1 files changed, 452 insertions, 0 deletions
diff --git a/src/runtime/pprof/pprof_test.go b/src/runtime/pprof/pprof_test.go
new file mode 100644
index 000000000..8677cb30c
--- /dev/null
+++ b/src/runtime/pprof/pprof_test.go
@@ -0,0 +1,452 @@
+// Copyright 2011 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.
+
+// +build !nacl
+
+package pprof_test
+
+import (
+	"bytes"
+	"fmt"
+	"math/big"
+	"os/exec"
+	"regexp"
+	"runtime"
+	. "runtime/pprof"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+	"unsafe"
+)
+
+func cpuHogger(f func()) {
+	// We only need to get one 100 Hz clock tick, so we've got
+	// a 25x safety buffer.
+	// But do at least 500 iterations (which should take about 100ms),
+	// otherwise TestCPUProfileMultithreaded can fail if only one
+	// thread is scheduled during the 250ms period.
+	t0 := time.Now()
+	for i := 0; i < 500 || time.Since(t0) < 250*time.Millisecond; i++ {
+		f()
+	}
+}
+
+var (
+	salt1 = 0
+	salt2 = 0
+)
+
+// The actual CPU hogging function.
+// Must not call other functions nor access heap/globals in the loop,
+// otherwise under race detector the samples will be in the race runtime.
+func cpuHog1() {
+	foo := salt1
+	for i := 0; i < 1e5; i++ {
+		if foo > 0 {
+			foo *= foo
+		} else {
+			foo *= foo + 1
+		}
+	}
+	salt1 = foo
+}
+
+func cpuHog2() {
+	foo := salt2
+	for i := 0; i < 1e5; i++ {
+		if foo > 0 {
+			foo *= foo
+		} else {
+			foo *= foo + 2
+		}
+	}
+	salt2 = foo
+}
+
+func TestCPUProfile(t *testing.T) {
+	testCPUProfile(t, []string{"runtime/pprof_test.cpuHog1"}, func() {
+		cpuHogger(cpuHog1)
+	})
+}
+
+func TestCPUProfileMultithreaded(t *testing.T) {
+	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(2))
+	testCPUProfile(t, []string{"runtime/pprof_test.cpuHog1", "runtime/pprof_test.cpuHog2"}, func() {
+		c := make(chan int)
+		go func() {
+			cpuHogger(cpuHog1)
+			c <- 1
+		}()
+		cpuHogger(cpuHog2)
+		<-c
+	})
+}
+
+func parseProfile(t *testing.T, bytes []byte, f func(uintptr, []uintptr)) {
+	// Convert []byte to []uintptr.
+	l := len(bytes) / int(unsafe.Sizeof(uintptr(0)))
+	val := *(*[]uintptr)(unsafe.Pointer(&bytes))
+	val = val[:l]
+
+	// 5 for the header, 2 for the per-sample header on at least one sample, 3 for the trailer.
+	if l < 5+2+3 {
+		t.Logf("profile too short: %#x", val)
+		if badOS[runtime.GOOS] {
+			t.Skipf("ignoring failure on %s; see golang.org/issue/6047", runtime.GOOS)
+			return
+		}
+		t.FailNow()
+	}
+
+	hd, val, tl := val[:5], val[5:l-3], val[l-3:]
+	if hd[0] != 0 || hd[1] != 3 || hd[2] != 0 || hd[3] != 1e6/100 || hd[4] != 0 {
+		t.Fatalf("unexpected header %#x", hd)
+	}
+
+	if tl[0] != 0 || tl[1] != 1 || tl[2] != 0 {
+		t.Fatalf("malformed end-of-data marker %#x", tl)
+	}
+
+	for len(val) > 0 {
+		if len(val) < 2 || val[0] < 1 || val[1] < 1 || uintptr(len(val)) < 2+val[1] {
+			t.Fatalf("malformed profile.  leftover: %#x", val)
+		}
+		f(val[0], val[2:2+val[1]])
+		val = val[2+val[1]:]
+	}
+}
+
+func testCPUProfile(t *testing.T, need []string, f func()) {
+	switch runtime.GOOS {
+	case "darwin":
+		out, err := exec.Command("uname", "-a").CombinedOutput()
+		if err != nil {
+			t.Fatal(err)
+		}
+		vers := string(out)
+		t.Logf("uname -a: %v", vers)
+	case "plan9":
+		// unimplemented
+		return
+	}
+
+	var prof bytes.Buffer
+	if err := StartCPUProfile(&prof); err != nil {
+		t.Fatal(err)
+	}
+	f()
+	StopCPUProfile()
+
+	// Check that profile is well formed and contains need.
