eed8c02e68
New wait_event{_interruptible}_lock_irq{_cmd} macros added. This commit
moves the private wait_event_lock_irq() macro from MD to regular wait
includes, introduces new macro wait_event_lock_irq_cmd() instead of using
the old method with omitting cmd parameter which is ugly and makes a use
of new macros in the MD. It also introduces the _interruptible_ variant.
The use of new interface is when one have a special lock to protect data
structures used in the condition, or one also needs to invoke "cmd"
before putting it to sleep.
All new macros are expected to be called with the lock taken. The lock
is released before sleep and is reacquired afterwards. We will leave the
macro with the lock held.
Note to DM: IMO this should also fix theoretical race on waitqueue while
using simultaneously wait_event_lock_irq() and wait_event() because of
lack of locking around current state setting and wait queue removal.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Cc: Neil Brown <neilb@suse.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
815 lines
26 KiB
C
815 lines
26 KiB
C
#ifndef _LINUX_WAIT_H
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#define _LINUX_WAIT_H
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#include <linux/list.h>
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#include <linux/stddef.h>
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#include <linux/spinlock.h>
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#include <asm/current.h>
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#include <uapi/linux/wait.h>
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typedef struct __wait_queue wait_queue_t;
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typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int flags, void *key);
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int default_wake_function(wait_queue_t *wait, unsigned mode, int flags, void *key);
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struct __wait_queue {
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unsigned int flags;
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#define WQ_FLAG_EXCLUSIVE 0x01
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void *private;
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wait_queue_func_t func;
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struct list_head task_list;
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};
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struct wait_bit_key {
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void *flags;
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int bit_nr;
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};
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struct wait_bit_queue {
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struct wait_bit_key key;
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wait_queue_t wait;
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};
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struct __wait_queue_head {
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spinlock_t lock;
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struct list_head task_list;
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};
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typedef struct __wait_queue_head wait_queue_head_t;
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struct task_struct;
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/*
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* Macros for declaration and initialisaton of the datatypes
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*/
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#define __WAITQUEUE_INITIALIZER(name, tsk) { \
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.private = tsk, \
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.func = default_wake_function, \
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.task_list = { NULL, NULL } }
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#define DECLARE_WAITQUEUE(name, tsk) \
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wait_queue_t name = __WAITQUEUE_INITIALIZER(name, tsk)
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#define __WAIT_QUEUE_HEAD_INITIALIZER(name) { \
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.lock = __SPIN_LOCK_UNLOCKED(name.lock), \
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.task_list = { &(name).task_list, &(name).task_list } }
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#define DECLARE_WAIT_QUEUE_HEAD(name) \
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wait_queue_head_t name = __WAIT_QUEUE_HEAD_INITIALIZER(name)
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#define __WAIT_BIT_KEY_INITIALIZER(word, bit) \
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{ .flags = word, .bit_nr = bit, }
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extern void __init_waitqueue_head(wait_queue_head_t *q, const char *name, struct lock_class_key *);
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#define init_waitqueue_head(q) \
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do { \
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static struct lock_class_key __key; \
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\
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__init_waitqueue_head((q), #q, &__key); \
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} while (0)
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#ifdef CONFIG_LOCKDEP
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# define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \
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({ init_waitqueue_head(&name); name; })
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# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \
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wait_queue_head_t name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
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#else
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# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name)
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#endif
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static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p)
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{
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q->flags = 0;
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q->private = p;
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q->func = default_wake_function;
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}
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static inline void init_waitqueue_func_entry(wait_queue_t *q,
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wait_queue_func_t func)
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{
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q->flags = 0;
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q->private = NULL;
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q->func = func;
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}
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static inline int waitqueue_active(wait_queue_head_t *q)
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{
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return !list_empty(&q->task_list);
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}
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extern void add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait);
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extern void add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait);
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extern void remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait);
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static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new)
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{
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list_add(&new->task_list, &head->task_list);
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}
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/*
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* Used for wake-one threads:
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*/
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static inline void __add_wait_queue_exclusive(wait_queue_head_t *q,
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wait_queue_t *wait)
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{
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wait->flags |= WQ_FLAG_EXCLUSIVE;
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__add_wait_queue(q, wait);
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}
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static inline void __add_wait_queue_tail(wait_queue_head_t *head,
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wait_queue_t *new)
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{
