diff options
Diffstat (limited to 'c_src/linux/wait.c')
-rw-r--r-- | c_src/linux/wait.c | 250 |
1 files changed, 0 insertions, 250 deletions
diff --git a/c_src/linux/wait.c b/c_src/linux/wait.c deleted file mode 100644 index b1f002b9..00000000 --- a/c_src/linux/wait.c +++ /dev/null @@ -1,250 +0,0 @@ -/* - * Generic waiting primitives. - * - * (C) 2004 Nadia Yvette Chambers, Oracle - */ - -#include <linux/completion.h> -#include <linux/sched.h> -#include <linux/wait.h> - -static inline int waitqueue_active(wait_queue_head_t *q) -{ - return !list_empty(&q->task_list); -} - -static inline void __add_wait_queue(wait_queue_head_t *head, wait_queue_t *new) -{ - list_add(&new->task_list, &head->task_list); -} - -static inline void __add_wait_queue_tail(wait_queue_head_t *head, - wait_queue_t *new) -{ - list_add_tail(&new->task_list, &head->task_list); -} - -static inline void -__add_wait_queue_tail_exclusive(wait_queue_head_t *q, wait_queue_t *wait) -{ - wait->flags |= WQ_FLAG_EXCLUSIVE; - __add_wait_queue_tail(q, wait); -} - -static inline void -__remove_wait_queue(wait_queue_head_t *head, wait_queue_t *old) -{ - list_del(&old->task_list); -} - -static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, - int nr_exclusive, int wake_flags, void *key) -{ - wait_queue_t *curr, *next; - - list_for_each_entry_safe(curr, next, &q->task_list, task_list) { - unsigned flags = curr->flags; - - if (curr->func(curr, mode, wake_flags, key) && - (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) - break; - } -} - -static void __wake_up(wait_queue_head_t *q, unsigned int mode, - int nr_exclusive, void *key) -{ - unsigned long flags; - - spin_lock_irqsave(&q->lock, flags); - __wake_up_common(q, mode, nr_exclusive, 0, key); - spin_unlock_irqrestore(&q->lock, flags); -} - -void wake_up(wait_queue_head_t *q) -{ - __wake_up(q, TASK_NORMAL, 1, NULL); -} - -void wake_up_all(wait_queue_head_t *q) -{ - __wake_up(q, TASK_NORMAL, 0, NULL); -} - -static void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr) -{ - __wake_up_common(q, mode, nr, 0, NULL); -} - -void -prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state) -{ - unsigned long flags; - - wait->flags &= ~WQ_FLAG_EXCLUSIVE; - spin_lock_irqsave(&q->lock, flags); - if (list_empty(&wait->task_list)) - __add_wait_queue(q, wait); - set_current_state(state); - spin_unlock_irqrestore(&q->lock, flags); -} - -static void -prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state) -{ - unsigned long flags; - - wait->flags |= WQ_FLAG_EXCLUSIVE; - spin_lock_irqsave(&q->lock, flags); - if (list_empty(&wait->task_list)) - __add_wait_queue_tail(q, wait); - set_current_state(state); - spin_unlock_irqrestore(&q->lock, flags); -} - -void finish_wait(wait_queue_head_t *q, wait_queue_t *wait) -{ - unsigned long flags; - - __set_current_state(TASK_RUNNING); - /* - * We can check for list emptiness outside the lock - * IFF: - * - we use the "careful" check that verifies both - * the next and prev pointers, so that there cannot - * be any half-pending updates in progress on other - * CPU's that we haven't seen yet (and that might - * still change the stack area. - * and - * - all other users take the lock (ie we can only - * have _one_ other CPU that looks at or modifies - * the list). - */ - if (!list_empty_careful(&wait->task_list)) { - spin_lock_irqsave(&q->lock, flags); - list_del_init(&wait->task_list); - spin_unlock_irqrestore(&q->lock, flags); - } -} - -int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, - void *key) -{ - return wake_up_process(curr->private); -} - -int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key) -{ - int ret = default_wake_function(wait, mode, sync, key); - - if (ret) - list_del_init(&wait->task_list); - return ret; -} - -struct wait_bit_key { - void *flags; - int bit_nr; - unsigned long timeout; -}; - -struct wait_bit_queue { - struct wait_bit_key key; - wait_queue_t wait; -}; - -static int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *arg) -{ - struct wait_bit_key *key = arg; - struct wait_bit_queue *wait_bit = - container_of(wait, struct wait_bit_queue, wait); - - return (wait_bit->key.flags == key->flags && - wait_bit->key.bit_nr == key->bit_nr && - !test_bit(key->bit_nr, key->flags)) - ? autoremove_wake_function(wait, mode, sync, key) : 0; -} - -static DECLARE_WAIT_QUEUE_HEAD(bit_wq); - -#define __WAIT_BIT_KEY_INITIALIZER(word, bit) \ - { .flags = word, .bit_nr = bit, } - -#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), \ - }, \ - } - -void wake_up_bit(void *word, int bit) -{ - struct wait_bit_key key = __WAIT_BIT_KEY_INITIALIZER(word, bit); - - if (waitqueue_active(&bit_wq)) - __wake_up(&bit_wq, TASK_NORMAL, 1, &key); -} - -void __wait_on_bit(void *word, int bit, unsigned mode) -{ - DEFINE_WAIT_BIT(wait, word, bit); - - do { - prepare_to_wait(&bit_wq, &wait.wait, mode); - if (test_bit(wait.key.bit_nr, wait.key.flags)) - schedule(); - } while (test_bit(wait.key.bit_nr, wait.key.flags)); - - finish_wait(&bit_wq, &wait.wait); -} - -void __wait_on_bit_lock(void *word, int bit, unsigned mode) -{ - DEFINE_WAIT_BIT(wait, word, bit); - - do { - prepare_to_wait_exclusive(&bit_wq, &wait.wait, mode); - if (!test_bit(wait.key.bit_nr, wait.key.flags)) - continue; - schedule(); - } while (test_and_set_bit(wait.key.bit_nr, wait.key.flags)); - finish_wait(&bit_wq, &wait.wait); -} - -void complete(struct completion *x) -{ - unsigned long flags; - - spin_lock_irqsave(&x->wait.lock, flags); - x->done++; - __wake_up_locked(&x->wait, TASK_NORMAL, 1); - spin_unlock_irqrestore(&x->wait.lock, flags); -} - -void wait_for_completion(struct completion *x) -{ - spin_lock_irq(&x->wait.lock); - - if (!x->done) { - DECLARE_WAITQUEUE(wait, current); - - __add_wait_queue_tail_exclusive(&x->wait, &wait); - do { - __set_current_state(TASK_UNINTERRUPTIBLE); - spin_unlock_irq(&x->wait.lock); - - schedule(); - spin_lock_irq(&x->wait.lock); - } while (!x->done); - __remove_wait_queue(&x->wait, &wait); - if (!x->done) - goto out; - } - x->done--; -out: - spin_unlock_irq(&x->wait.lock); -} |