rwlock.c File Reference

Reader/Writer locks. More...

Include dependency graph for rwlock.c:

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Defines
#define	ALLOW_ALL   0
#define	ALLOW_READERS_ONLY   1
Functions
static void	let_others_in (rwlock_t *rwl, int readers_only)
static void	release_spinlock (void *arg)
void	rwlock_initialize (rwlock_t *rwl)
int	_rwlock_write_lock_timeout (rwlock_t *rwl, __u32 usec, int flags)
int	_rwlock_read_lock_timeout (rwlock_t *rwl, __u32 usec, int flags)
void	rwlock_write_unlock (rwlock_t *rwl)
void	rwlock_read_unlock (rwlock_t *rwl)

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Detailed Description

A reader/writer lock can be held by multiple readers at a time. Or it can be exclusively held by a sole writer at a time.

These locks are not recursive. Because technique called direct hand-off is used, neither readers nor writers will suffer starvation.

If there is a writer followed by a reader waiting for the rwlock and the writer times out, all leading readers are automatically woken up and allowed in.

Definition in file rwlock.c.

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