X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Flinux%2Fwait.h;h=34f41e7901ff9c392cc1741f269be82c22b9ff83;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=17bdd85d7ff19875255c877fb1f4a3c2b105f779;hpb=5273a3df6485dc2ad6aa7ddd441b9a21970f003b;p=linux-2.6.git diff --git a/include/linux/wait.h b/include/linux/wait.h index 17bdd85d7..34f41e790 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -3,11 +3,20 @@ #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 @@ -15,32 +24,44 @@ #include #include #include +#include typedef struct __wait_queue wait_queue_t; -typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int sync); -extern int default_wake_function(wait_queue_t *wait, unsigned mode, int sync); +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 - struct task_struct * task; + 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) { \ - .task = tsk, \ + .private = tsk, \ .func = default_wake_function, \ .task_list = { NULL, NULL } } @@ -54,16 +75,19 @@ typedef struct __wait_queue_head wait_queue_head_t; #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, } + static inline void init_waitqueue_head(wait_queue_head_t *q) { - q->lock = SPIN_LOCK_UNLOCKED; + spin_lock_init(&q->lock); INIT_LIST_HEAD(&q->task_list); } static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p) { q->flags = 0; - q->task = p; + q->private = p; q->func = default_wake_function; } @@ -71,7 +95,7 @@ static inline void init_waitqueue_func_entry(wait_queue_t *q, wait_queue_func_t func) { q->flags = 0; - q->task = NULL; + q->private = NULL; q->func = func; } @@ -80,9 +104,18 @@ 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)); +extern int 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) { @@ -104,36 +137,51 @@ static inline void __remove_wait_queue(wait_queue_head_t *head, list_del(&old->task_list); } -extern void FASTCALL(__wake_up(wait_queue_head_t *q, unsigned int mode, int nr)); +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)); - -#define wake_up(x) __wake_up((x),TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 1) -#define wake_up_nr(x, nr) __wake_up((x),TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, nr) -#define wake_up_all(x) __wake_up((x),TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 0) -#define wake_up_all_sync(x) __wake_up_sync((x),TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 0) -#define wake_up_interruptible(x) __wake_up((x),TASK_INTERRUPTIBLE, 1) -#define wake_up_interruptible_nr(x, nr) __wake_up((x),TASK_INTERRUPTIBLE, nr) -#define wake_up_interruptible_all(x) __wake_up((x),TASK_INTERRUPTIBLE, 0) +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 { \ - wait_queue_t __wait; \ - init_waitqueue_entry(&__wait, current); \ + DEFINE_WAIT(__wait); \ \ - add_wait_queue(&wq, &__wait); \ for (;;) { \ - set_current_state(TASK_UNINTERRUPTIBLE); \ + prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \ if (condition) \ break; \ schedule(); \ } \ - current->state = TASK_RUNNING; \ - remove_wait_queue(&wq, &__wait); \ + 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) \ @@ -141,14 +189,51 @@ do { \ __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 { \ - wait_queue_t __wait; \ - init_waitqueue_entry(&__wait, current); \ + DEFINE_WAIT(__wait); \ \ - add_wait_queue(&wq, &__wait); \ for (;;) { \ - set_current_state(TASK_INTERRUPTIBLE); \ + prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ if (condition) \ break; \ if (!signal_pending(current)) { \ @@ -158,10 +243,24 @@ do { \ ret = -ERESTARTSYS; \ break; \ } \ - current->state = TASK_RUNNING; \ - remove_wait_queue(&wq, &__wait); \ + 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; \ @@ -172,12 +271,10 @@ do { \ #define __wait_event_interruptible_timeout(wq, condition, ret) \ do { \ - wait_queue_t __wait; \ - init_waitqueue_entry(&__wait, current); \ + DEFINE_WAIT(__wait); \ \ - add_wait_queue(&wq, &__wait); \ for (;;) { \ - set_current_state(TASK_INTERRUPTIBLE); \ + prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \ if (condition) \ break; \ if (!signal_pending(current)) { \ @@ -189,10 +286,26 @@ do { \ ret = -ERESTARTSYS; \ break; \ } \ - current->state = TASK_RUNNING; \ - remove_wait_queue(&wq, &__wait); \ + 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; \ @@ -200,7 +313,34 @@ do { \ __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. */ @@ -225,10 +365,10 @@ static inline void remove_wait_queue_locked(wait_queue_head_t *q, * 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, +extern void __deprecated FASTCALL(sleep_on(wait_queue_head_t *q)); +extern long __deprecated FASTCALL(sleep_on_timeout(wait_queue_head_t *q, signed long timeout)); -extern void FASTCALL(interruptible_sleep_on(wait_queue_head_t *q)); +extern void __deprecated FASTCALL(interruptible_sleep_on(wait_queue_head_t *q)); extern long FASTCALL(interruptible_sleep_on_timeout(wait_queue_head_t *q, signed long timeout)); @@ -240,23 +380,79 @@ void FASTCALL(prepare_to_wait(wait_queue_head_t *q, 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); +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 = { \ - .task = current, \ + .private = current, \ .func = autoremove_wake_function, \ - .task_list = { .next = &name.task_list, \ - .prev = &name.task_list, \ - }, \ + .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->task = current; \ - wait->func = autoremove_wake_function; \ - INIT_LIST_HEAD(&wait->task_list); \ + (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__ */