sched: implement waitqueues

include/socks/sched.h

@@ -12,10 +12,27 @@
 #define PRIO_MAX 32
 #define THREAD_KSTACK_ORDER VM_PAGE_4K
 
+#define wait_event(wq, cond) \
+	({ \
+	struct thread *self = current_thread(); \
+	struct wait_item waiter; \
+	wait_item_init(&waiter, self); \
+	for (;;) { \
+		thread_wait_begin(&waiter, wq); \
+		if (cond) { \
+			break; \
+		} \
+		schedule(SCHED_NORMAL); \
+	} \
+	thread_wait_end(&waiter, wq); \
+	})
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+struct runqueue;
+
 enum task_state {
 	TASK_RUNNING,
 	TASK_STOPPED,
@@ -83,6 +100,8 @@ struct thread {
 
 	uintptr_t tr_sp, tr_bp;
 
+	struct runqueue *tr_rq;
+
 	struct queue_entry tr_threads;
 	struct queue_entry tr_rqentry;
 
@@ -174,6 +193,13 @@ extern void remove_timer(struct timer *timer);
 extern unsigned long schedule_timeout(unsigned long clock_ticks);
 extern unsigned long milli_sleep(unsigned long ms);
 
+extern void wait_item_init(struct wait_item *item, struct thread *thr);
+extern void thread_wait_begin(struct wait_item *waiter, struct waitqueue *q);
+extern void thread_wait_end(struct wait_item *waiter, struct waitqueue *q);
+extern void wait_on_queue(struct waitqueue *q);
+extern void wakeup_queue(struct waitqueue *q);
+extern void wakeup_one(struct waitqueue *q);
+
 #ifdef __cplusplus
 }
 #endif