cmd/trace: include taskless spans in /usertasks.

Change-Id: Id4e3407ba497a018d5ace92813ba8e9653d0ac7d
Reviewed-on: https://go-review.googlesource.com/104976
Reviewed-by: Heschi Kreinick <heschi@google.com>
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/trace/annotations.go

@@ -306,13 +306,15 @@ func analyzeAnnotations() (annotationAnalysisResult, error) {
 	// combine span info.
 	analyzeGoroutines(events)
 	for goid, stats := range gs {
+		// gs is a global var defined in goroutines.go as a result
+		// of analyzeGoroutines. TODO(hyangah): fix this not to depend
+		// on a 'global' var.
 		for _, s := range stats.Spans {
-			if s.TaskID == 0 {
+			if s.TaskID != 0 {
-				continue
+				task := tasks.task(s.TaskID)
+				task.goroutines[goid] = struct{}{}
+				task.spans = append(task.spans, spanDesc{UserSpanDesc: s, G: goid})
 			}
-			task := tasks.task(s.TaskID)
-			task.goroutines[goid] = struct{}{}
-			task.spans = append(task.spans, spanDesc{UserSpanDesc: s, G: goid})
 			var frame trace.Frame
 			if s.Start != nil {
 				frame = *s.Start.Stk[0]
@@ -322,7 +324,7 @@ func analyzeAnnotations() (annotationAnalysisResult, error) {
 		}
 	}
 
-	// sort spans based on the timestamps.
+	// sort spans in tasks based on the timestamps.
 	for _, task := range tasks {
 		sort.SliceStable(task.spans, func(i, j int) bool {
 			si, sj := task.spans[i].firstTimestamp(), task.spans[j].firstTimestamp()
@@ -408,7 +410,6 @@ func (tasks allTasks) task(taskID uint64) *taskDesc {
 
 func (task *taskDesc) addEvent(ev *trace.Event) {
 	if task == nil {
-		// TODO(hyangah): handle spans with no task.
 		return
 	}
 
@@ -1229,7 +1230,7 @@ function reloadTable(key, value) {
 {{range .Data}}
   <tr>
     <td> <a href="/trace?goid={{.G}}">{{.G}}</a> </td>
-    <td> <a href="/trace?taskid={{.TaskID}}">{{.TaskID}}</a> </td>
+    <td> {{if .TaskID}}<a href="/trace?taskid={{.TaskID}}">{{.TaskID}}</a>{{end}} </td>
     <td> {{prettyDuration .TotalTime}} </td>
     <td>
         <div class="stacked-bar-graph">

src/cmd/trace/annotations_test.go

@@ -10,6 +10,7 @@ import (
 	"reflect"
 	"runtime/debug"
 	"runtime/trace"
+	"sort"
 	"sync"
 	"testing"
 	"time"
@@ -98,7 +99,6 @@ func TestAnalyzeAnnotations(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to analyzeAnnotations: %v", err)
 	}
-	tasks := res.tasks
 
 	// For prog0, we expect
 	//   - task with name = "task0", with three spans.
@@ -119,14 +119,14 @@ func TestAnalyzeAnnotations(t *testing.T) {
 		},
 	}
 
-	for _, task := range tasks {
+	for _, task := range res.tasks {
 		want, ok := wantTasks[task.name]
 		if !ok {
 			t.Errorf("unexpected task: %s", task)
 			continue
 		}
 		if task.complete() != want.complete || len(task.goroutines) != want.goroutines || !reflect.DeepEqual(spanNames(task), want.spans) {
-			t.Errorf("got %v; want %+v", task, want)
+			t.Errorf("got task %v; want %+v", task, want)
 		}
 
 		delete(wantTasks, task.name)
@@ -134,6 +134,24 @@ func TestAnalyzeAnnotations(t *testing.T) {
 	if len(wantTasks) > 0 {
 		t.Errorf("no more tasks; want %+v", wantTasks)
 	}
+
+	wantSpans := []string{
+		"", // an auto-created span for the goroutine 3
+		"taskless.span",
+		"task0.span0",
+		"task0.span1",
+		"task0.span2",
+	}
+	var gotSpans []string
+	for spanID := range res.spans {
+		gotSpans = append(gotSpans, spanID.Type)
+	}
+
+	sort.Strings(wantSpans)
+	sort.Strings(gotSpans)
+	if !reflect.DeepEqual(gotSpans, wantSpans) {
+		t.Errorf("got spans %q, want spans %q", gotSpans, wantSpans)
+	}
 }
 
 // prog1 creates a task hierarchy consisting of three tasks.