diff options
Diffstat (limited to 'include/linux/wait.h')
| -rw-r--r-- | include/linux/wait.h | 1172 |
1 files changed, 34 insertions, 1138 deletions
diff --git a/include/linux/wait.h b/include/linux/wait.h index 77cba057..f6f5757a 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -2,20 +2,14 @@ #define _LINUX_WAIT_H #include <pthread.h> - #include <linux/bitmap.h> #include <linux/list.h> -#include <linux/lockdep.h> #include <linux/spinlock.h> -//#include <uapi/linux/wait.h> typedef struct __wait_queue wait_queue_t; 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); -/* __wait_queue::flags */ #define WQ_FLAG_EXCLUSIVE 0x01 -#define WQ_FLAG_WOKEN 0x02 struct __wait_queue { unsigned int flags; @@ -24,37 +18,23 @@ struct __wait_queue { struct list_head task_list; }; -struct wait_bit_key { - void *flags; - int bit_nr; -#define WAIT_ATOMIC_T_BIT_NR -1 - unsigned long timeout; -}; - -struct wait_bit_queue { - struct wait_bit_key key; - wait_queue_t wait; -}; - -struct __wait_queue_head { +typedef struct { spinlock_t lock; struct list_head task_list; -}; -typedef struct __wait_queue_head wait_queue_head_t; - -struct task_struct; +} wait_queue_head_t; -/* - * Macros for declaration and initialisaton of the datatypes - */ - -#define __WAITQUEUE_INITIALIZER(name, tsk) { \ - .private = tsk, \ - .func = default_wake_function, \ - .task_list = { NULL, NULL } } +void wake_up(wait_queue_head_t *); +void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state); +void finish_wait(wait_queue_head_t *q, wait_queue_t *wait); +int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); +int default_wake_function(wait_queue_t *wait, unsigned mode, int flags, void *key); #define DECLARE_WAITQUEUE(name, tsk) \ - wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk) + wait_queue_t name = { \ + .private = tsk, \ + .func = default_wake_function, \ + .task_list = { NULL, NULL } \ + } #define __WAIT_QUEUE_HEAD_INITIALIZER(name) { \ .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ @@ -63,178 +43,18 @@ struct task_struct; #define DECLARE_WAIT_QUEUE_HEAD(name) \ wait_queue_head_t name = __WAIT_QUEUE_HEAD_INITIALIZER(name) -#define __WAIT_BIT_KEY_INITIALIZER(word, bit) \ - { .flags = word, .bit_nr = bit, } - -#define __WAIT_ATOMIC_T_KEY_INITIALIZER(p) \ - { .flags = p, .bit_nr = WAIT_ATOMIC_T_BIT_NR, } - -extern void __init_waitqueue_head(wait_queue_head_t *q, const char *name, struct lock_class_key *); - -#define init_waitqueue_head(q) \ - do { \ - static struct lock_class_key __key; \ - \ - __init_waitqueue_head((q), #q, &__key); \ - } while (0) - -#ifdef CONFIG_LOCKDEP -# define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \ - ({ init_waitqueue_head(&name); name; }) -# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \ - wait_queue_head_t name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) -#else -# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name) -#endif - -static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p) -{ - q->flags = 0; - q->private = p; - q->func = default_wake_function; -} - -static inline void -init_waitqueue_func_entry(wait_queue_t *q, wait_queue_func_t func) -{ - q->flags = 0; - q->private = NULL; - q->func = func; -} - -/** - * waitqueue_active -- locklessly test for waiters on the queue - * @q: the waitqueue to test for waiters - * - * returns true if the wait list is not empty - * - * NOTE: this function is lockless and requires care, incorrect usage _will_ - * lead to sporadic and non-obvious failure. - * - * Use either while holding wait_queue_head_t::lock or when used for wakeups - * with an extra smp_mb() like: - * - * CPU0 - waker CPU1 - waiter - * - * for (;;) { - * @cond = true; prepare_to_wait(&wq, &wait, state); - * smp_mb(); // smp_mb() from set_current_state() - * if (waitqueue_active(wq)) if (@cond) - * wake_up(wq); break; - * schedule(); - * } - * finish_wait(&wq, &wait); - * - * Because without the explicit smp_mb() it's possible for the - * waitqueue_active() load to get hoisted over the @cond store such that we'll - * observe an empty wait list while the waiter might not observe @cond. - * - * Also note that this 'optimization' trades a spin_lock() for an smp_mb(), - * which (when the lock is uncontended) are of roughly equal cost. - */ -static inline int waitqueue_active(wait_queue_head_t *q) -{ - return !list_empty(&q->task_list); -} - -/** - * wq_has_sleeper - check if there are any waiting processes - * @wq: wait queue head - * - * Returns true if wq has waiting processes - * - * Please refer to the comment for waitqueue_active. - */ -static inline bool wq_has_sleeper(wait_queue_head_t *wq) -{ - /* - * We need to be sure we are in sync with the - * add_wait_queue modifications to the wait queue. - * - * This memory barrier should be paired with one on the - * waiting side. - */ - smp_mb(); - return waitqueue_active(wq); -} - -extern void add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait); -extern void add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait); -extern void remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait); - -static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new) -{ - list_add(&new->task_list, &head->task_list); -} - -/* - * 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) -{ - 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) +static inline void init_waitqueue_head(wait_queue_head_t *q) { - list_del(&old->task_list); + spin_lock_init(&q->lock); + INIT_LIST_HEAD(&q->task_list); } -typedef int wait_bit_action_f(struct wait_bit_key *, int mode); -void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key); -void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key); -void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr, void *key); -void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr); -void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr); -void __wake_up_bit(wait_queue_head_t *, void *, int); -int __wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, wait_bit_action_f *, unsigned); -int __wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, wait_bit_action_f *, unsigned); -void wake_up_bit(void *, int); -void wake_up_atomic_t(atomic_t *); -int out_of_line_wait_on_bit(void *, int, wait_bit_action_f *, unsigned); -int out_of_line_wait_on_bit_timeout(void *, int, wait_bit_action_f *, unsigned, unsigned long); -int out_of_line_wait_on_bit_lock(void *, int, wait_bit_action_f *, unsigned); -int out_of_line_wait_on_atomic_t(atomic_t *, int (*)(atomic_t *), unsigned); -wait_queue_head_t *bit_waitqueue(void *, int); - -#define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL) -#define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL) -#define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL) -#define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL, 1) -#define wake_up_all_locked(x) __wake_up_locked((x), TASK_NORMAL, 0) - -#define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL) -#define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL) -#define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL) -#define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE, 1) - -/* - * Wakeup macros to be used to report events to the targets. - */ -#define wake_up_poll(x, m) \ - __wake_up(x, TASK_NORMAL, 1, (void *) (m)) -#define wake_up_locked_poll(x, m) \ - __wake_up_locked_key((x), TASK_NORMAL, (void *) (m)) -#define wake_up_interruptible_poll(x, m) \ - __wake_up(x, TASK_INTERRUPTIBLE, 1, (void *) (m)) -#define wake_up_interruptible_sync_poll(x, m) \ - __wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, (void *) (m)) +#define DEFINE_WAIT(name) \ + wait_queue_t name = { \ + .private = current, \ + .func = autoremove_wake_function, \ + .task_list = LIST_HEAD_INIT((name).task_list), \ + } #define ___wait_cond_timeout(condition) \ ({ \ @@ -244,992 +64,68 @@ wait_queue_head_t *bit_waitqueue(void *, int); __cond || !__ret; \ }) -#define ___wait_is_interruptible(state) \ - (!__builtin_constant_p(state) || \ - state == TASK_INTERRUPTIBLE || state == TASK_KILLABLE) \ - -/* - * The below macro ___wait_event() has an explicit shadow of the __ret - * variable when used from the wait_event_*() macros. - * - * This is so that both can use the ___wait_cond_timeout() construct - * to wrap the condition. - * - * The type inconsistency of the wait_event_*() __ret variable is also - * on purpose; we use long where we can return timeout values and int - * otherwise. - */ - #define ___wait_event(wq, condition, state, exclusive, ret, cmd) \ ({ \ - __label__ __out; \ - wait_queue_t __wait; \ - long __ret = ret; /* explicit shadow */ \ - \ - INIT_LIST_HEAD(&__wait.task_list); \ - if (exclusive) \ - __wait.flags = WQ_FLAG_EXCLUSIVE; \ - else \ - __wait.flags = 0; \ + DEFINE_WAIT(__wait); \ + long __ret = ret; \ \ for (;;) { \ - long __int = prepare_to_wait_event(&wq, &__wait, state);\ - \ + prepare_to_wait(&wq, &__wait, state); \ if (condition) \ break; \ - \ - if (___wait_is_interruptible(state) && __int) { \ - __ret = __int; \ - if (exclusive) { \ - abort_exclusive_wait(&wq, &__wait, \ - state, NULL); \ - goto __out; \ - } \ - break; \ - } \ - \ cmd; \ } \ finish_wait(&wq, &__wait); \ -__out: __ret; \ + __ret; \ }) #define __wait_event(wq, condition) \ (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ schedule()) -/** - * wait_event - 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_UNINTERRUPTIBLE) until the - * @condition evaluates to true. The @condition is checked each time - * the waitqueue @wq is woken up. - * - * wake_up() has to be called after changing any variable that could - * change the result of the wait condition. - */ #define wait_event(wq, condition) \ do { \ - might_sleep(); \ if (condition) \ break; \ __wait_event(wq, condition); \ } while (0) -#define __io_wait_event(wq, condition) \ - (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ - io_schedule()) - -/* - * io_wait_event() -- like wait_event() but with io_schedule() - */ -#define io_wait_event(wq, condition) \ -do { \ - might_sleep(); \ - if (condition) \ - break; \ - __io_wait_event(wq, condition); \ -} while (0) - -#define __wait_event_freezable(wq, condition) \ - ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \ - schedule(); try_to_freeze()) - -/** - * wait_event_freezable - sleep (or freeze) 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 -- so as not to contribute - * to system load) until the @condition evaluates to true. The - * @condition is checked each time the waitqueue @wq is woken up. - * - * wake_up() has to be called after changing any variable that could - * change the result of the wait condition. - */ -#define wait_event_freezable(wq, condition) \ -({ \ - int __ret = 0; \ - might_sleep(); \ - if (!(condition)) \ - __ret = __wait_event_freezable(wq, condition); \ - __ret; \ -}) - #define __wait_event_timeout(wq, condition, timeout) \ ___wait_event(wq, ___wait_cond_timeout(condition), \ TASK_UNINTERRUPTIBLE, 0, timeout, \ __ret = schedule_timeout(__ret)) -/** - * wait_event_timeout - sleep until a condition gets true or a timeout elapses - * @wq: the waitqueue to wait on - * @condition: a C expression for the event to wait for - * @timeout: timeout, in jiffies - * - * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the - * @condition evaluates to true. The @condition is checked each time - * the waitqueue @wq is woken up. - * - * wake_up() has to be called after changing any variable that could - * change the result of the wait condition. - * - * Returns: - * 0 if the @condition evaluated to %false after the @timeout elapsed, - * 1 if the @condition evaluated to %true after the @timeout elapsed, - * or the remaining jiffies (at least 1) if the @condition evaluated - * to %true before the @timeout elapsed. - */ #define wait_event_timeout(wq, condition, timeout) \ ({ \ long __ret = timeout; \ - might_sleep(); \ if (!___wait_cond_timeout(condition)) \ __ret = __wait_event_timeout(wq, condition, timeout); \ __ret; \ }) -#define __wait_event_freezable_timeout(wq, condition, timeout) \ - ___wait_event(wq, ___wait_cond_timeout(condition), \ - TASK_INTERRUPTIBLE, 0, timeout, \ - __ret = schedule_timeout(__ret); try_to_freeze()) - -/* - * like wait_event_timeout() -- except it uses TASK_INTERRUPTIBLE to avoid - * increasing load and is freezable. - */ -#define wait_event_freezable_timeout(wq, condition, timeout) \ -({ \ - long __ret = timeout; \ - might_sleep(); \ - if (!