internal/trace: change Less to make sorting events deterministice

    The existing code just used timestamps. The new code uses more fields
    when timestamps are equal.

	Revised to shorten code per reviewer comments.

Change-Id: Ibd0824d0acd7644484d536b1a754a0da156fac3d
Reviewed-on: https://go-review.googlesource.com/113721
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>

diff --git a/src/internal/trace/order.go b/src/internal/trace/order.go
index 36ed58d675aa7aa104079543a2314f403df5f9dd..d0b58301d62d6e7a0ecb24daf85dbc9fd5f576a6 100644 (file)
--- a/src/internal/trace/order.go
+++ b/src/internal/trace/order.go
@@ -133,7 +133,7 @@ func order1007(m map[int][]*Event) (events []*Event, err error) {
                        ev.Ts = ts
                }
        }
-       sort.Stable(eventList(events))
+       sort.Sort(eventList(events))
 
        return
 }
@@ -243,7 +243,20 @@ func (l orderEventList) Len() int {
 }
 
 func (l orderEventList) Less(i, j int) bool {
-       return l[i].ev.Ts < l[j].ev.Ts
+       a, b := l[i].ev, l[j].ev
+       if a.Ts != b.Ts {
+               return a.Ts < b.Ts
+       }
+       if a.Type != b.Type {
+               return a.Type < b.Type
+       }
+       if a.P != b.P {
+               return a.P < b.P
+       }
+       if a.G != b.G {
+               return a.G < b.G
+       }
+       return a.Args[0] < b.Args[0]
 }
 
 func (l orderEventList) Swap(i, j int) {