/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_WAIT_H#define _LINUX_WAIT_H/* * Linux wait queue related types and methods #include <linux/list.h>#include <linux/stddef.h>#include <linux/spinlock.h>#include <asm /current.h>typedef struct wait_queue_entry wait_queue_entry_t;typedef int (*wait_queue_func_t)(struct wait_queue_entry *wq_entry, unsigned mode, int flags, void *key);int default_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int flags, void *key);/* wait_queue_entry::flags */ #define WQ_FLAG_EXCLUSIVE 0 x01#define WQ_FLAG_WOKEN 0 x02#define WQ_FLAG_CUSTOM 0 x04#define WQ_FLAG_DONE 0 x08#define WQ_FLAG_PRIORITY 0 x10/* * A single wait - queue entry structure : struct wait_queue_entry {unsigned int flags;void *private ;struct list_head entry;struct wait_queue_head {struct list_head head;typedef struct wait_queue_head wait_queue_head_t;struct task_struct;/* * Macros for declaration and initialisaton of the datatypes #define __WAITQUEUE_INITIALIZER(name, tsk) { \private = tsk, \#define DECLARE_WAITQUEUE(name, tsk) \struct wait_queue_entry name = __WAITQUEUE_INITIALIZER(name, tsk)#define __WAIT_QUEUE_HEAD_INITIALIZER(name) { \#define DECLARE_WAIT_QUEUE_HEAD(name) \struct wait_queue_head name = __WAIT_QUEUE_HEAD_INITIALIZER(name)extern void __init_waitqueue_head(struct wait_queue_head *wq_head, const char *name, struct lock_class_key *);#define init_waitqueue_head(wq_head) \do { \static struct lock_class_key __key; \#wq_head , &__key); \while (0 )#ifdef CONFIG_LOCKDEP# define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \struct wait_queue_head 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(struct wait_queue_entry *wq_entry, struct task_struct *p)0 ;private = p;static inline void struct wait_queue_entry *wq_entry, wait_queue_func_t func)0 ;private = NULL;/** * waitqueue_active - - locklessly test for waiters on the queue * @ wq_head : 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 : : lock or when used for wakeups * with an extra smp_mb ( ) like : : * * CPU0 - waker CPU1 - waiter * * for ( ; ; ) { * @ cond = true ; prepare_to_wait ( & wq_head , & wait , state ) ; * smp_mb ( ) ; // smp_mb() from set_current_state() * if ( waitqueue_active ( wq_head ) ) if ( @ cond ) * wake_up ( wq_head ) ; break ; * schedule ( ) ; * } * finish_wait ( & wq_head , & 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(struct wait_queue_head *wq_head)return !list_empty(&wq_head->head);/** * wq_has_single_sleeper - check if there is only one sleeper * @ wq_head : wait queue head * * Returns true of wq_head has only one sleeper on the list . * * Please refer to the comment for waitqueue_active . static inline bool wq_has_single_sleeper(struct wait_queue_head *wq_head)return list_is_singular(&wq_head->head);/** * wq_has_sleeper - check if there are any waiting processes * @ wq_head : wait queue head * * Returns true if wq_head has waiting processes * * Please refer to the comment for waitqueue_active . static inline bool wq_has_sleeper(struct wait_queue_head *wq_head)/* * 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 . return waitqueue_active(wq_head);extern void add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);extern void add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);extern void add_wait_queue_priority(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);extern int add_wait_queue_priority_exclusive(struct wait_queue_head *wq_head,struct wait_queue_entry *wq_entry);extern void remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);static inline void __add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)struct list_head *head = &wq_head->head;struct wait_queue_entry *wq;if (!(wq->flags & WQ_FLAG_PRIORITY))break ;/* * Used for wake - one threads : static inline void struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)static inline void __add_wait_queue_entry_tail(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)static inline void struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)static inline void struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)int __wake_up(struct wait_queue_head *wq_head, unsigned int mode, int nr, void *key);void __wake_up_on_current_cpu(struct wait_queue_head *wq_head, unsigned int mode, void *key);void __wake_up_locked_key(struct wait_queue_head *wq_head, unsigned int mode, void *key);void __wake_up_sync_key(struct wait_queue_head *wq_head, unsigned int mode, void *key);void __wake_up_locked_sync_key(struct wait_queue_head *wq_head, unsigned int mode, void *key);void __wake_up_locked(struct wait_queue_head *wq_head, unsigned int mode, int nr);void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode);void __wake_up_pollfree(struct