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list_add_tail(&new->task_list, &head->task_list);
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}
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static inline void __add_wait_queue_tail_exclusive(wait_queue_head_t *q,
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wait_queue_t *wait)
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{
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wait->flags |= WQ_FLAG_EXCLUSIVE;
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__add_wait_queue_tail(q, wait);
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}
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static inline void __remove_wait_queue(wait_queue_head_t *head,
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wait_queue_t *old)
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{
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list_del(&old->task_list);
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}
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void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr, void *key);
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void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key);
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void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr,
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void *key);
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void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr);
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void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr);
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void __wake_up_bit(wait_queue_head_t *, void *, int);
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int __wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned);
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int __wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned);
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void wake_up_bit(void *, int);
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int out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned);
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int out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned);
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wait_queue_head_t *bit_waitqueue(void *, int);
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#define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL)
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#define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL)
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#define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL)
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#define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL, 1)
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#define wake_up_all_locked(x) __wake_up_locked((x), TASK_NORMAL, 0)
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#define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
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#define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
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#define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
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#define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE, 1)
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/*
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* Wakeup macros to be used to report events to the targets.
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*/
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#define wake_up_poll(x, m) \
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__wake_up(x, TASK_NORMAL, 1, (void *) (m))
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#define wake_up_locked_poll(x, m) \
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__wake_up_locked_key((x), TASK_NORMAL, (void *) (m))
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#define wake_up_interruptible_poll(x, m) \
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__wake_up(x, TASK_INTERRUPTIBLE, 1, (void *) (m))
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#define wake_up_interruptible_sync_poll(x, m) \
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__wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, (void *) (m))
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#define __wait_event(wq, condition) \
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do { \
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DEFINE_WAIT(__wait); \
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\
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for (;;) { \
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prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
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if (condition) \
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break; \
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schedule(); \
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} \
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finish_wait(&wq, &__wait); \
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} while (0)
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/**
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* wait_event - sleep until a condition gets true
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* @wq: the waitqueue to wait on
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* @condition: a C expression for the event to wait for
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*
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* The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
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* @condition evaluates to true. The @condition is checked each time
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* the waitqueue @wq is woken up.
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*
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* wake_up() has to be called after changing any variable that could
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* change the result of the wait condition.
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*/
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#define wait_event(wq, condition) \
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do { \
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if (condition) \
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break; \
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__wait_event(wq, condition); \
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} while (0)
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#define __wait_event_timeout(wq, condition, ret) \
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do { \
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DEFINE_WAIT(__wait); \
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\
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for (;;) { \
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prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
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if (condition) \
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break; \
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ret = schedule_timeout(ret); \
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if (!ret) \
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break; \
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} \
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finish_wait(&wq, &__wait); \
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} while (0)
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/**
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* wait_event_timeout - sleep until a condition gets true or a timeout elapses
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* @wq: the waitqueue to wait on
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* @condition: a C expression for the event to wait for
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* @timeout: timeout, in jiffies
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*
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* The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
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* @condition evaluates to true. The @condition is checked each time
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* the waitqueue @wq is woken up.
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*
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* wake_up() has to be called after changing any variable that could
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* change the result of the wait condition.
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*
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* The function returns 0 if the @timeout elapsed, and the remaining
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* jiffies if the condition evaluated to true before the timeout elapsed.
