1 files changed, 333 insertions, 0 deletions
diff --git a/src/runtime/trace/trace_stack_test.go b/src/runtime/trace/trace_stack_test.go
new file mode 100644
index 0000000..be3adc9
--- /dev/null
+++ b/src/runtime/trace/trace_stack_test.go
@@ -0,0 +1,333 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package trace_test
+
+import (
+	"bytes"
+	"fmt"
+	"internal/testenv"
+	"internal/trace"
+	"net"
+	"os"
+	"runtime"
+	. "runtime/trace"
+	"strings"
+	"sync"
+	"testing"
+	"text/tabwriter"
+	"time"
+)
+
+// TestTraceSymbolize tests symbolization and that events has proper stacks.
+// In particular that we strip bottom uninteresting frames like goexit,
+// top uninteresting frames (runtime guts).
+func TestTraceSymbolize(t *testing.T) {
+	skipTraceSymbolizeTestIfNecessary(t)
+
+	buf := new(bytes.Buffer)
+	if err := Start(buf); err != nil {
+		t.Fatalf("failed to start tracing: %v", err)
+	}
+	defer Stop() // in case of early return
+
+	// Now we will do a bunch of things for which we verify stacks later.
+	// It is impossible to ensure that a goroutine has actually blocked
+	// on a channel, in a select or otherwise. So we kick off goroutines
+	// that need to block first in the hope that while we are executing
+	// the rest of the test, they will block.
+	go func() { // func1
+		select {}
+	}()
+	go func() { // func2
+		var c chan int
+		c <- 0
+	}()
+	go func() { // func3
+		var c chan int
+		<-c
+	}()
+	done1 := make(chan bool)
+	go func() { // func4
+		<-done1
+	}()
+	done2 := make(chan bool)
+	go func() { // func5
+		done2 <- true
+	}()
+	c1 := make(chan int)
+	c2 := make(chan int)
+	go func() { // func6
+		select {
+		case <-c1:
+		case <-c2:
+		}
+	}()
+	var mu sync.Mutex
+	mu.Lock()
+	go func() { // func7
+		mu.Lock()
+		mu.Unlock()
+	}()
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() { // func8
+		wg.Wait()
+	}()
+	cv := sync.NewCond(&sync.Mutex{})
+	go func() { // func9
+		cv.L.Lock()
+		cv.Wait()
+		cv.L.Unlock()
+	}()
+	ln, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("failed to listen: %v", err)
+	}
+	go func() { // func10
+		c, err := ln.Accept()
+		if err != nil {
+			t.Errorf("failed to accept: %v", err)
+			return
+		}
+		c.Close()
+	}()
+	rp, wp, err := os.Pipe()
+	if err != nil {
+		t.Fatalf("failed to create a pipe: %v", err)
+	}
+	defer rp.Close()
+	defer wp.Close()
+	pipeReadDone := make(chan bool)
+	go func() { // func11
+		var data [1]byte
+		rp.Read(data[:])
+		pipeReadDone <- true
+	}()
+
+	time.Sleep(100 * time.Millisecond)
+	runtime.GC()
+	runtime.Gosched()
+	time.Sleep(100 * time.Millisecond) // the last chance for the goroutines above to block
+	done1 <- true
+	<-done2
+	select {
+	case c1 <- 0:
+	case c2 <- 0:
+	}
+	mu.Unlock()
+	wg.Done()
+	cv.Signal()
+	c, err := net.Dial("tcp", ln.Addr().String())
+	if err != nil {
+		t.Fatalf("failed to dial: %v", err)
+	}
+	c.Close()
+	var data [1]byte
+	wp.Write(data[:])
+	<-pipeReadDone
+
+	oldGoMaxProcs := runtime.GOMAXPROCS(0)
+	runtime.GOMAXPROCS(oldGoMaxProcs + 1)
+
+	Stop()
+
+	runtime.GOMAXPROCS(oldGoMaxProcs)
+
+	events, _ := parseTrace(t, buf)
+
+	// Now check that the stacks are correct.