wait_queue_head *wq_head);#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_sync(x) __wake_up_sync(x, TASK_NORMAL)#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)/* * Wakeup macros to be used to report events to the targets . #define poll_to_key(m) ((void *)(__force uintptr_t)(__poll_t)(m))#define key_to_poll(m) ((__force __poll_t)(uintptr_t)(void *)(m))#define wake_up_poll(x, m) \1 , poll_to_key(m))#define wake_up_poll_on_current_cpu(x, m) \#define wake_up_locked_poll(x, m) \#define wake_up_interruptible_poll(x, m) \1 , poll_to_key(m))#define wake_up_interruptible_sync_poll(x, m) \#define wake_up_interruptible_sync_poll_locked(x, m) \/** * wake_up_pollfree - signal that a polled waitqueue is going away * @ wq_head : the wait queue head * * In the very rare cases where a - > poll ( ) implementation uses a waitqueue whose * lifetime is tied to a task rather than to the ' struct file ' being polled , * this function must be called before the waitqueue is freed so that * non - blocking polls ( e . g . epoll ) are notified that the queue is going away . * * The caller must also RCU - delay the freeing of the wait_queue_head , e . g . via * an explicit synchronize_rcu ( ) or call_rcu ( ) , or via SLAB_TYPESAFE_BY_RCU . static inline void wake_up_pollfree(struct wait_queue_head *wq_head)/* * For performance reasons , we don ' t always take the queue lock here . * Therefore , we might race with someone removing the last entry from * the queue , and proceed while they still hold the queue lock . * However , rcu_read_lock ( ) is required to be held in such cases , so we * can safely proceed with an RCU - delayed free . if (waitqueue_active(wq_head))#define ___wait_cond_timeout(condition) \bool __cond = (condition); \if (__cond && !__ret) \1 ; \#define ___wait_is_interruptible(state) \extern void init_wait_entry(struct wait_queue_entry *wq_entry, int flags);/* * 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_head, condition, state, exclusive, ret, cmd) \struct wait_queue_entry __wq_entry; \long __ret = ret; /* explicit shadow */ \ 0 ); \for (;;) { \long __int = prepare_to_wait_event(&wq_head, &__wq_entry, state);\if (condition) \break ; \if (___wait_is_interruptible(state) && __int ) { \int ; \goto __out; \if (condition) \break ; \#define __wait_event(wq_head, condition) \void )___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0 , 0 , \/** * wait_event - sleep until a condition gets true * @ wq_head : 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_head 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_head, condition) \do { \if (condition) \break ; \while (0 )#define __io_wait_event(wq_head, condition) \void )___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0 , 0 , \/* * io_wait_event ( ) - - like wait_event ( ) but with io_schedule ( ) #define io_wait_event(wq_head, condition) \do { \if (condition) \break ; \while (0 )#define __wait_event_freezable(wq_head, condition) \0 , 0 , schedule())/** * wait_event_freezable - sleep ( or freeze ) until a condition gets true * @ wq_head : 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_head 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_head, condition) \int __ret = 0 ; \if (!(condition)) \#define __wait_event_timeout(wq_head, condition, timeout) \0 , timeout, \/** * wait_event_timeout - sleep until a condition gets true or a timeout elapses * @ wq_head : 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_head 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_head, condition, timeout) \long __ret = timeout; \if (!___wait_cond_timeout(condition)) \#define __wait_event_freezable_timeout(wq_head, condition, timeout) \0 , timeout, \/* * like wait_event_timeout ( ) - - except it uses TASK_INTERRUPTIBLE to avoid * increasing load and is freezable . #define wait_event_freezable_timeout(wq_head, condition, timeout) \long __ret = timeout; \if (!___wait_cond_timeout(condition)) \#define __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2) \void )___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 1 , 0 , \/* * Just like wait_event_cmd ( ) , except it sets exclusive flag #define wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2) \do { \if (condition) \break ; \while (0 )#define __wait_event_cmd(wq_head, condition, cmd1, cmd2) \void )___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0 , 0 , \/** * wait_event_cmd - sleep until a condition gets true * @ wq_head : 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_head 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_head, condition, cmd1, cmd2) \do { \if (condition) \break ; \while (0 )#define __wait_event_interruptible(wq_head, condition) \0 , 0 , \/** * wait_event_interruptible - sleep until a condition gets true * @ wq_head : 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_head 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_head, condition) \int __ret = 0 ; \if (!