cmd/trace: use different colors for tasks

and assign the same colors for spans belong to the tasks
(sadly, the trace viewer will change the saturation/ligthness
for asynchronous slices so exact color mapping is impossible.
But I hope they are not too far from each other)

Change-Id: Idaaf0828a1e0dac8012d336dcefa1c6572ddca2e
Reviewed-on: https://go-review.googlesource.com/109338
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>

src/cmd/trace/trace.go

@@ -900,7 +900,7 @@ func (ctx *traceContext) emitTask(task *taskDesc, sortIndex int) {
 		Dur:   durationUsec,
 		Pid:   tasksSection,
 		Tid:   taskRow,
-		Cname: colorSeafoamGreen,
+		Cname: pickTaskColor(task.id),
 	}
 	targ := TaskArg{ID: task.id}
 	if task.create != nil {
@@ -946,7 +946,7 @@ func (ctx *traceContext) emitRegion(s regionDesc) {
 		Tid:      s.G, // only in goroutine-oriented view
 		ID:       uint64(regionID),
 		Scope:    scopeID,
-		Cname:    colorDeepMagenta,
+		Cname:    pickTaskColor(s.TaskID),
 	}
 	if s.Start != nil {
 		sl0.Stack = ctx.stack(s.Start.Stk)
@@ -961,7 +961,7 @@ func (ctx *traceContext) emitRegion(s regionDesc) {
 		Tid:      s.G,
 		ID:       uint64(regionID),
 		Scope:    scopeID,
-		Cname:    colorDeepMagenta,
+		Cname:    pickTaskColor(s.TaskID),
 		Arg:      RegionArg{TaskID: s.TaskID},
 	}
 	if s.End != nil {
@@ -1222,7 +1222,38 @@ const (
 	colorLime                  = "cq_build_passed"              // 153, 238, 102
 	colorPink                  = "cq_build_failed"              // 238, 136, 136
 	colorSilver                = "cq_build_abandoned"           // 187, 187, 187
-	colorManzGreen              = "cq_build_attempt_running"     // 222, 222, 75
+	colorManzGreen             = "cq_build_attempt_runnig"      // 222, 222, 75
 	colorKellyGreen            = "cq_build_attempt_passed"      // 108, 218, 35
-	colorFuzzyWuzzyBrown        = "cq_build_attempt_failed"      // 187, 187, 187
+	colorAnotherGrey           = "cq_build_attempt_failed"      // 187, 187, 187
 )
+
+var colorForTask = []string{
+	colorLightMauve,
+	colorOrange,
+	colorSeafoamGreen,
+	colorVistaBlue,
+	colorTan,
+	colorMidnightBlue,
+	colorIrisBlue,
+	colorDeepMagenta,
+	colorGreen,
+	colorDarkGoldenrod,
+	colorPeach,
+	colorOlive,
+	colorCornflowerBlue,
+	colorSunsetOrange,
+	colorTangerine,
+	colorShamrockGreen,
+	colorTawny,
+	colorLemon,
+	colorLime,
+	colorPink,
+	colorSilver,
+	colorManzGreen,
+	colorKellyGreen,
+}
+
+func pickTaskColor(id uint64) string {
+	idx := id % uint64(len(colorForTask))
+	return colorForTask[idx]
+}