___wait_cond_timeout(condition)) \ - __ret = __wait_event_freezable_timeout(wq, condition, timeout); \ - __ret; \ -}) - -#define __wait_event_exclusive_cmd(wq, condition, cmd1, cmd2) \ - (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 1, 0, \ - cmd1; schedule(); cmd2) -/* - * Just like wait_event_cmd(), except it sets exclusive flag - */ -#define wait_event_exclusive_cmd(wq, condition, cmd1, cmd2) \ -do { \ - if (condition) \ - break; \ - __wait_event_exclusive_cmd(wq, condition, cmd1, cmd2); \ -} while (0) - -#define __wait_event_cmd(wq, condition, cmd1, cmd2) \ - (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ - cmd1; schedule(); cmd2) - -/** - * wait_event_cmd - sleep until a condition gets true - * @wq: the waitqueue to wait on - * @condition: a C expression for the event to wait for - * @cmd1: the command will be executed before sleep - * @cmd2: the command will be executed after sleep - * - * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the - * @condition evaluates to true. The @condition is checked each time - * the waitqueue @wq is woken up. - * - * wake_up() has to be called after changing any variable that could - * change the result of the wait condition. - */ -#define wait_event_cmd(wq, condition, cmd1, cmd2) \ -do { \ - if (condition) \ - break; \ - __wait_event_cmd(wq, condition, cmd1, cmd2); \ -} while (0) - -#define __wait_event_interruptible(wq, condition) \ - ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \ - schedule()) - -/** - * wait_event_interruptible - 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. - * - * wake_up() 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(wq, condition) \ -({ \ - int __ret = 0; \ - might_sleep(); \ - if (!(condition)) \ - __ret = __wait_event_interruptible(wq, condition); \ - __ret; \ -}) - -#define __wait_event_interruptible_timeout(wq, condition, timeout) \ - ___wait_event(wq, ___wait_cond_timeout(condition), \ - TASK_INTERRUPTIBLE, 0, timeout, \ - __ret = schedule_timeout(__ret)) - -/** - * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses - * @wq: the waitqueue to wait on - * @condition: a C expression for the event to wait for - * @timeout: timeout, in jiffies - * - * 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. - * - * wake_up() has to be called after changing any variable that could - * change the result of the wait condition. - * - * Returns: - * 0 if the @condition evaluated to %false after the @timeout elapsed, - * 1 if the @condition evaluated to %true after the @timeout elapsed, - * the remaining jiffies (at least 1) if the @condition evaluated - * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was - * interrupted by a signal. - */ -#define wait_event_interruptible_timeout(wq, condition, timeout) \ -({ \ - long __ret = timeout; \ - might_sleep(); \ - if (!___wait_cond_timeout(condition)) \ - __ret = __wait_event_interruptible_timeout(wq, \ - condition, timeout); \ - __ret; \ -}) - -#define __wait_event_hrtimeout(wq, condition, timeout, state) \ -({ \ - int __ret = 0; \ - struct hrtimer_sleeper __t; \ - \ - hrtimer_init_on_stack(&__t.timer, CLOCK_MONOTONIC, \ - HRTIMER_MODE_REL); \ - hrtimer_init_sleeper(&__t, current); \ - if ((timeout).tv64 != KTIME_MAX) \ - hrtimer_start_range_ns(&__t.timer, timeout, \ - current->timer_slack_ns, \ - HRTIMER_MODE_REL); \ - \ - __ret = ___wait_event(wq, condition, state, 0, 0, \ - if (!__t.task) { \ - __ret = -ETIME; \ - break; \ - } \ - schedule()); \ - \ - hrtimer_cancel(&__t.timer); \ - destroy_hrtimer_on_stack(&__t.timer); \ - __ret; \ -}) - -/** - * wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses - * @wq: the waitqueue to wait on - * @condition: a C expression for the event to wait for - * @timeout: timeout, as a ktime_t - * - * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the - * @condition evaluates to true or a signal is received. - * The @condition is checked each time the waitqueue @wq is woken up. - * - * wake_up() has to be called after changing any variable that could - * change the result of the wait condition. - * - * The function returns 0 if @condition became true, or -ETIME if the timeout - * elapsed. - */ -#define wait_event_hrtimeout(wq, condition, timeout) \ -({ \ - int __ret = 0; \ - might_sleep(); \ - if (!(condition)) \ - __ret = __wait_event_hrtimeout(wq, condition, timeout, \ - TASK_UNINTERRUPTIBLE); \ - __ret; \ -}) - -/** - * wait_event_interruptible_hrtimeout - sleep until a condition gets true or a timeout elapses - * @wq: the waitqueue to wait on - * @condition: a C expression for the event to wait for - * @timeout: timeout, as a ktime_t - * - * 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. - * - * wake_up() has to be called after changing any variable that could - * change the result of the wait condition. - * - * The function returns 0 if @condition became true, -ERESTARTSYS if it was - * interrupted by a signal, or -ETIME if the timeout elapsed. - */ -#define wait_event_interruptible_hrtimeout(wq, condition, timeout) \ -({ \ - long __ret = 0; \ - might_sleep(); \ - if (!