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*/
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#define wait_event_timeout(wq, condition, timeout) \
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({ \
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long __ret = timeout; \
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if (!(condition)) \
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__wait_event_timeout(wq, condition, __ret); \
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__ret; \
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})
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#define __wait_event_interruptible(wq, condition, ret) \
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do { \
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DEFINE_WAIT(__wait); \
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\
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for (;;) { \
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prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
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if (condition) \
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break; \
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if (!signal_pending(current)) { \
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schedule(); \
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continue; \
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} \
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ret = -ERESTARTSYS; \
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break; \
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} \
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finish_wait(&wq, &__wait); \
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} while (0)
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/**
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* wait_event_interruptible - sleep until a condition gets true
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* @wq: the waitqueue to wait on
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* @condition: a C expression for the event to wait for
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*
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* The process is put to sleep (TASK_INTERRUPTIBLE) until the
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* @condition evaluates to true or a signal is received.
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* The @condition is checked each time the waitqueue @wq is woken up.
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*
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* wake_up() has to be called after changing any variable that could
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* change the result of the wait condition.
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*
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* The function will return -ERESTARTSYS if it was interrupted by a
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* signal and 0 if @condition evaluated to true.
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*/
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#define wait_event_interruptible(wq, condition) \
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({ \
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int __ret = 0; \
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if (!(condition)) \
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__wait_event_interruptible(wq, condition, __ret); \
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__ret; \
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})
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#define __wait_event_interruptible_timeout(wq, condition, ret) \
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do { \
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DEFINE_WAIT(__wait); \
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\
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for (;;) { \
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prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
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if (condition) \
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break; \
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if (!signal_pending(current)) { \
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ret = schedule_timeout(ret); \
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if (!ret) \
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break; \
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continue; \
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} \
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ret = -ERESTARTSYS; \
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break; \
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} \
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finish_wait(&wq, &__wait); \
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} while (0)
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/**
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* wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
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* @wq: the waitqueue to wait on
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* @condition: a C expression for the event to wait for
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* @timeout: timeout, in jiffies
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*
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* The process is put to sleep (TASK_INTERRUPTIBLE) until the
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* @condition evaluates to true or a signal is received.
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* The @condition is checked each time the waitqueue @wq is woken up.
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*
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* wake_up() has to be called after changing any variable that could
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* change the result of the wait condition.
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*
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* The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
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* was interrupted by a signal, and the remaining jiffies otherwise
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* if the condition evaluated to true before the timeout elapsed.
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*/
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#define wait_event_interruptible_timeout(wq, condition, timeout) \
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({ \
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long __ret = timeout; \
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if (!(condition)) \
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__wait_event_interruptible_timeout(wq, condition, __ret); \
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__ret; \
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})
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#define __wait_event_interruptible_exclusive(wq, condition, ret) \
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do { \
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DEFINE_WAIT(__wait); \
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\
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for (;;) { \
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prepare_to_wait_exclusive(&wq, &__wait, \
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TASK_INTERRUPTIBLE); \
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if (condition) { \
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finish_wait(&wq, &__wait); \
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break; \
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} \
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if (!signal_pending(current)) { \
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schedule(); \
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continue; \
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} \
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ret = -ERESTARTSYS; \
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abort_exclusive_wait(&wq, &__wait, \
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TASK_INTERRUPTIBLE, NULL); \
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break; \
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} \
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} while (0)
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#define wait_event_interruptible_exclusive(wq, condition) \
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({ \
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int __ret = 0; \
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if (!(condition)) \
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__wait_event_interruptible_exclusive(wq, condition, __ret);\
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__ret; \
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})
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#define __wait_event_interruptible_locked(wq, condition, exclusive, irq) \
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({ \
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int __ret = 0; \
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DEFINE_WAIT(__wait); \
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if (exclusive) \
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__wait.flags |= WQ_FLAG_EXCLUSIVE; \
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do { \
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if (likely(list_empty(&__wait.task_list))) \
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__add_wait_queue_tail(&(wq), &__wait); \
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set_current_state(TASK_INTERRUPTIBLE); \
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if (signal_pending(current)) { \
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__ret = -ERESTARTSYS; \
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break; \
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} \
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if (irq) \
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spin_unlock_irq(&(wq).lock); \
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else \
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spin_unlock(&(wq).lock); \
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schedule(); \
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if (irq) \
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spin_lock_irq(&(wq).lock); \
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else \
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spin_lock(&(wq).lock); \
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} while (!(condition)); \
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__remove_wait_queue(&(wq), &__wait); \
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__set_current_state(TASK_RUNNING); \
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__ret; \
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})
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/**
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* wait_event_interruptible_locked - sleep until a condition gets true
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* @wq: the waitqueue to wait on
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* @condition: a C expression for the event to wait for
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*
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* The process is put to sleep (TASK_INTERRUPTIBLE) until the
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* @condition evaluates to true or a signal is received.