+	have := make([]uintptr, len(need))
+	parseProfile(t, prof.Bytes(), func(count uintptr, stk []uintptr) {
+		for _, pc := range stk {
+			f := runtime.FuncForPC(pc)
+			if f == nil {
+				continue
+			}
+			for i, name := range need {
+				if strings.Contains(f.Name(), name) {
+					have[i] += count
+				}
+			}
+		}
+	})
+
+	if len(need) == 0 {
+		return
+	}
+
+	var total uintptr
+	for i, name := range need {
+		total += have[i]
+		t.Logf("%s: %d\n", name, have[i])
+	}
+	ok := true
+	if total == 0 {
+		t.Logf("no CPU profile samples collected")
+		ok = false
+	}
+	// We'd like to check a reasonable minimum, like
+	// total / len(have) / smallconstant, but this test is
+	// pretty flaky (see bug 7095).  So we'll just test to
+	// make sure we got at least one sample.
+	min := uintptr(1)
+	for i, name := range need {
+		if have[i] < min {
+			t.Logf("%s has %d samples out of %d, want at least %d, ideally %d", name, have[i], total, min, total/uintptr(len(have)))
+			ok = false
+		}
+	}
+
+	if !ok {
+		if badOS[runtime.GOOS] {
+			t.Skipf("ignoring failure on %s; see golang.org/issue/6047", runtime.GOOS)
+			return
+		}
+		t.FailNow()
+	}
+}
+
+func TestCPUProfileWithFork(t *testing.T) {
+	// Fork can hang if preempted with signals frequently enough (see issue 5517).
+	// Ensure that we do not do this.
+	heap := 1 << 30
+	if testing.Short() {
+		heap = 100 << 20
+	}
+	// This makes fork slower.
+	garbage := make([]byte, heap)
+	// Need to touch the slice, otherwise it won't be paged in.
+	done := make(chan bool)
+	go func() {
+		for i := range garbage {
+			garbage[i] = 42
+		}
+		done <- true
+	}()
+	<-done
+
+	var prof bytes.Buffer
+	if err := StartCPUProfile(&prof); err != nil {
+		t.Fatal(err)
+	}
+	defer StopCPUProfile()
+
+	for i := 0; i < 10; i++ {
+		exec.Command("go").CombinedOutput()
+	}
+}
+
+// Test that profiler does not observe runtime.gogo as "user" goroutine execution.
+// If it did, it would see inconsistent state and would either record an incorrect stack
+// or crash because the stack was malformed.
+func TestGoroutineSwitch(t *testing.T) {
+	// How much to try. These defaults take about 1 seconds
+	// on a 2012 MacBook Pro. The ones in short mode take
+	// about 0.1 seconds.
+	tries := 10
+	count := 1000000
+	if testing.Short() {
+		tries = 1
+	}
+	for try := 0; try < tries; try++ {
+		var prof bytes.Buffer
+		if err := StartCPUProfile(&prof); err != nil {
+			t.Fatal(err)
+		}
+		for i := 0; i < count; i++ {
+			runtime.Gosched()
+		}
+		StopCPUProfile()
+
+		// Read profile to look for entries for runtime.gogo with an attempt at a traceback.
+		// The special entry
+		parseProfile(t, prof.Bytes(), func(count uintptr, stk []uintptr) {
+			// An entry with two frames with 'System' in its top frame
+			// exists to record a PC without a traceback. Those are okay.
+			if len(stk) == 2 {
+				f := runtime.FuncForPC(stk[1])
+				if f != nil && (f.Name() == "System" || f.Name() == "ExternalCode" || f.Name() == "GC") {
+					return
+				}
+			}
+
+			// Otherwise, should not see runtime.gogo.
+			// The place we'd see it would be the inner most frame.