(condition)) \ - __ret = __wait_event_hrtimeout(wq, condition, timeout, \ - TASK_INTERRUPTIBLE); \ - __ret; \ -}) - -#define __wait_event_interruptible_exclusive(wq, condition) \ - ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \ - schedule()) - -#define wait_event_interruptible_exclusive(wq, condition) \ -({ \ - int __ret = 0; \ - might_sleep(); \ - if (!(condition)) \ - __ret = __wait_event_interruptible_exclusive(wq, condition);\ - __ret; \ -}) - -#define __wait_event_killable_exclusive(wq, condition) \ - ___wait_event(wq, condition, TASK_KILLABLE, 1, 0, \ - schedule()) - -#define wait_event_killable_exclusive(wq, condition) \ -({ \ - int __ret = 0; \ - might_sleep(); \ - if (!(condition)) \ - __ret = __wait_event_killable_exclusive(wq, condition); \ - __ret; \ -}) - - -#define __wait_event_freezable_exclusive(wq, condition) \ - ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0, \ - schedule(); try_to_freeze()) - -#define wait_event_freezable_exclusive(wq, condition) \ -({ \ - int __ret = 0; \ - might_sleep(); \ - if (!(condition)) \ - __ret = __wait_event_freezable_exclusive(wq, condition);\ - __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) \ - ___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule()) - -/** - * wait_event_killable - 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_KILLABLE) until the - * @condition evaluates to true or a signal is received. - * The @condition is checked each time the waitqueue @wq is woken up. - * - * wake_up() 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_killable(wq, condition) \ -({ \ - int __ret = 0; \ - might_sleep(); \ - if (!(condition)) \ - __ret = __wait_event_killable(wq, condition); \ - __ret; \ -}) - - -#define __wait_event_lock_irq(wq, condition, lock, cmd) \ - (void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0, \ - spin_unlock_irq(&lock); \ - cmd; \ - schedule(); \ - spin_lock_irq(&lock)) - -/** - * wait_event_lock_irq_cmd - sleep until a condition gets true. The - * condition is checked under the lock. This - * is expected to be called with the lock - * taken. - * @wq: the waitqueue to wait on - * @condition: a C expression for the event to wait for - * @lock: a locked spinlock_t, which will be released before cmd - * and schedule() and reacquired afterwards. - * @cmd: a command which is invoked outside the critical section before - * sleep - * - * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the - * @condition evaluates to true. The @condition is checked each time - * the waitqueue @wq is woken up. - * - * wake_up() has to be called after changing any variable that could - * change the result of the wait condition. - * - * This is supposed to be called while holding the lock. The lock is - * dropped before invoking the cmd and going to sleep and is reacquired - * afterwards. - */ -#define wait_event_lock_irq_cmd(wq, condition, lock, cmd) \ -do { \ - if (condition) \ - break; \ - __wait_event_lock_irq(wq, condition, lock, cmd); \ -} while (0) - -/** - * wait_event_lock_irq - sleep until a condition gets true. The - * condition is checked under the lock. This - * is expected to be called with the lock - * taken. - * @wq: the waitqueue to wait on - * @condition: a C expression for the event to wait for - * @lock: a locked spinlock_t, which will be released before schedule() - * and reacquired afterwards. - * - * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the - * @condition evaluates to true. The @condition is checked each time - * the waitqueue @wq is woken up. - * - * wake_up() has to be called after changing any variable that could - * change the result of the wait condition. - * - * This is supposed to be called while holding the lock. The lock is - * dropped before going to sleep and is reacquired afterwards. - */ -#define wait_event_lock_irq(wq, condition, lock) \ -do { \ - if (condition) \ - break; \ - __wait_event_lock_irq(wq, condition, lock, ); \ -} while (0) - - -#define __wait_event_interruptible_lock_irq(wq, condition, lock, cmd) \ - ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 0, 0, \ - spin_unlock_irq(&lock); \ - cmd; \ - schedule(); \ - spin_lock_irq(&lock)) - -/** - * wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true. - * The