#ifndef _LINUX_WAIT_H #define _LINUX_WAIT_H #define WNOHANG 0x00000001 #define WUNTRACED 0x00000002 #define WSTOPPED WUNTRACED #define WEXITED 0x00000004 #define WCONTINUED 0x00000008 #define WNOWAIT 0x01000000 /* Don't reap, just poll status. */ #define __WNOTHREAD 0x20000000 /* Don't wait on children of other threads in this group */ #define __WALL 0x40000000 /* Wait on all children, regardless of type */ #define __WCLONE 0x80000000 /* Wait only on non-SIGCHLD children */ /* First argument to waitid: */ #define P_ALL 0 #define P_PID 1 #define P_PGID 2 #ifdef __KERNEL__ #include <linux/list.h> #include <linux/stddef.h> #include <linux/spinlock.h> #include <asm/system.h> #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); struct __wait_queue { unsigned int flags; #define WQ_FLAG_EXCLUSIVE 0x01 void *private; wait_queue_func_t func; struct list_head task_list; }; struct wait_bit_key { void *flags; int bit_nr; }; struct wait_bit_queue { struct wait_bit_key key; wait_queue_t wait; }; struct __wait_queue_head { spinlock_t lock; struct list_head task_list; }; 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, \ .func = default_wake_function, \ .task_list = { NULL, NULL } } #define DECLARE_WAITQUEUE(name, tsk) \ wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk) #define __WAIT_QUEUE_HEAD_INITIALIZER(name) { \ .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ .task_list = { &(name).task_list, &(name).task_list } } #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, } extern void init_waitqueue_head(wait_queue_head_t *q); #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; } static inline int waitqueue_active(wait_queue_head_t *q) { return !list_empty(&q->task_list); } /* * Used to distinguish between sync and async io wait context: * sync i/o typically specifies a NULL wait queue entry or a wait * queue entry bound to a task (current task) to wake up. * aio specifies a wait queue entry with an async notification * callback routine, not associated with any task. */ #define is_sync_wait(wait) (!(wait) || ((wait)->private)) extern void FASTCALL(add_wait_queue(wait_queue_head_t *q, wait_queue_t * wait)); extern void FASTCALL(add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t * wait)); extern void FASTCALL(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_tail(wait_queue_head_t *head, wait_queue_t *new) { list_add_tail(&new->task_list, &head->task_list); } static inline void __remove_wait_queue(wait_queue_head_t *head, wait_queue_t *old) { list_del(&old->task_list); } void FASTCALL(__wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key)); extern void FASTCALL(__wake_up_locked(wait_queue_head_t *q, unsigned int mode)); extern void FASTCALL(__wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr)); void FASTCALL(__wake_up_bit(wait_queue_head_t *, void *, int)); int FASTCALL(__wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned)); int FASTCALL(__wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned)); void FASTCALL(wake_up_bit(void *, int)); int FASTCALL(out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned)); int FASTCALL(out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned)); wait_queue_head_t *FASTCALL(bit_waitqueue(void *, int)); #define wake_up(x) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 1, NULL) #define wake_up_nr(x, nr) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, nr, NULL) #define wake_up_all(x) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 0, NULL) #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_locked(x) __wake_up_locked((x), TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE) #define wake_up_interruptible_sync(x) __wake_up_sync((x),TASK_INTERRUPTIBLE, 1) #define __wait_event(wq, condition) \ do { \ DEFINE_WAIT(__wait); \ \ for (;;) { \ prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \ if (condition) \ break; \ schedule(); \ } \ finish_wait(&wq, &__wait); \ } while (0) /** * 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 { \ if (condition) \ break; \ __wait_event(wq, condition); \ } while (0) #define __wait_event_timeout(wq, condition, ret) \ do { \ DEFINE_WAIT(__wait); \ \ for (;;) { \ prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \ if (condition) \ break; \ ret = schedule_timeout(ret); \ if (!ret) \ break; \ } \ finish_wait(&wq, &__wait); \ } while (0) /** * 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. * * The function returns 0 if the @timeout elapsed, and the remaining * jiffies if the condition evaluated to true before the timeout elapsed. */ #define wait_event_timeout(wq, condition, timeout) \ ({ \ long __ret = timeout; \ if (!(condition)) \ __wait_event_timeout(wq, condition, __ret); \ __ret; \ }) #define __wait_event_interruptible(wq, condition, ret) \ do { \ DEFINE_WAIT(__wait); \ \ for (;;) { \ prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ if (condition) \ break; \ if (!signal_pending(current)) { \ schedule(); \ continue; \ } \ ret = -ERESTARTSYS; \ break; \ } \ finish_wait(&wq, &__wait); \ } while (0) /** * 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; \ if (!(condition)) \ __wait_event_interruptible(wq, condition, __ret); \ __ret; \ }) #define __wait_event_interruptible_timeout(wq, condition, ret) \ do { \ DEFINE_WAIT(__wait); \ \ for (;;) { \ prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ if (condition) \ break; \ if (!signal_pending(current)) { \ ret = schedule_timeout(ret); \ if (!ret) \ break; \ continue; \ } \ ret = -ERESTARTSYS; \ break; \ } \ finish_wait(&wq, &__wait); \ } while (0) /** * 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. * * 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_timeout(wq, condition, timeout) \ ({ \ long __ret = timeout; \ if (!(condition)) \ __wait_event_interruptible_timeout(wq, condition, __ret); \ __ret; \ }) #define __wait_event_interruptible_exclusive(wq, condition, ret) \ do { \ DEFINE_WAIT(__wait); \ \ for (;;) { \ prepare_to_wait_exclusive(&wq, &__wait, \ TASK_INTERRUPTIBLE); \ if (condition) \ break; \ if (!signal_pending(current)) { \ schedule(); \ continue; \ } \ ret = -ERESTARTSYS; \ break; \ } \ finish_wait(&wq, &__wait); \ } while (0) #define wait_event_interruptible_exclusive(wq, condition) \ ({ \ int __ret = 0; \ if (!(condition)) \ __wait_event_interruptible_exclusive(wq, condition, __ret);\ __ret; \ }) /* * 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 during 2.7. */ extern void FASTCALL(sleep_on(wait_queue_head_t *q)); extern long FASTCALL(sleep_on_timeout(wait_queue_head_t *q, signed long timeout)); extern void FASTCALL(interruptible_sleep_on(wait_queue_head_t *q)); extern long FASTCALL(interruptible_sleep_on_timeout(wait_queue_head_t *q, signed long timeout)); /* * Waitqueues which are removed from the waitqueue_head at wakeup time */ void FASTCALL(prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state)); void FASTCALL(prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state)); void FASTCALL(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 wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key); #define DEFINE_WAIT(name) \ wait_queue_t name = { \ .private = current, \ .func = autoremove_wake_function, \ .task_list = LIST_HEAD_INIT((name).task_list), \ } #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); \ } while (0) /** * 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 * @action: the function used to sleep, which may take special actions * @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. */ static inline int wait_on_bit(void *word, int bit, int (*action)(void *), unsigned mode) { 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 * @action: the function used to sleep, which may take special actions * @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. */ static inline int wait_on_bit_lock(void *word, int bit, int (*action)(void *), unsigned mode) { if (!test_and_set_bit(bit, word)) return 0; return out_of_line_wait_on_bit_lock(word, bit, action, mode); } #endif /* __KERNEL__ */ #endif