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* The @condition is checked each time the waitqueue @wq is woken up.
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*
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* It must be called with wq.lock being held. This spinlock is
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* unlocked while sleeping but @condition testing is done while lock
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* is held and when this macro exits the lock is held.
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*
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* The lock is locked/unlocked using spin_lock()/spin_unlock()
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* functions which must match the way they are locked/unlocked outside
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* of this macro.
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*
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* wake_up_locked() has to be called after changing any variable that could
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* change the result of the wait condition.
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*
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* The function will return -ERESTARTSYS if it was interrupted by a
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* signal and 0 if @condition evaluated to true.
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*/
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#define wait_event_interruptible_locked(wq, condition) \
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((condition) \
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? 0 : __wait_event_interruptible_locked(wq, condition, 0, 0))
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/**
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* wait_event_interruptible_locked_irq - sleep until a condition gets true
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* @wq: the waitqueue to wait on
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* @condition: a C expression for the event to wait for
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*
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* The process is put to sleep (TASK_INTERRUPTIBLE) until the
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* @condition evaluates to true or a signal is received.
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* The @condition is checked each time the waitqueue @wq is woken up.
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*
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* It must be called with wq.lock being held. This spinlock is
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* unlocked while sleeping but @condition testing is done while lock
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* is held and when this macro exits the lock is held.
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*
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* The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
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* functions which must match the way they are locked/unlocked outside
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* of this macro.
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*
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* wake_up_locked() has to be called after changing any variable that could
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* change the result of the wait condition.
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*
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* The function will return -ERESTARTSYS if it was interrupted by a
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* signal and 0 if @condition evaluated to true.
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*/
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#define wait_event_interruptible_locked_irq(wq, condition) \
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((condition) \
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? 0 : __wait_event_interruptible_locked(wq, condition, 0, 1))
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|
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/**
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* wait_event_interruptible_exclusive_locked - sleep exclusively until a condition gets true
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* @wq: the waitqueue to wait on
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* @condition: a C expression for the event to wait for
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*
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* The process is put to sleep (TASK_INTERRUPTIBLE) until the
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* @condition evaluates to true or a signal is received.
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* The @condition is checked each time the waitqueue @wq is woken up.
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*
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* It must be called with wq.lock being held. This spinlock is
|
|
* unlocked while sleeping but @condition testing is done while lock
|
|
* is held and when this macro exits the lock is held.
|
|
*
|
|
* The lock is locked/unlocked using spin_lock()/spin_unlock()
|
|
* functions which must match the way they are locked/unlocked outside
|
|
* of this macro.
|
|
*
|
|
* The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
|
|
* set thus when other process waits process on the list if this
|
|
* process is awaken further processes are not considered.
|
|
*
|
|
* wake_up_locked() has to be called after changing any variable that could
|
|
* change the result of the wait condition.
|
|
*
|
|
* The function will return -ERESTARTSYS if it was interrupted by a
|
|
* signal and 0 if @condition evaluated to true.
|
|
*/
|
|
#define wait_event_interruptible_exclusive_locked(wq, condition) \
|
|
((condition) \
|
|
? 0 : __wait_event_interruptible_locked(wq, condition, 1, 0))
|
|
|
|
/**
|
|
* wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true
|
|
* @wq: the waitqueue to wait on
|
|
* @condition: a C expression for the event to wait for
|
|
*
|
|
* The process is put to sleep (TASK_INTERRUPTIBLE) until the
|
|
* @condition evaluates to true or a signal is received.