condition is checked under the lock. This is expected to - * be called with the lock taken. - * @wq: the waitqueue to wait on - * @condition: a C expression for the event to wait for - * @lock: a locked spinlock_t, which will be released before cmd and - * schedule() and reacquired afterwards. - * @cmd: a command which is invoked outside the critical section before - * sleep - * - * 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. - * - * wake_up() has to be called after changing any variable that could - * change the result of the wait condition. - * - * This is supposed to be called while holding the lock. The lock is - * dropped before invoking the cmd and going to sleep and is reacquired - * afterwards. - * - * The macro will return -ERESTARTSYS if it was interrupted by a signal - * and 0 if @condition evaluated to true. - */ -#define wait_event_interruptible_lock_irq_cmd(wq, condition, lock, cmd) \ -({ \ - int __ret = 0; \ - if (!(condition)) \ - __ret = __wait_event_interruptible_lock_irq(wq, \ - condition, lock, cmd); \ - __ret; \ -}) - -/** - * wait_event_interruptible_lock_irq - sleep until a condition gets true. - * The condition is checked under the lock. This is expected - * to be called with the lock taken. - * @wq: the waitqueue to wait on - * @condition: a C expression for the event to wait for - * @lock: a locked spinlock_t, which will be released before schedule() - * and reacquired afterwards. - * - * The process is put to sleep (TASK_INTERRUPTIBLE) until the - * @condition evaluates to true or signal is received. The @condition is - * checked each time the waitqueue @wq is woken up. - * - * wake_up() has to be called after changing any variable that could - * change the result of the wait condition. - * - * This is supposed to be called while holding the lock. The lock is - * dropped before going to sleep and is reacquired afterwards. - * - * The macro will return -ERESTARTSYS if it was interrupted by a signal - * and 0 if @condition evaluated to true. - */ -#define wait_event_interruptible_lock_irq(wq, condition, lock) \ -({ \ - int __ret = 0; \ - if (!(condition)) \ - __ret = __wait_event_interruptible_lock_irq(wq, \ - condition, lock,); \ - __ret; \ -}) - -#define __wait_event_interruptible_lock_irq_timeout(wq, condition, \ - lock, timeout) \ - ___wait_event(wq, ___wait_cond_timeout(condition), \ - TASK_INTERRUPTIBLE, 0, timeout, \ - spin_unlock_irq(&lock); \ - __ret = schedule_timeout(__ret); \ - spin_lock_irq(&lock)); - -/** - * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets - * true or a timeout elapses. The condition is checked under - * the lock. This is expected to be called with the lock taken. - * @wq: the waitqueue to wait on - * @condition: a C expression for the event to wait for - * @lock: a locked spinlock_t, which will be released before schedule() - * and reacquired afterwards. - * @timeout: timeout, in jiffies - * - * The process is put to sleep (TASK_INTERRUPTIBLE) until the - * @condition evaluates to true or signal is received. The @condition is - * checked each time the waitqueue @wq is woken up. - * - * wake_up() has to be called after changing any variable that could - * change the result of the wait condition. - * - * This is supposed to be called while holding the lock. The lock is - * dropped before going to sleep and is reacquired afterwards. - * - * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it - * was interrupted by a signal, and the remaining jiffies otherwise - * if the condition evaluated to true before the timeout elapsed. - */ -#define wait_event_interruptible_lock_irq_timeout(wq, condition, lock, \ - timeout) \ -({ \ - long __ret = timeout; \ - if (!___wait_cond_timeout(condition)) \ - __ret = __wait_event_interruptible_lock_irq_timeout( \ - wq, condition, lock, timeout); \ - __ret; \ -}) - -/* - * Waitqueues which are removed from the waitqueue_head at wakeup time - */ -void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state); -void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state); -long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state); -void finish_wait(wait_queue_head_t *q, wait_queue_t *wait); -void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait, unsigned int mode, void *key); -long wait_woken(wait_queue_t *wait, unsigned mode, long timeout); -int