kitten/kernel/waitq.c

   1 #include <lwk/kernel.h>
   2 #include <lwk/waitq.h>
   3 #include <lwk/sched.h>
   4
   5 void
   6 waitq_init(waitq_t *waitq)
   7 {
   8         spin_lock_init(&waitq->lock);
   9         list_head_init(&waitq->waitq);
  10 }
  11
  12 void
  13 waitq_init_entry(waitq_entry_t *entry, struct task_struct *task)
  14 {
  15         entry->task = task;
  16         list_head_init(&entry->link);
  17 }
  18
  19 bool
  20 waitq_active(waitq_t *waitq)
  21 {
  22         bool active;
  23         unsigned long irqstate;
  24
  25         spin_lock_irqsave(&waitq->lock, irqstate);
  26         active = !list_empty(&waitq->waitq);
  27         spin_unlock_irqrestore(&waitq->lock, irqstate);
  28
  29         return active;
  30 }
  31
  32 void
  33 waitq_add_entry(waitq_t *waitq, waitq_entry_t *entry)
  34 {
  35         unsigned long irqstate;
  36
  37         spin_lock_irqsave(&waitq->lock, irqstate);
  38         BUG_ON(!list_empty(&entry->link));
  39         list_add(&entry->link, &waitq->waitq);
  40         spin_unlock_irqrestore(&waitq->lock, irqstate);
  41 }
  42
  43 void
  44 waitq_remove_entry(waitq_t *waitq, waitq_entry_t *entry)
  45 {
  46         unsigned long irqstate;
  47
  48         spin_lock_irqsave(&waitq->lock, irqstate);
  49         BUG_ON(list_empty(&entry->link));
  50         list_del_init(&entry->link);
  51         spin_unlock_irqrestore(&waitq->lock, irqstate);
  52 }
  53
  54 void
  55 waitq_prepare_to_wait(waitq_t *waitq, waitq_entry_t *entry, taskstate_t state)
  56 {
  57         unsigned long irqstate;
  58
  59         spin_lock_irqsave(&waitq->lock, irqstate);
  60         if (list_empty(&entry->link))
  61                 list_add(&entry->link, &waitq->waitq);
  62         set_mb(entry->task->state, state);
  63         spin_unlock_irqrestore(&waitq->lock, irqstate);
  64 }
  65
  66 void
  67 waitq_finish_wait(waitq_t *waitq, waitq_entry_t *entry)
  68 {
  69         set_mb(entry->task->state, TASKSTATE_READY);
  70         waitq_remove_entry(waitq, entry);
  71 }
  72
  73 void
  74 waitq_wakeup(waitq_t *waitq)
  75 {
  76         unsigned long irqstate;
  77         struct list_head *tmp;
  78         waitq_entry_t *entry;
  79
  80         spin_lock_irqsave(&waitq->lock, irqstate);
  81         list_for_each(tmp, &waitq->waitq) {
  82                 entry  = list_entry(tmp, waitq_entry_t, link);
  83                 sched_wakeup_task(
  84                         entry->task,
  85                         (TASKSTATE_UNINTERRUPTIBLE | TASKSTATE_INTERRUPTIBLE)
  86                 );
  87         }
  88         spin_unlock_irqrestore(&waitq->lock, irqstate);
  89 }