X tracing: Polish

go/xcommon/tracing/cmd/gotrace/gotrace_test.go

+// Copyright (C) 2017  Nexedi SA and Contributors.
+//                     Kirill Smelkov <kirr@nexedi.com>
+//
+// This program is free software: you can Use, Study, Modify and Redistribute
+// it under the terms of the GNU General Public License version 3, or (at your
+// option) any later version, as published by the Free Software Foundation.
+//
+// You can also Link and Combine this program with other software covered by
+// the terms of any of the Free Software licenses or any of the Open Source
+// Initiative approved licenses and Convey the resulting work. Corresponding
+// source of such a combination shall include the source code for all other
+// software used.
+//
+// This program is distributed WITHOUT ANY WARRANTY; without even the implied
+// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+//
+// See COPYING file for full licensing terms.
+// See https://www.nexedi.com/licensing for rationale and options.
+
 package main
 
 import (
+	"bytes"
 	"fmt"
 	"go/build"
 	"io/ioutil"
@@ -31,7 +51,8 @@ const (
 	TreePrepareWork                          // prepare work tree - inital state for `gotrace gen` to run
 )
 
-// prepareTestTree copies files from src to dst recursively processing *.ok and *.rm depending on mode
+// prepareTestTree copies files from src to dst recursively processing *.ok and *.rm depending on mode.
+//
 // dst should not initially exist
 func prepareTestTree(src, dst string, mode TreePrepareMode) error {
 	err := os.MkdirAll(dst, 0777)
@@ -113,12 +134,12 @@ func diffR(patha, pathb string) (diff string, err error) {
 	return string(out), err
 }
 
-func TestGoTraceGen(t *testing.T) {
+func TestGoTrace(t *testing.T) {
 	tmp, err := ioutil.TempDir("", "t-gotrace")
 	if err != nil {
 		t.Fatal(err)
 	}
-	//defer os.RemoveAll(tmp)
+	defer os.RemoveAll(tmp)
 
 	good := tmp + "/good"
 	work := tmp + "/work"
@@ -138,9 +159,9 @@ func TestGoTraceGen(t *testing.T) {
 
 	// XXX autodetect (go list ?)
 	testv := []string{"a/pkg1", "b/pkg2", "c/pkg3", "d/pkg4"}
-	//testv := []string{"c/pkg3"}
 
 	for _, tpkg := range testv {
+		// verify `gotrace gen`
 		err = tracegen(tpkg, tBuildCtx, "" /* = local imorts disabled */)
 		if err != nil {
 			t.Errorf("%v: %v", tpkg, err)
@@ -154,5 +175,22 @@ func TestGoTraceGen(t *testing.T) {
 		if diff != "" {
 			t.Errorf("%v: gold & work differ:\n%s", tpkg, diff)
 		}
+
+		// verify `gotrace list`
+		var tlistBuf bytes.Buffer
+		err = tracelist(&tlistBuf, tpkg, tBuildCtx, "" /* = local imports disabled */)
+		if err != nil {
+			t.Fatalf("%v: %v", tpkg, err)
+		}
+
+		tlistOk, err := ioutil.ReadFile(work + "/src/" + tpkg + "/tracelist.txt")
+		if err != nil {
+			t.Fatalf("%v: %v", tpkg, err)
+		}
+
+		tlist := tlistBuf.Bytes()
+		if !bytes.Equal(tlist, tlistOk) {
+			t.Errorf("%v: tracelist differ:\nhave:\n%s\nwant:\n%s", tpkg, tlist, tlistOk)
+		}
 	}
 }

go/xcommon/tracing/cmd/gotrace/testdata/src/a/pkg1/tracelist.txt

+a/pkg1:traceDoSomething
+a/pkg1:traceNewT
+a/pkg1:traceNewTPre
+a/pkg1:traceURLParsed

go/xcommon/tracing/cmd/gotrace/testdata/src/b/pkg2/tracelist.txt

+b/pkg2:traceDoSomething

go/xcommon/tracing/cmd/gotrace/util.go

@@ -32,7 +32,7 @@ type Buffer struct {
 }
 
 func (b *Buffer) emit(format string, argv ...interface{}) {
-	fmt.Fprintf(b, format + "\n", argv...)
+	fmt.Fprintf(b, format+"\n", argv...)
 }
 
 

go/xcommon/tracing/internal/race/race.go

@@ -27,12 +27,15 @@ import "unsafe"
 // symbols are e.g. in go/src/runtime/race/race_linux_amd64.syso
 #cgo LDFLAGS: -Wl,--unresolved-symbols=ignore-in-object-files
 
+// __tsan::ThreadIgnoreBegin(__tsan::ThreadState*, unsigned long)
+// __tsan::ThreadIgnoreEnd(__tsan::ThreadState*, unsigned long)
 extern void _ZN6__tsan17ThreadIgnoreBeginEPNS_11ThreadStateEm(void *, unsigned long);
 extern void _ZN6__tsan15ThreadIgnoreEndEPNS_11ThreadStateEm(void *, unsigned long);
 */
 import "C"
 