woken_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); -int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); -int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key); - -#define DEFINE_WAIT_FUNC(name, function) \ - wait_queue_t name = { \ - .private = current, \ - .func = function, \ - .task_list = LIST_HEAD_INIT((name).task_list), \ - } - -#define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function) - -#define DEFINE_WAIT_BIT(name, word, bit) \ - struct wait_bit_queue name = { \ - .key = __WAIT_BIT_KEY_INITIALIZER(word, bit), \ - .wait = { \ - .private = current, \ - .func = wake_bit_function, \ - .task_list = \ - LIST_HEAD_INIT((name).wait.task_list), \ - }, \ - } - -#define init_wait(wait) \ - do { \ - (wait)->private = current; \ - (wait)->func = autoremove_wake_function; \ - INIT_LIST_HEAD(&(wait)->task_list); \ - (wait)->flags = 0; \ - } while (0) - - -extern int bit_wait(struct wait_bit_key *, int); -extern int bit_wait_io(struct wait_bit_key *, int); -extern int bit_wait_timeout(struct wait_bit_key *, int); -extern int bit_wait_io_timeout(struct wait_bit_key *, int); +void wake_up_bit(void *, int); +void __wait_on_bit(void *, int, unsigned); +void __wait_on_bit_lock(void *, int, unsigned); -/** - * wait_on_bit - wait for a bit to be cleared - * @word: the word being waited on, a kernel virtual address - * @bit: the bit of the word being waited on - * @mode: the task state to sleep in - * - * There is a standard hashed waitqueue table for generic use. This - * is the part of the hashtable's accessor API that waits on a bit. - * For instance, if one were to have waiters on a bitflag, one would - * call wait_on_bit() in threads waiting for the bit to clear. - * One uses wait_on_bit() where one is waiting for the bit to clear, - * but has no intention of setting it. - * Returned value will be zero if the bit was cleared, or non-zero - * if the process received a signal and the mode permitted wakeup - * on that signal. - */ static inline int wait_on_bit(unsigned long *word, int bit, unsigned mode) { - might_sleep(); if (!test_bit(bit, word)) return 0; - return out_of_line_wait_on_bit(word, bit, - bit_wait, - mode); + __wait_on_bit(word, bit, mode); + return 0; } -/** - * wait_on_bit_io - wait for a bit to be cleared - * @word: the word being waited on, a kernel virtual address - * @bit: the bit of the word being waited on - * @mode: the task state to sleep in - * - * Use the standard hashed waitqueue table to wait for a bit - * to be cleared. This is similar to wait_on_bit(), but calls - * io_schedule() instead of schedule() for the actual waiting. - * - * Returned value will be zero if the bit was cleared, or non-zero - * if the process received a signal and the mode permitted wakeup - * on that signal. - */ -static inline int -wait_on_bit_io(unsigned long *word, int bit, unsigned mode) -{ - might_sleep(); - if (!test_bit(bit, word)) - return 0; - return out_of_line_wait_on_bit(word, bit, - bit_wait_io, - mode); -} - -/** - * wait_on_bit_timeout - wait for a bit to be cleared or a timeout elapses - * @word: the word being waited on, a kernel virtual address - * @bit: the bit of the word being waited on - * @mode: the task state to sleep in - * @timeout: timeout, in jiffies - * - * Use the standard hashed waitqueue table to wait for a bit - * to be cleared. This is similar to wait_on_bit(), except also takes a - * timeout parameter. - * - * Returned value will be zero if the bit was cleared before the - * @timeout elapsed, or non-zero if the @timeout elapsed or process - * received a signal and the mode permitted wakeup on that signal. - */ -static inline int -wait_on_bit_timeout(unsigned long *word, int bit, unsigned mode, - unsigned long timeout) -{ - might_sleep(); - if (!test_bit(bit, word)) - return 0; - return out_of_line_wait_on_bit_timeout(word, bit, - bit_wait_timeout, - mode, timeout); -} - -/** - * wait_on_bit_action - wait for a bit to be cleared - * @word: the word being waited on, a kernel virtual address - * @bit: the bit of the word being waited on - * @action: the function used to sleep, which may take special actions - * @mode: the task state to sleep in - * - * Use the standard hashed waitqueue table to wait for a bit - * to be cleared, and allow the waiting action to be specified. - * This is like wait_on_bit() but allows fine control