avoid skew in time.Tick; remove errors from time.Seconds, time.Nanoseconds
R=r
DELTA=46 (21 added, 10 deleted, 15 changed)
OCL=20785
CL=20787
diff --git a/src/lib/time/tick.go b/src/lib/time/tick.go
index efd5ceb..d8f7eae 100644
--- a/src/lib/time/tick.go
+++ b/src/lib/time/tick.go
@@ -26,15 +26,32 @@
func Ticker(ns int64, c *chan int64) {
var tv syscall.Timeval;
+ now := time.Nanoseconds();
+ when := now;
for {
- syscall.nstotimeval(ns, &tv);
+ when += ns; // next alarm
+
+ // if c <- now took too long, skip ahead
+ if when < now {
+ // one big step
+ when += (now-when)/ns * ns;
+ }
+ for when <= now {
+ // little steps until when > now
+ when += ns
+ }
+
+ syscall.nstotimeval(when - now, &tv);
syscall.Syscall6(syscall.SYS_SELECT, 0, 0, 0, 0, syscall.TimevalPtr(&tv), 0);
- nsec, err := time.Nanoseconds();
- c <- nsec;
+ now = time.Nanoseconds();
+ c <- now;
}
}
export func Tick(ns int64) *chan int64 {
+ if ns <= 0 {
+ return nil
+ }
c := new(chan int64);
go Ticker(ns, c);
return c;