(condition)) \#define __wait_event_interruptible_timeout(wq_head, condition, timeout) \0 , timeout, \/** * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses * @ wq_head : 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_head 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_head, condition, timeout) \long __ret = timeout; \if (!___wait_cond_timeout(condition)) \#define __wait_event_hrtimeout(wq_head, condition, timeout, state) \int __ret = 0 ; \struct hrtimer_sleeper __t; \if ((timeout) != KTIME_MAX) { \0 , 0 , \if (!__t.task) { \break ; \/** * wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses * @ wq_head : 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_head 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_head, condition, timeout) \int __ret = 0 ; \if (!(condition)) \/** * 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 ; \if (!(condition)) \#define __wait_event_interruptible_exclusive(wq, condition) \1 , 0 , \#define wait_event_interruptible_exclusive(wq, condition) \int __ret = 0 ; \if (!(condition)) \#define __wait_event_killable_exclusive(wq, condition) \1 , 0 , \#define wait_event_killable_exclusive(wq, condition) \int __ret = 0 ; \if (!(condition)) \#define __wait_event_freezable_exclusive(wq, condition) \1 , 0 ,\#define wait_event_freezable_exclusive(wq, condition) \int __ret = 0 ; \if (!(condition)) \/** * wait_event_idle - wait for a condition without contributing to system load * @ wq_head : the waitqueue to wait on * @ condition : a C expression for the event to wait for * * The process is put to sleep ( TASK_IDLE ) until the * @ condition evaluates to true . * The @ condition is checked each time the waitqueue @ wq_head 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_idle(wq_head, condition) \do { \if (!(condition)) \0 , 0 , schedule()); \while (0 )/** * wait_event_idle_exclusive - wait for a condition with contributing to system load * @ wq_head : the waitqueue to wait on * @ condition : a C expression for the event to wait for * * The process is put to sleep ( TASK_IDLE ) until the * @ condition evaluates to true . * The @ condition is checked each time the waitqueue @ wq_head is woken up . * * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag * set thus if other processes wait on the same list , when this * process is woken further processes are not considered . * * wake_up ( ) has to be called after changing any variable that could * change the result of the wait condition . * #define wait_event_idle_exclusive(wq_head, condition) \do { \if (!(condition)) \1 , 0 , schedule()); \while (0 )#define __wait_event_idle_timeout(wq_head, condition, timeout) \0 , timeout, \/** * wait_event_idle_timeout - sleep without load until a condition becomes true or a timeout elapses * @ wq_head : 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_IDLE ) until the * @ condition evaluates to true . The @ condition is checked each time * the waitqueue @ wq_head 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_idle_timeout(wq_head, condition, timeout) \long __ret = timeout; \if (!___wait_cond_timeout(condition)) \#define __wait_event_idle_exclusive_timeout(wq_head, condition, timeout) \1 , timeout, \/** * wait_event_idle_exclusive_timeout - sleep without load until a condition becomes true or a timeout elapses * @ wq_head : 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_IDLE ) until the * @ condition evaluates to true . The @ condition is checked each time * the waitqueue @ wq_head is woken up . * * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag * set thus if other processes wait on the same list , when this * process is woken further processes are not considered . * * 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_idle_exclusive_timeout(wq_head, condition, timeout) \long __ret = timeout; \if (!___wait_cond_timeout(condition)) \extern int do_wait_intr(wait_queue_head_t *, wait_queue_entry_t *);extern int do_wait_intr_irq(wait_queue_head_t *, wait_queue_entry_t *);#define __wait_event_interruptible_locked(wq, condition, exclusive, fn) \int __ret; \if (exclusive) \do { \if (__ret) \break ; \while (!