+			f := runtime.FuncForPC(stk[0])
+			if f != nil && f.Name() == "runtime.gogo" {
+				var buf bytes.Buffer
+				for _, pc := range stk {
+					f := runtime.FuncForPC(pc)
+					if f == nil {
+						fmt.Fprintf(&buf, "%#x ?:0\n", pc)
+					} else {
+						file, line := f.FileLine(pc)
+						fmt.Fprintf(&buf, "%#x %s:%d\n", pc, file, line)
+					}
+				}
+				t.Fatalf("found profile entry for runtime.gogo:\n%s", buf.String())
+			}
+		})
+	}
+}
+
+// Test that profiling of division operations is okay, especially on ARM. See issue 6681.
+func TestMathBigDivide(t *testing.T) {
+	testCPUProfile(t, nil, func() {
+		t := time.After(5 * time.Second)
+		pi := new(big.Int)
+		for {
+			for i := 0; i < 100; i++ {
+				n := big.NewInt(2646693125139304345)
+				d := big.NewInt(842468587426513207)
+				pi.Div(n, d)
+			}
+			select {
+			case <-t:
+				return
+			default:
+			}
+		}
+	})
+}
+
+// Operating systems that are expected to fail the tests. See issue 6047.
+var badOS = map[string]bool{
+	"darwin": true,
+	"netbsd": true,
+	"plan9":  true,
+}
+
+func TestBlockProfile(t *testing.T) {
+	type TestCase struct {
+		name string
+		f    func()
+		re   string
+	}
+	tests := [...]TestCase{
+		{"chan recv", blockChanRecv, `
+[0-9]+ [0-9]+ @ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+
+#	0x[0-9,a-f]+	runtime\.chanrecv1\+0x[0-9,a-f]+	.*/src/runtime/chan.go:[0-9]+
+#	0x[0-9,a-f]+	runtime/pprof_test\.blockChanRecv\+0x[0-9,a-f]+	.*/src/runtime/pprof/pprof_test.go:[0-9]+
+#	0x[0-9,a-f]+	runtime/pprof_test\.TestBlockProfile\+0x[0-9,a-f]+	.*/src/runtime/pprof/pprof_test.go:[0-9]+
+`},
+		{"chan send", blockChanSend, `
+[0-9]+ [0-9]+ @ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+
+#	0x[0-9,a-f]+	runtime\.chansend1\+0x[0-9,a-f]+	.*/src/runtime/chan.go:[0-9]+
+#	0x[0-9,a-f]+	runtime/pprof_test\.blockChanSend\+0x[0-9,a-f]+	.*/src/runtime/pprof/pprof_test.go:[0-9]+
+#	0x[0-9,a-f]+	runtime/pprof_test\.TestBlockProfile\+0x[0-9,a-f]+	.*/src/runtime/pprof/pprof_test.go:[0-9]+
+`},
+		{"chan close", blockChanClose, `
+[0-9]+ [0-9]+ @ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+
+#	0x[0-9,a-f]+	runtime\.chanrecv1\+0x[0-9,a-f]+	.*/src/runtime/chan.go:[0-9]+
+#	0x[0-9,a-f]+	runtime/pprof_test\.blockChanClose\+0x[0-9,a-f]+	.*/src/runtime/pprof/pprof_test.go:[0-9]+
+#	0x[0-9,a-f]+	runtime/pprof_test\.TestBlockProfile\+0x[0-9,a-f]+	.*/src/runtime/pprof/pprof_test.go:[0-9]+
+`},
+		{"select recv async", blockSelectRecvAsync, `
+[0-9]+ [0-9]+ @ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+
+#	0x[0-9,a-f]+	runtime\.selectgo\+0x[0-9,a-f]+	.*/src/runtime/select.go:[0-9]+
+#	0x[0-9,a-f]+	runtime/pprof_test\.blockSelectRecvAsync\+0x[0-9,a-f]+	.*/src/runtime/pprof/pprof_test.go:[0-9]+
+#	0x[0-9,a-f]+	runtime/pprof_test\.TestBlockProfile\+0x[0-9,a-f]+	.*/src/runtime/pprof/pprof_test.go:[0-9]+