of how the waiting - * is done. - * - * Returned value will be zero if the bit was cleared, or non-zero - * if the process received a signal and the mode permitted wakeup - * on that signal. - */ -static inline int -wait_on_bit_action(unsigned long *word, int bit, wait_bit_action_f *action, - unsigned mode) -{ - might_sleep(); - if (!test_bit(bit, word)) - return 0; - return out_of_line_wait_on_bit(word, bit, action, mode); -} - -/** - * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it - * @word: the word being waited on, a kernel virtual address - * @bit: the bit of the word being waited on - * @mode: the task state to sleep in - * - * There is a standard hashed waitqueue table for generic use. This - * is the part of the hashtable's accessor API that waits on a bit - * when one intends to set it, for instance, trying to lock bitflags. - * For instance, if one were to have waiters trying to set bitflag - * and waiting for it to clear before setting it, one would call - * wait_on_bit() in threads waiting to be able to set the bit. - * One uses wait_on_bit_lock() where one is waiting for the bit to - * clear with the intention of setting it, and when done, clearing it. - * - * Returns zero if the bit was (eventually) found to be clear and was - * set. Returns non-zero if a signal was delivered to the process and - * the @mode allows that signal to wake the process. - */ static inline int wait_on_bit_lock(unsigned long *word, int bit, unsigned mode) { - might_sleep(); if (!test_and_set_bit(bit, word)) return 0; - return out_of_line_wait_on_bit_lock(word, bit, bit_wait, mode); + __wait_on_bit_lock(word, bit, mode); + return 0; } -/** - * wait_on_bit_lock_io - wait for a bit to be cleared, when wanting to set it - * @word: the word being waited on, a kernel virtual address - * @bit: the bit of the word being waited on - * @mode: the task state to sleep in - * - * Use the standard hashed waitqueue table to wait for a bit - * to be cleared and then to atomically set it. This is similar - * to wait_on_bit(), but calls io_schedule() instead of schedule() - * for the actual waiting. - * - * Returns zero if the bit was (eventually) found to be clear and was - * set. Returns non-zero if a signal was delivered to the process and - * the @mode allows that signal to wake the process. - */ -static inline int -wait_on_bit_lock_io(unsigned long *word, int bit, unsigned mode) -{ - might_sleep(); - if (!test_and_set_bit(bit, word)) - return 0; - return out_of_line_wait_on_bit_lock(word, bit, bit_wait_io, mode); -} - -/** - * wait_on_bit_lock_action - wait for a bit to be cleared, when wanting to set it - * @word: the word being waited on, a kernel virtual address - * @bit: the bit of the word being waited on - * @action: the function used to sleep, which may take special actions - * @mode: the task state to sleep in - * - * Use the standard hashed waitqueue table to wait for a bit - * to be cleared and then to set it, and allow the waiting action - * to be specified. - * This is like wait_on_bit() but allows fine control of how the waiting - * is done. - * - * Returns zero if the bit was (eventually) found to be clear and was - * set. Returns non-zero if a signal was delivered to the process and - * the @mode allows that signal to wake the process. - */ -static inline int -wait_on_bit_lock_action(unsigned long *word, int bit, wait_bit_action_f *action, - unsigned mode) -{ - might_sleep(); - if (!test_and_set_bit(bit, word)) - return 0; - return out_of_line_wait_on_bit_lock(word, bit, action, mode); -} - -/** - * wait_on_atomic_t - Wait for an atomic_t to become 0 - * @val: The atomic value being waited on, a kernel virtual address - * @action: the function used to sleep, which may take special actions - * @mode: the task state to sleep in - * - * Wait for an atomic_t to become 0. We abuse the bit-wait waitqueue table for - * the purpose of getting a waitqueue, but we set the key to a bit number - * outside of the target 'word'. - */ -static inline -int wait_on_atomic_t(atomic_t *val, int (*action)(atomic_t *), unsigned mode) -{ - might_sleep(); - if (atomic_read(val) == 0) - return 0; - return out_of_line_wait_on_atomic_t(val, action, mode); -} +#define wait_on_bit_io(w, b, m) wait_on_bit(w, b, m) +#define wait_on_bit_lock_io(w, b, m) wait_on_bit_lock(w, b, m) #endif /* _LINUX_WAIT_H */ |