+	type eventDesc struct {
+		Type byte
+		Stk  []frame
+	}
+	want := []eventDesc{
+		{trace.EvGCStart, []frame{
+			{"runtime.GC", 0},
+			{"runtime/trace_test.TestTraceSymbolize", 0},
+			{"testing.tRunner", 0},
+		}},
+		{trace.EvGoStart, []frame{
+			{"runtime/trace_test.TestTraceSymbolize.func1", 0},
+		}},
+		{trace.EvGoSched, []frame{
+			{"runtime/trace_test.TestTraceSymbolize", 111},
+			{"testing.tRunner", 0},
+		}},
+		{trace.EvGoCreate, []frame{
+			{"runtime/trace_test.TestTraceSymbolize", 40},
+			{"testing.tRunner", 0},
+		}},
+		{trace.EvGoStop, []frame{
+			{"runtime.block", 0},
+			{"runtime/trace_test.TestTraceSymbolize.func1", 0},
+		}},
+		{trace.EvGoStop, []frame{
+			{"runtime.chansend1", 0},
+			{"runtime/trace_test.TestTraceSymbolize.func2", 0},
+		}},
+		{trace.EvGoStop, []frame{
+			{"runtime.chanrecv1", 0},
+			{"runtime/trace_test.TestTraceSymbolize.func3", 0},
+		}},
+		{trace.EvGoBlockRecv, []frame{
+			{"runtime.chanrecv1", 0},
+			{"runtime/trace_test.TestTraceSymbolize.func4", 0},
+		}},
+		{trace.EvGoUnblock, []frame{
+			{"runtime.chansend1", 0},
+			{"runtime/trace_test.TestTraceSymbolize", 113},
+			{"testing.tRunner", 0},
+		}},
+		{trace.EvGoBlockSend, []frame{
+			{"runtime.chansend1", 0},
+			{"runtime/trace_test.TestTraceSymbolize.func5", 0},
+		}},
+		{trace.EvGoUnblock, []frame{
+			{"runtime.chanrecv1", 0},
+			{"runtime/trace_test.TestTraceSymbolize", 114},
+			{"testing.tRunner", 0},
+		}},
+		{trace.EvGoBlockSelect, []frame{
+			{"runtime.selectgo", 0},
+			{"runtime/trace_test.TestTraceSymbolize.func6", 0},
+		}},
+		{trace.EvGoUnblock, []frame{
+			{"runtime.selectgo", 0},
+			{"runtime/trace_test.TestTraceSymbolize", 115},
+			{"testing.tRunner", 0},
+		}},
+		{trace.EvGoBlockSync, []frame{
+			{"sync.(*Mutex).Lock", 0},
+			{"runtime/trace_test.TestTraceSymbolize.func7", 0},
+		}},
+		{trace.EvGoUnblock, []frame{
+			{"sync.(*Mutex).Unlock", 0},
+			{"runtime/trace_test.TestTraceSymbolize", 0},
+			{"testing.tRunner", 0},
+		}},
+		{trace.EvGoBlockSync, []frame{
+			{"sync.(*WaitGroup).Wait", 0},
+			{"runtime/trace_test.TestTraceSymbolize.func8", 0},
+		}},
+		{trace.EvGoUnblock, []frame{
+			{"sync.(*WaitGroup).Add", 0},
+			{"sync.(*WaitGroup).Done", 0},
+			{"runtime/trace_test.TestTraceSymbolize", 120},
+			{"testing.tRunner", 0},
+		}},
+		{trace.EvGoBlockCond, []frame{
+			{"sync.(*Cond).Wait", 0},
+			{"runtime/trace_test.TestTraceSymbolize.func9", 0},
+		}},
+		{trace.EvGoUnblock, []frame{
+			{"sync.(*Cond).Signal", 0},
+			{"runtime/trace_test.TestTraceSymbolize", 0},
+			{"testing.tRunner", 0},
+		}},
+		{trace.EvGoSleep, []frame{
+			{"time.Sleep", 0},
+			{"runtime/trace_test.TestTraceSymbolize", 0},
+			{"testing.tRunner", 0},
+		}},
+		{trace.EvGomaxprocs, []frame{
+			{"runtime.startTheWorld", 0}, // this is when the current gomaxprocs is logged.
