cmd/trace: trace error check and more logging in annotations test

This is for debugging the reported flaky tests.

Update #24081

Change-Id: Ica046928f675d69e38251a47a6f225efedce920c
Reviewed-on: https://go-review.googlesource.com/96855
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>

diff --git a/src/cmd/trace/annotations_test.go b/src/cmd/trace/annotations_test.go
index e67e02b2dbc092c78c69c4f3b1d10cc6f48a27d2..539ad81ecbdc236a18ecec189eada25bf59005e0 100644 (file)
--- a/src/cmd/trace/annotations_test.go
+++ b/src/cmd/trace/annotations_test.go
@@ -63,7 +63,9 @@ func TestAnalyzeAnnotations(t *testing.T) {
        // TODO: classify taskless spans
 
        // Run prog0 and capture the execution trace.
-       traceProgram(prog0, "TestAnalyzeAnnotations")
+       if err := traceProgram(prog0, "TestAnalyzeAnnotations"); err != nil {
+               t.Fatalf("failed to trace the program: %v", err)
+       }
 
        res, err := analyzeAnnotations()
        if err != nil {
@@ -126,7 +128,9 @@ func prog1() {
 
 func TestAnalyzeAnnotationTaskTree(t *testing.T) {
        // Run prog1 and capture the execution trace.
-       traceProgram(prog1, "TestAnalyzeAnnotationTaskTree")
+       if err := traceProgram(prog1, "TestAnalyzeAnnotationTaskTree"); err != nil {
+               t.Fatalf("failed to trace the program: %v", err)
+       }
 
        res, err := analyzeAnnotations()
        if err != nil {
@@ -208,12 +212,15 @@ func prog2() (gcTime time.Duration) {
 
 func TestAnalyzeAnnotationGC(t *testing.T) {
        var gcTime time.Duration
-       traceProgram(func() {
+       err := traceProgram(func() {
                oldGC := debug.SetGCPercent(10000) // gc, and effectively disable GC
                defer debug.SetGCPercent(oldGC)
 
                gcTime = prog2()
        }, "TestAnalyzeAnnotationGC")
+       if err != nil {
+               t.Fatalf("failed to trace the program: %v", err)
+       }
 
        res, err := analyzeAnnotations()
        if err != nil {
@@ -241,6 +248,13 @@ func TestAnalyzeAnnotationGC(t *testing.T) {
                case "taskWithGC":
                        if got <= 0 || got >= gcTime {
                                t.Errorf("%s reported %v as overlapping GC time; want (0, %v): %v", task.name, got, gcTime, task)
+                               buf := new(bytes.Buffer)
+                               fmt.Fprintln(buf, "GC Events")
+                               for _, ev := range res.gcEvents {
+                                       fmt.Fprintf(buf, " %s\n", ev)
+                               }
+                               fmt.Fprintf(buf, "%s\n", task)
+                               t.Logf("%s", buf)
                        }
                case "taskWithoutGC":
                        if got != 0 {
@@ -264,7 +278,7 @@ func traceProgram(f func(), name string) error {
        trace.Stop()
 
        saveTrace(buf, name)
-       res, err := traceparser.Parse(buf, "")
+       res, err := traceparser.Parse(buf, name+".faketrace")
        if err != nil {
                return err
        }