-// NOTE runtime.RaceDisable disables only "sync" part, not "read/write"
+// Ways to tell race-detector to ignore "read/write" events from current thread.
+// NOTE runtime.RaceDisable disables only "sync" part, not "read/write".
 
 func IgnoreBegin(racectx uintptr) {
 	C._ZN6__tsan17ThreadIgnoreBeginEPNS_11ThreadStateEm(unsafe.Pointer(racectx), 0)

go/xcommon/tracing/internal/xruntime/g_typedef

@@ -10,7 +10,7 @@ govern=	# e.g. 109 for go1.9
 # goset <goexec> - set <goexec> as current go
 goset() {
 	goexec=$1
-	# go1.1 go1.2 go1.3 go1.4 go1.5 go1.6 go1.7 go1.8 go1.9 go1.10 -> go1.10`
+	# go1.1 go1.2 go1.3 go1.4 go1.5 go1.6 go1.7 go1.8 go1.9 go1.10 -> go1.10
 	gover=`$goexec list -f '{{ range context.ReleaseTags }} {{ .}}{{end}}' runtime |awk '{print $NF}'`
 	IFS=. read gomaj gomin < <(echo "$gover")
 	govern=$((${gomaj#go} * 100 + $gomin))

go/xcommon/tracing/internal/xruntime/runtime.go

@@ -18,12 +18,11 @@
 // See https://www.nexedi.com/licensing for rationale and options.
 
 package xruntime
-// stop-the-world that should probably be in xruntime, but I'm (yet) hesitating
-// to expose the API to public.
+// stop-the-world that should probably be in public xruntime, but I'm (yet)
+// hesitating to expose the API to public.
 
 import _ "unsafe"
 
-
 //go:linkname runtime_stopTheWorld runtime.stopTheWorld
 //go:linkname runtime_startTheWorld runtime.startTheWorld
 
@@ -41,7 +40,7 @@ func StopTheWorld(reason string) {
 	runtime_stopTheWorld(reason)
 }
 
-// StartTheWorld restarts the world after it was stopped by StopTheWorld
+// StartTheWorld restarts the world after it was stopped by StopTheWorld.
 func StartTheWorld() {
 	runtime_startTheWorld()
 }

go/xcommon/tracing/internal/xruntime/runtime_g.go

@@ -21,5 +21,5 @@ package xruntime
 
 //go:generate ./g_typedef
 
-// getg returns pointer to current goroutine descriptor
+// getg returns pointer to current goroutine descriptor.
 func getg() *g

go/xcommon/tracing/tracing.go

@@ -106,9 +106,9 @@ To get better understanding of what happens when it is possible to record
 events into a stream and later either visualize or postprocess them.
 This is similar to how Go execution tracer works:
 
-https://golang.org/s/go15trace
-https://golang.org/pkg/runtime/trace
-https://golang.org/cmd/trace
+	https://golang.org/s/go15trace
+	https://golang.org/pkg/runtime/trace
+	https://golang.org/cmd/trace
 
 though there it records only predefined set of events related to Go runtime.
 
@@ -146,7 +146,7 @@ a set of goroutines in tested code in question
 - produce events in correct order, and
 - at every event associated internal state is correct.
 
-TODO example
+TODO example.
 
 
 Cross package tracing
@@ -291,7 +291,7 @@ func AttachProbe(pg *ProbeGroup, listp **Probe, probe *Probe) {
 
 // Detach detaches probe from a tracepoint.
 //
-// Must be called under Lock
+// Must be called under Lock.
 func (p *Probe) Detach() {
 	verifyLocked()
 
@@ -326,7 +326,7 @@ type ProbeGroup struct {
 
 // Add adds a probe to the group.
 //
-// Must be called under Lock
+// Must be called under Lock.
 func (pg *ProbeGroup) Add(p *Probe) {
 	verifyLocked()
 	pg.probev = append(pg.probev, p)
@@ -334,7 +334,7 @@ func (pg *ProbeGroup) Add(p *Probe) {
 
 // Done detaches all probes registered to the group.
 //
-// Must be called under normal conditions, not under Lock
+// Must be called under normal conditions, not under Lock.
 func (pg *ProbeGroup) Done() {
 	verifyUnlocked()
 	Lock()

go/xcommon/tracing/tracing_test.go

@@ -114,7 +114,7 @@ func TestUseDetach(t *testing.T) {
 	go func() {
 		// delay a bit so that main goroutine first spins some time
 		// with non-empty probe list
-		time.Sleep(1*time.Millisecond)
+		time.Sleep(1 * time.Millisecond)
 
 		Lock()
 		probe.Detach()