(condition)); \/** * 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) \0 : __wait_event_interruptible_locked(wq, condition, 0 , do_wait_intr))/** * 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) \0 : __wait_event_interruptible_locked(wq, condition, 0 , do_wait_intr_irq))/** * 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) \0 : __wait_event_interruptible_locked(wq, condition, 1 , do_wait_intr))/** * 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) \0 : __wait_event_interruptible_locked(wq, condition, 1 , do_wait_intr_irq))#define __wait_event_killable(wq, condition) \0 , 0 , schedule())/** * wait_event_killable - sleep until a condition gets true * @ wq_head : 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_head 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_head, condition) \int __ret = 0 ; \if (!(condition)) \#define __wait_event_state(wq, condition, state) \0 , 0 , schedule())/** * wait_event_state - sleep until a condition gets true * @ wq_head : the waitqueue to wait on * @ condition : a C expression for the event to wait for * @ state : state to sleep in * * The process is put to sleep ( @ state ) until the @ condition evaluates to true * or a signal is received ( when allowed by @ state ) . The @ condition is checked * each time the waitqueue @ wq_head 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 * ( when allowed by @ state ) and 0 if @ condition evaluated to true . #define wait_event_state(wq_head, condition, state) \int __ret = 0 ; \if (!(condition)) \#define __wait_event_killable_timeout(wq_head, condition, timeout) \0 , timeout, \/** * wait_event_killable_timeout - sleep until a condition gets true or a timeout elapses * @ wq_head : 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_KILLABLE ) until the * @ condition evaluates to true or a kill signal is received . * The @ condition is checked each time the waitqueue @ wq_head 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 kill signal . * * Only kill signals interrupt this process . #define wait_event_killable_timeout(wq_head, condition, timeout) \long __ret = timeout; \if (!___wait_cond_timeout(condition)) \#define __wait_event_lock_irq(wq_head, condition, lock, cmd) \void )___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0 , 0 , \/** * 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_head : 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_head 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_head, condition, lock, cmd) \do { \if (condition) \break ; \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_head : 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_head 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_head, condition, lock) \do { \if (condition) \break ; \while (0 )#define __wait_event_interruptible_lock_irq(wq_head, condition, lock, cmd) \0 , 0 , \/** * 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_head : 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_head 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_head, condition, lock, cmd) \int __ret = 0 ; \if (!(condition)) \/** * 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_head : 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_head 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_head, condition, lock) \int __ret = 0 ; \if (!(condition)) \#define __wait_event_lock_irq_timeout(wq_head, condition, lock, timeout, state) \0 , timeout, \/** * 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_head : 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_head 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_head, condition, lock, \long __ret = timeout; \if (!___wait_cond_timeout(condition)) \#define wait_event_lock_irq_timeout(wq_head, condition, lock, timeout) \long __ret = timeout; \if (!___wait_cond_timeout(condition)) \/* * Waitqueues which are removed from the waitqueue_head at wakeup time void prepare_to_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);bool prepare_to_wait_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);long prepare_to_wait_event(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);void finish_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);long wait_woken(struct wait_queue_entry *wq_entry, unsigned mode, long timeout);int woken_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key);int autoremove_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key);#define DEFINE_WAIT_FUNC(name, function) \struct wait_queue_entry name = { \private = current, \#define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function)#define init_wait_func(wait, function) \do { \private = current; \0 ; \while (0 )#define init_wait(wait) init_wait_func(wait, autoremove_wake_function)typedef int (*task_call_f)(struct task_struct *p, void *arg);extern int task_call_func(struct task_struct *p, task_call_f func, void *arg);#endif /* _LINUX_WAIT_H */
Messung V0.5 in Prozent C=97 H=84 G=90
¤ Dauer der Verarbeitung: 0.50 Sekunden
(vorverarbeitet am 2026-09-29)
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