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 {
@@ -1193,36 +1193,67 @@ func viewerDataTraceConsumer(w io.Writer, start, end int64) traceConsumer {
 // https://github.com/catapult-project/catapult/blob/master/tracing/tracing/base/color_scheme.html#L50
 // The chrome trace viewer allows only those as cname values.
 const (
-	colorLightMauve      string = "thread_state_uninterruptible" // 182, 125, 143
-	colorOrange                 = "thread_state_iowait"          // 255, 140, 0
-	colorSeafoamGreen           = "thread_state_running"         // 126, 200, 148
-	colorVistaBlue              = "thread_state_runnable"        // 133, 160, 210
-	colorTan                    = "thread_state_unknown"         // 199, 155, 125
-	colorIrisBlue               = "background_memory_dump"       // 0, 180, 180
-	colorMidnightBlue           = "light_memory_dump"            // 0, 0, 180
-	colorDeepMagenta            = "detailed_memory_dump"         // 180, 0, 180
-	colorBlue                   = "vsync_highlight_color"        // 0, 0, 255
-	colorGrey                   = "generic_work"                 // 125, 125, 125
-	colorGreen                  = "good"                         // 0, 125, 0
-	colorDarkGoldenrod          = "bad"                          // 180, 125, 0
-	colorPeach                  = "terrible"                     // 180, 0, 0
-	colorBlack                  = "black"                        // 0, 0, 0
-	colorLightGrey              = "grey"                         // 221, 221, 221
-	colorWhite                  = "white"                        // 255, 255, 255
-	colorYellow                 = "yellow"                       // 255, 255, 0
-	colorOlive                  = "olive"                        // 100, 100, 0
-	colorCornflowerBlue         = "rail_response"                // 67, 135, 253
-	colorSunsetOrange           = "rail_animation"               // 244, 74, 63
-	colorTangerine              = "rail_idle"                    // 238, 142, 0
-	colorShamrockGreen          = "rail_load"                    // 13, 168, 97
-	colorGreenishYellow         = "startup"                      // 230, 230, 0
-	colorDarkGrey               = "heap_dump_stack_frame"        // 128, 128, 128
-	colorTawny                  = "heap_dump_child_node_arrow"   // 204, 102, 0
-	colorLemon                  = "cq_build_running"             // 255, 255, 119
-	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
-	colorKellyGreen             = "cq_build_attempt_passed"      // 108, 218, 35
-	colorFuzzyWuzzyBrown        = "cq_build_attempt_failed"      // 187, 187, 187
+	colorLightMauve     string = "thread_state_uninterruptible" // 182, 125, 143
+	colorOrange                = "thread_state_iowait"          // 255, 140, 0
+	colorSeafoamGreen          = "thread_state_running"         // 126, 200, 148
+	colorVistaBlue             = "thread_state_runnable"        // 133, 160, 210
+	colorTan                   = "thread_state_unknown"         // 199, 155, 125
+	colorIrisBlue              = "background_memory_dump"       // 0, 180, 180
+	colorMidnightBlue          = "light_memory_dump"            // 0, 0, 180
+	colorDeepMagenta           = "detailed_memory_dump"         // 180, 0, 180
+	colorBlue                  = "vsync_highlight_color"        // 0, 0, 255
+	colorGrey                  = "generic_work"                 // 125, 125, 125
+	colorGreen                 = "good"                         // 0, 125, 0
+	colorDarkGoldenrod         = "bad"                          // 180, 125, 0
+	colorPeach                 = "terrible"                     // 180, 0, 0
+	colorBlack                 = "black"                        // 0, 0, 0
+	colorLightGrey             = "grey"                         // 221, 221, 221
+	colorWhite                 = "white"                        // 255, 255, 255
+	colorYellow                = "yellow"                       // 255, 255, 0
+	colorOlive                 = "olive"                        // 100, 100, 0
+	colorCornflowerBlue        = "rail_response"                // 67, 135, 253
+	colorSunsetOrange          = "rail_animation"               // 244, 74, 63
+	colorTangerine             = "rail_idle"                    // 238, 142, 0
+	colorShamrockGreen         = "rail_load"                    // 13, 168, 97
+	colorGreenishYellow        = "startup"                      // 230, 230, 0
+	colorDarkGrey              = "heap_dump_stack_frame"        // 128, 128, 128
+	colorTawny                 = "heap_dump_child_node_arrow"   // 204, 102, 0
+	colorLemon                 = "cq_build_running"             // 255, 255, 119
+	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_runnig"      // 222, 222, 75
+	colorKellyGreen            = "cq_build_attempt_passed"      // 108, 218, 35
+	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]
+}