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yaml
---
r: 147435
b: refs/heads/master
c: 3611dfb
h: refs/heads/master
i:
  147433: 23df06c
  147431: 1af177e
v: v3
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Ingo Molnar committed May 6, 2009
1 parent 131b986 commit 9090e15
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Showing 4 changed files with 30 additions and 29 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 16c8a10932aef971292c9570eb5f60b5d4e83ed2
refs/heads/master: 3611dfb8eda847c1c8e1a052f57206f7fddc6a7c
24 changes: 1 addition & 23 deletions trunk/include/linux/mutex.h
Original file line number Diff line number Diff line change
Expand Up @@ -150,28 +150,6 @@ extern int __must_check mutex_lock_killable(struct mutex *lock);
*/
extern int mutex_trylock(struct mutex *lock);
extern void mutex_unlock(struct mutex *lock);

/**
* atomic_dec_and_mutex_lock - return holding mutex if we dec to 0
* @cnt: the atomic which we are to dec
* @lock: the mutex to return holding if we dec to 0
*
* return true and hold lock if we dec to 0, return false otherwise
*/
static inline int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock)
{
/* dec if we can't possibly hit 0 */
if (atomic_add_unless(cnt, -1, 1))
return 0;
/* we might hit 0, so take the lock */
mutex_lock(lock);
if (!atomic_dec_and_test(cnt)) {
/* when we actually did the dec, we didn't hit 0 */
mutex_unlock(lock);
return 0;
}
/* we hit 0, and we hold the lock */
return 1;
}
extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock);

#endif
25 changes: 24 additions & 1 deletion trunk/kernel/mutex.c
Original file line number Diff line number Diff line change
Expand Up @@ -471,5 +471,28 @@ int __sched mutex_trylock(struct mutex *lock)

return ret;
}

EXPORT_SYMBOL(mutex_trylock);

/**
* atomic_dec_and_mutex_lock - return holding mutex if we dec to 0
* @cnt: the atomic which we are to dec
* @lock: the mutex to return holding if we dec to 0
*
* return true and hold lock if we dec to 0, return false otherwise
*/
int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock)
{
/* dec if we can't possibly hit 0 */
if (atomic_add_unless(cnt, -1, 1))
return 0;
/* we might hit 0, so take the lock */
mutex_lock(lock);
if (!atomic_dec_and_test(cnt)) {
/* when we actually did the dec, we didn't hit 0 */
mutex_unlock(lock);
return 0;
}
/* we hit 0, and we hold the lock */
return 1;
}
EXPORT_SYMBOL(atomic_dec_and_mutex_lock);
8 changes: 4 additions & 4 deletions trunk/kernel/rtmutex.c
Original file line number Diff line number Diff line change
Expand Up @@ -864,9 +864,9 @@ int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock,
EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible);

/**
* rt_mutex_lock_interruptible_ktime - lock a rt_mutex interruptible
* the timeout structure is provided
* by the caller
* rt_mutex_timed_lock - lock a rt_mutex interruptible
* the timeout structure is provided
* by the caller
*
* @lock: the rt_mutex to be locked
* @timeout: timeout structure or NULL (no timeout)
Expand Down Expand Up @@ -913,7 +913,7 @@ void __sched rt_mutex_unlock(struct rt_mutex *lock)
}
EXPORT_SYMBOL_GPL(rt_mutex_unlock);

/***
/**
* rt_mutex_destroy - mark a mutex unusable
* @lock: the mutex to be destroyed
*
Expand Down

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