+			{"runtime.startTheWorldGC", 0},
+			{"runtime.GOMAXPROCS", 0},
+			{"runtime/trace_test.TestTraceSymbolize", 0},
+			{"testing.tRunner", 0},
+		}},
+	}
+	// Stacks for the following events are OS-dependent due to OS-specific code in net package.
+	if runtime.GOOS != "windows" && runtime.GOOS != "plan9" {
+		want = append(want, []eventDesc{
+			{trace.EvGoBlockNet, []frame{
+				{"internal/poll.(*FD).Accept", 0},
+				{"net.(*netFD).accept", 0},
+				{"net.(*TCPListener).accept", 0},
+				{"net.(*TCPListener).Accept", 0},
+				{"runtime/trace_test.TestTraceSymbolize.func10", 0},
+			}},
+			{trace.EvGoSysCall, []frame{
+				{"syscall.read", 0},
+				{"syscall.Read", 0},
+				{"internal/poll.ignoringEINTRIO", 0},
+				{"internal/poll.(*FD).Read", 0},
+				{"os.(*File).read", 0},
+				{"os.(*File).Read", 0},
+				{"runtime/trace_test.TestTraceSymbolize.func11", 0},
+			}},
+		}...)
+	}
+	matched := make([]bool, len(want))
+	for _, ev := range events {
+	wantLoop:
+		for i, w := range want {
+			if matched[i] || w.Type != ev.Type || len(w.Stk) != len(ev.Stk) {
+				continue
+			}
+
+			for fi, f := range ev.Stk {
+				wf := w.Stk[fi]
+				if wf.Fn != f.Fn || wf.Line != 0 && wf.Line != f.Line {
+					continue wantLoop
+				}
+			}
+			matched[i] = true
+		}
+	}
+	for i, w := range want {
+		if matched[i] {
+			continue
+		}
+		seen, n := dumpEventStacks(w.Type, events)
+		t.Errorf("Did not match event %v with stack\n%s\nSeen %d events of the type\n%s",
+			trace.EventDescriptions[w.Type].Name, dumpFrames(w.Stk), n, seen)
+	}
+}
+
+func skipTraceSymbolizeTestIfNecessary(t *testing.T) {
+	testenv.MustHaveGoBuild(t)
+	if IsEnabled() {
+		t.Skip("skipping because -test.trace is set")
+	}
+}
+
+func dumpEventStacks(typ byte, events []*trace.Event) ([]byte, int) {
+	matched := 0
+	o := new(bytes.Buffer)
+	tw := tabwriter.NewWriter(o, 0, 8, 0, '\t', 0)
+	for _, ev := range events {
+		if ev.Type != typ {
+			continue
+		}
+		matched++
+		fmt.Fprintf(tw, "Offset %d\n", ev.Off)
+		for _, f := range ev.Stk {
+			fname := f.File
+			if idx := strings.Index(fname, "/go/src/"); idx > 0 {
+				fname = fname[idx:]
+			}
+			fmt.Fprintf(tw, "  %v\t%s:%d\n", f.Fn, fname, f.Line)
+		}
+	}
+	tw.Flush()
+	return o.Bytes(), matched
+}
+
+type frame struct {
+	Fn   string
+	Line int
+}
+
+func dumpFrames(frames []frame) []byte {
+	o := new(bytes.Buffer)
+	tw := tabwriter.NewWriter(o, 0, 8, 0, '\t', 0)
+
+	for _, f := range frames {
+		fmt.Fprintf(tw, "  %v\t :%d\n", f.Fn, f.Line)
+	}
+	tw.Flush()
+	return o.Bytes()
+}