|
|
* The @condition is checked each time the waitqueue @wq is woken up.
|
|
*
|
|
* It must be called with wq.lock being held. This spinlock is
|
|
* unlocked while sleeping but @condition testing is done while lock
|
|
* is held and when this macro exits the lock is held.
|
|
*
|
|
* The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
|
|
* functions which must match the way they are locked/unlocked outside
|
|
* of this macro.
|
|
*
|
|
* The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
|
|
* set thus when other process waits process on the list if this
|
|
* process is awaken further processes are not considered.
|
|
*
|
|
* wake_up_locked() has to be called after changing any variable that could
|
|
* change the result of the wait condition.
|
|
*
|
|
* The function will return -ERESTARTSYS if it was interrupted by a
|
|
* signal and 0 if @condition evaluated to true.
|
|
*/
|
|
#define wait_event_interruptible_exclusive_locked_irq(wq, condition) \
|
|
((condition) \
|
|
? 0 : __wait_event_interruptible_locked(wq, condition, 1, 1))
|
|
|
|
|
|
|
|
#define __wait_event_killable(wq, condition, ret) \
|
|
do { \
|
|
DEFINE_WAIT(__wait); \
|
|
\
|
|
for (;;) { \
|
|
prepare_to_wait(&wq, &__wait, TASK_KILLABLE); \
|
|
if (condition) \
|
|
break; \
|
|
if (!fatal_signal_pending(current)) { \
|
|
schedule(); \
|
|
continue; \
|
|
} \
|
|
ret = -ERESTARTSYS; \
|
|
break; \
|
|
} \
|
|
finish_wait(&wq, &__wait); \
|
|
} while (0)
|
|
|
|
/**
|
|
* 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; \
|
|
if (!(condition)) \
|
|
__wait_event_killable(wq, condition, __ret); \
|
|
__ret; \
|
|
})
|
|
|
|
|
|
#define __wait_event_lock_irq(wq, condition, lock, cmd) \
|
|
do { \
|
|
DEFINE_WAIT(__wait); \
|
|
\
|
|
for (;;) { \
|
|
prepare_to_wait(&wq, &__wait, TASK_UNINTERRUPTIBLE); \
|
|
if (condition) \
|
|
break; \
|
|
spin_unlock_irq(&lock); \
|
|
cmd; \
|
|
schedule(); \
|
|
spin_lock_irq(&lock); \
|
|
} \
|
|
finish_wait(&wq, &__wait); \
|
|
} while (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: 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, ret, cmd) \
|
|
do { \
|
|
DEFINE_WAIT(__wait); \
|
|
\
|
|
for (;;) { \
|
|
prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE); \
|
|
if (condition) \
|
|
break; \
|
|
if (signal_pending(current)) { \
|
|
ret = -ERESTARTSYS; \
|
|
break; \
|
|
} \
|
|
spin_unlock_irq(&lock); \
|
|
cmd; \
|
|
schedule(); \
|
|
spin_lock_irq(&lock); \
|
|
} \
|
|
finish_wait(&wq, &__wait); \
|
|
} while (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: 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)) \
|
|
__wait_event_interruptible_lock_irq(wq, condition, \
|
|
lock, __ret, 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)) \
|
|
__wait_event_interruptible_lock_irq(wq, condition, \
|
|
lock, __ret, ); \
|
|
__ret; \
|
|
})
|
|
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
extern void sleep_on(wait_queue_head_t *q);
|
|
extern long sleep_on_timeout(wait_queue_head_t *q,
|
|
signed long timeout);
|
|
extern void interruptible_sleep_on(wait_queue_head_t *q);
|
|
extern long interruptible_sleep_on_timeout(wait_queue_head_t *q,
|
|
signed long timeout);
|
|
|
|
/*
|
|
* 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);
|
|
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);
|
|
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)
|
|
|
|
/**
|
|
* 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
|