+`},
+		{"select send sync", blockSelectSendSync, `
+[0-9]+ [0-9]+ @ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+
+#	0x[0-9,a-f]+	runtime\.selectgo\+0x[0-9,a-f]+	.*/src/runtime/select.go:[0-9]+
+#	0x[0-9,a-f]+	runtime/pprof_test\.blockSelectSendSync\+0x[0-9,a-f]+	.*/src/runtime/pprof/pprof_test.go:[0-9]+
+#	0x[0-9,a-f]+	runtime/pprof_test\.TestBlockProfile\+0x[0-9,a-f]+	.*/src/runtime/pprof/pprof_test.go:[0-9]+
+`},
+		{"mutex", blockMutex, `
+[0-9]+ [0-9]+ @ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+
+#	0x[0-9,a-f]+	sync\.\(\*Mutex\)\.Lock\+0x[0-9,a-f]+	.*/src/sync/mutex\.go:[0-9]+
+#	0x[0-9,a-f]+	runtime/pprof_test\.blockMutex\+0x[0-9,a-f]+	.*/src/runtime/pprof/pprof_test.go:[0-9]+
+#	0x[0-9,a-f]+	runtime/pprof_test\.TestBlockProfile\+0x[0-9,a-f]+	.*/src/runtime/pprof/pprof_test.go:[0-9]+
+`},
+		{"cond", blockCond, `
+[0-9]+ [0-9]+ @ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+ 0x[0-9,a-f]+
+#	0x[0-9,a-f]+	sync\.\(\*Cond\)\.Wait\+0x[0-9,a-f]+	.*/src/sync/cond\.go:[0-9]+
+#	0x[0-9,a-f]+	runtime/pprof_test\.blockCond\+0x[0-9,a-f]+	.*/src/runtime/pprof/pprof_test.go:[0-9]+
+#	0x[0-9,a-f]+	runtime/pprof_test\.TestBlockProfile\+0x[0-9,a-f]+	.*/src/runtime/pprof/pprof_test.go:[0-9]+
+`},
+	}
+
+	runtime.SetBlockProfileRate(1)
+	defer runtime.SetBlockProfileRate(0)
+	for _, test := range tests {
+		test.f()
+	}
+	var w bytes.Buffer
+	Lookup("block").WriteTo(&w, 1)
+	prof := w.String()
+
+	if !strings.HasPrefix(prof, "--- contention:\ncycles/second=") {
+		t.Fatalf("Bad profile header:\n%v", prof)
+	}
+
+	for _, test := range tests {
+		if !regexp.MustCompile(test.re).MatchString(prof) {
+			t.Fatalf("Bad %v entry, expect:\n%v\ngot:\n%v", test.name, test.re, prof)
+		}
+	}
+}
+
+const blockDelay = 10 * time.Millisecond
+
+func blockChanRecv() {
+	c := make(chan bool)
+	go func() {
+		time.Sleep(blockDelay)
+		c <- true
+	}()
+	<-c
+}
+
+func blockChanSend() {
+	c := make(chan bool)
+	go func() {
+		time.Sleep(blockDelay)
+		<-c
+	}()
+	c <- true
+}
+
+func blockChanClose() {
+	c := make(chan bool)
+	go func() {
+		time.Sleep(blockDelay)
+		close(c)
+	}()
+	<-c
+}
+
+func blockSelectRecvAsync() {
+	c := make(chan bool, 1)
+	c2 := make(chan bool, 1)
+	go func() {
+		time.Sleep(blockDelay)
+		c <- true
+	}()
+	select {
+	case <-c:
+	case <-c2:
+	}
+}
+
+func blockSelectSendSync() {
+	c := make(chan bool)
+	c2 := make(chan bool)
+	go func() {
+		time.Sleep(blockDelay)
+		<-c
+	}()
+	select {
+	case c <- true:
+	case c2 <- true:
+	}
+}
+
+func blockMutex() {
+	var mu sync.Mutex
+	mu.Lock()
+	go func() {
+		time.Sleep(blockDelay)
+		mu.Unlock()
+	}()
+	mu.Lock()
+}
+
+func blockCond() {
+	var mu sync.Mutex
+	c := sync.NewCond(&mu)
+	mu.Lock()
+	go func() {
+		time.Sleep(blockDelay)
+		mu.Lock()
+		c.Signal()
+		mu.Unlock()
+	}()
+	c.Wait()
+	mu.Unlock()
+}