diff options
Diffstat (limited to 'include/linux/wait.h')
| -rw-r--r-- | include/linux/wait.h | 198 |
1 files changed, 175 insertions, 23 deletions
diff --git a/include/linux/wait.h b/include/linux/wait.h index 6788e1a4d4ca..3efc9f3f43a0 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -26,8 +26,8 @@ #include <asm/current.h> typedef struct __wait_queue wait_queue_t; -typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int sync, void *key); -int default_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); +typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int flags, void *key); +int default_wake_function(wait_queue_t *wait, unsigned mode, int flags, void *key); struct __wait_queue { unsigned int flags; @@ -77,7 +77,14 @@ struct task_struct; #define __WAIT_BIT_KEY_INITIALIZER(word, bit) \ { .flags = word, .bit_nr = bit, } -extern void init_waitqueue_head(wait_queue_head_t *q); +extern void __init_waitqueue_head(wait_queue_head_t *q, struct lock_class_key *); + +#define init_waitqueue_head(q) \ + do { \ + static struct lock_class_key __key; \ + \ + __init_waitqueue_head((q), &__key); \ + } while (0) #ifdef CONFIG_LOCKDEP # define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \ @@ -120,12 +127,26 @@ static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new) /* * Used for wake-one threads: */ +static inline void __add_wait_queue_exclusive(wait_queue_head_t *q, + wait_queue_t *wait) +{ + wait->flags |= WQ_FLAG_EXCLUSIVE; + __add_wait_queue(q, wait); +} + static inline void __add_wait_queue_tail(wait_queue_head_t *head, - wait_queue_t *new) + wait_queue_t *new) { list_add_tail(&new->task_list, &head->task_list); } +static inline void __add_wait_queue_tail_exclusive(wait_queue_head_t *q, + wait_queue_t *wait) +{ + wait->flags |= WQ_FLAG_EXCLUSIVE; + __add_wait_queue_tail(q, wait); +} + static inline void __remove_wait_queue(wait_queue_head_t *head, wait_queue_t *old) { @@ -355,6 +376,155 @@ do { \ __ret; \ }) + +#define __wait_event_interruptible_locked(wq, condition, exclusive, irq) \ +({ \ + int __ret = 0; \ + DEFINE_WAIT(__wait); \ + if (exclusive) \ + __wait.flags |= WQ_FLAG_EXCLUSIVE; \ + do { \ + if (likely(list_empty(&__wait.task_list))) \ + __add_wait_queue_tail(&(wq), &__wait); \ + set_current_state(TASK_INTERRUPTIBLE); \ + if (signal_pending(current)) { \ + __ret = -ERESTARTSYS; \ + break; \ + } \ + if (irq) \ + spin_unlock_irq(&(wq).lock); \ + else \ + spin_unlock(&(wq).lock); \ + schedule(); \ + if (irq) \ + spin_lock_irq(&(wq).lock); \ + else \ + spin_lock(&(wq).lock); \ + } while (!(condition)); \ + __remove_wait_queue(&(wq), &__wait); \ + __set_current_state(TASK_RUNNING); \ + __ret; \ +}) + + +/** + * wait_event_interruptible_locked - sleep until a condition gets true + * @wq: the waitqueue to wait on + * @condition: a C expression for the event to wait for + * + * The process is put to sleep (TASK_INTERRUPTIBLE) until the + * @condition evaluates to true or a signal is received. + * The @condition is checked each time the waitqueue @wq is woken up. + * + * It must be called with wq.lock being held. This spinlock is + * unlocked while sleeping but @condition testing is done while lock + * is held and when this macro exits the lock is held. + * + * The lock is locked/unlocked using spin_lock()/spin_unlock() + * functions which must match the way they are locked/unlocked outside + * of this macro. + * + * wake_up_locked() has to be called after changing any variable that could + * change the result of the wait condition. + * + * The function will return -ERESTARTSYS if it was interrupted by a + * signal and 0 if @condition evaluated to true. + */ +#define wait_event_interruptible_locked(wq, condition) \ + ((condition) \ + ? 