runtime: refactor timerQueue

Move common functions to scheduler.go. They will be used both from the
cooperative and from the threads scheduler.

src/runtime/scheduler.go

@@ -6,6 +6,8 @@ const schedulerDebug = false
 
 var mainExited bool
 
+var timerQueue *timerNode
+
 // Simple logging, for debugging.
 func scheduleLog(msg string) {
 	if schedulerDebug {
@@ -27,6 +29,34 @@ func scheduleLogChan(msg string, ch *channel, t *task.Task) {
 	}
 }
 
+func timerQueueAdd(tn *timerNode) {
+	q := &timerQueue
+	for ; *q != nil; q = &(*q).next {
+		if tn.whenTicks() < (*q).whenTicks() {
+			// this will finish earlier than the next - insert here
+			break
+		}
+	}
+	tn.next = *q
+	*q = tn
+}
+
+func timerQueueRemove(t *timer) bool {
+	removedTimer := false
+	for q := &timerQueue; *q != nil; q = &(*q).next {
+		if (*q).timer == t {
+			scheduleLog("removed timer")
+			*q = (*q).next
+			removedTimer = true
+			break
+		}
+	}
+	if !removedTimer {
+		scheduleLog("did not remove timer")
+	}
+	return removedTimer
+}
+
 // Goexit terminates the currently running goroutine. No other goroutines are affected.
 func Goexit() {
 	panicOrGoexit(nil, panicGoexit)