _LINUX_RWSEM_H */ |