0 : __wait_event_interruptible_locked(wq, condition, 0, 0)) + +/** + * wait_event_interruptible_locked_irq - sleep until a condition gets true + * @wq: the waitqueue to wait on + * @condition: a C expression for the event to wait for + * + * The process is put to sleep (TASK_INTERRUPTIBLE) until the + * @condition evaluates to true or a signal is received. + * The @condition is checked each time the waitqueue @wq is woken up. + * + * It must be called with wq.lock being held. This spinlock is + * unlocked while sleeping but @condition testing is done while lock + * is held and when this macro exits the lock is held. + * + * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq() + * functions which must match the way they are locked/unlocked outside + * of this macro. + * + * wake_up_locked() has to be called after changing any variable that could + * change the result of the wait condition. + * + * The function will return -ERESTARTSYS if it was interrupted by a + * signal and 0 if @condition evaluated to true. + */ +#define wait_event_interruptible_locked_irq(wq, condition) \ + ((condition) \ + ? 0 : __wait_event_interruptible_locked(wq, condition, 0, 1)) + +/** + * wait_event_interruptible_exclusive_locked - sleep exclusively until a condition gets true + * @wq: the waitqueue to wait on + * @condition: a C expression for the event to wait for + * + * The process is put to sleep (TASK_INTERRUPTIBLE) until the + * @condition evaluates to true or a signal is received. + * The @condition is checked each time the waitqueue @wq is woken up. + * + * It must be called with wq.lock being held. This spinlock is + * unlocked while sleeping but @condition testing is done while lock + * is held and when this macro exits the lock is held. + * + * The lock is locked/unlocked using spin_lock()/spin_unlock() + * functions which must match the way they are locked/unlocked outside + * of this macro. + * + * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag + * set thus when other process waits process on the list if this + * process is awaken further processes are not considered. + * + * wake_up_locked() has to be called after changing any variable that could + * change the result of the wait condition. + * + * The function will return -ERESTARTSYS if it was interrupted by a + * signal and 0 if @condition evaluated to true. + */ +#define wait_event_interruptible_exclusive_locked(wq, condition) \ + ((condition) \ + ? 0 : __wait_event_interruptible_locked(wq, condition, 1, 0)) + +/** + * wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true + * @wq: the waitqueue to wait on + * @condition: a C expression for the event to wait for + * + * The process is put to sleep (TASK_INTERRUPTIBLE) until the + * @condition evaluates to true or a signal is received. + * The @condition is checked each time the waitqueue @wq is woken up. + * + * It must be called with wq.lock being held. This spinlock is + * unlocked while sleeping but @condition testing is done while lock + * is held and when this macro exits the lock is held. + * + * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq() + * functions which must match the way they are locked/unlocked outside + * of this macro. + * + * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag + * set thus when other process waits process on the list if this + * process is awaken further processes are not considered. + * + * wake_up_locked() has to be called after changing any variable that could + * change the result of the wait condition. + * + * The function will return -ERESTARTSYS if it was interrupted by a + * signal and 0 if @condition evaluated to true. + */ +#define wait_event_interruptible_exclusive_locked_irq(wq, condition) \ + ((condition) \ + ? 0 : __wait_event_interruptible_locked(wq, condition, 1, 1)) + + + #define __wait_event_killable(wq, condition, ret) \ do { \ DEFINE_WAIT(__wait); \ @@ -397,25 +567,6 @@ do { \ }) /* - * Must be called with the spinlock in the wait_queue_head_t held. - */ -static inline void add_wait_queue_exclusive_locked(wait_queue_head_t *q, - wait_queue_t * wait) -{ - wait->flags |= WQ_FLAG_EXCLUSIVE; - __add_wait_queue_tail(q, wait); -} - -/* - * Must be called with the spinlock in the wait_queue_head_t held. - */ -static inline void remove_wait_queue_locked(wait_queue_head_t *q, - wait_queue_t * wait) -{ - __remove_wait_queue(q, wait); -} - -/* * These are the old interfaces to sleep waiting for an event. * They are racy. DO NOT use them, use the wait_event* interfaces above. * We plan to remove these interfaces. @@ -463,6 +614,7 @@ int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key); (wait)->private = current; \ (wait)->func = autoremove_wake_function; \ INIT_LIST_HEAD(&(wait)->task_list); \ + (wait)->flags = 0; \ } while (0) /** |