sched: implement waitqueues

sched/wait.c

@@ -0,0 +1,73 @@
+#include <socks/sched.h>
+#include <socks/cpu.h>
+
+void wait_item_init(struct wait_item *item, struct thread *thr)
+{
+	item->w_thread = thr;
+	item->w_entry = QUEUE_ENTRY_INIT;
+}
+
+void thread_wait_begin(struct wait_item *waiter, struct waitqueue *q)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&q->wq_lock, &flags);
+
+	queue_push_back(&q->wq_waiters, &waiter->w_entry);
+	waiter->w_thread->tr_state = THREAD_SLEEPING;
+
+	spin_unlock_irqrestore(&q->wq_lock, flags);
+}
+
+void thread_wait_end(struct wait_item *waiter, struct waitqueue *q)
+{
+	waiter->w_thread->tr_state = THREAD_READY;
+
+	unsigned long flags;
+	spin_lock_irqsave(&q->wq_lock, &flags);
+
+	queue_delete(&q->wq_waiters, &waiter->w_entry);
+
+	spin_unlock_irqrestore(&q->wq_lock, flags);
+}
+
+void wakeup_queue(struct waitqueue *q)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&q->wq_lock, &flags);
+	struct queue_entry *ent = queue_pop_front(&q->wq_waiters);
+	while (ent) {
+		struct wait_item *waiter = QUEUE_CONTAINER(struct wait_item, w_entry, ent);
+		struct thread *thr = waiter->w_thread;
+		struct runqueue *rq = thr->tr_rq;
+		if (!rq) {
+			rq = cpu_rq(this_cpu());
+		}
+
+		thr->tr_state = THREAD_READY;
+		rq_enqueue(rq, thr);
+
+		ent = queue_pop_front(&q->wq_waiters);
+	}
+
+	spin_unlock_irqrestore(&q->wq_lock, flags);
+}
+
+void wakeup_one(struct waitqueue *q)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&q->wq_lock, &flags);
+	struct queue_entry *ent = queue_pop_front(&q->wq_waiters);
+	if(ent) {
+		struct wait_item *waiter = QUEUE_CONTAINER(struct wait_item, w_entry, ent);
+		struct thread *thr = waiter->w_thread;
+		struct runqueue *rq = thr->tr_rq;
+		if (!rq) {
+			rq = cpu_rq(this_cpu());
+		}
+
+		thr->tr_state = THREAD_READY;
+		rq_enqueue(rq, thr);
+	}
+
+	spin_unlock_irqrestore(&q->wq_lock, flags);
+}