go pprof_test 源码
golang pprof_test 代码
文件路径：/src/runtime/pprof/pprof_test.go
// 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.
//go:build !js
package pprof
import (
"bytes"
"context"
"fmt"
"internal/abi"
"internal/profile"
"internal/testenv"
"io"
"math"
"math/big"
"os"
"os/exec"
"regexp"
"runtime"
"runtime/debug"
"strings"
"sync"
"sync/atomic"
"testing"
"time"
_ "unsafe"
)
func cpuHogger(f func(x int) int, y *int, dur time.Duration) {
// We only need to get one 100 Hz clock tick, so we've got
// a large 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 testing period.
t0 := time.Now()
accum := *y
for i := 0; i < 500 || time.Since(t0) < dur; i++ {
accum = f(accum)
}
*y = accum
}
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(x int) int {
return cpuHog0(x, 1e5)
}
func cpuHog0(x, n int) int {
foo := x
for i := 0; i < n; i++ {
if foo > 0 {
foo *= foo
} else {
foo *= foo + 1
}
}
return foo
}
func cpuHog2(x int) int {
foo := x
for i := 0; i < 1e5; i++ {
if foo > 0 {
foo *= foo
} else {
foo *= foo + 2
}
}
return foo
}
// Return a list of functions that we don't want to ever appear in CPU
// profiles. For gccgo, that list includes the sigprof handler itself.
func avoidFunctions() []string {
if runtime.Compiler == "gccgo" {
return []string{"runtime.sigprof"}
}
return nil
}
func TestCPUProfile(t *testing.T) {
matches := matchAndAvoidStacks(stackContains, []string{"runtime/pprof.cpuHog1"}, avoidFunctions())
testCPUProfile(t, matches, func(dur time.Duration) {
cpuHogger(cpuHog1, &salt1, dur)
})
}
func TestCPUProfileMultithreaded(t *testing.T) {
defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(2))
matches := matchAndAvoidStacks(stackContains, []string{"runtime/pprof.cpuHog1", "runtime/pprof.cpuHog2"}, avoidFunctions())
testCPUProfile(t, matches, func(dur time.Duration) {
c := make(chan int)
go func() {
cpuHogger(cpuHog1, &salt1, dur)
c <- 1
}()
cpuHogger(cpuHog2, &salt2, dur)
<-c
})
}
func TestCPUProfileMultithreadMagnitude(t *testing.T) {
if runtime.GOOS != "linux" {
t.Skip("issue 35057 is only confirmed on Linux")
}
// Linux [5.9,5.16) has a kernel bug that can break CPU timers on newly
// created threads, breaking our CPU accounting.
major, minor, patch, err := linuxKernelVersion()
if err != nil {
t.Errorf("Error determining kernel version: %v", err)
}
t.Logf("Running on Linux %d.%d.%d", major, minor, patch)
defer func() {
if t.Failed() {
t.Logf("Failure of this test may indicate that your system suffers from a known Linux kernel bug fixed on newer kernels. See https://golang.org/issue/49065.")
}
}()
// Disable on affected builders to avoid flakiness, but otherwise keep
// it enabled to potentially warn users that they are on a broken
// kernel.
if testenv.Builder() != "" && (runtime.GOARCH == "386" || runtime.GOARCH == "amd64") {
have59 := major > 5 || (major == 5 && minor >= 9)
have516 := major > 5 || (major == 5 && minor >= 16)
if have59 && !have516 {
testenv.SkipFlaky(t, 49065)
}
}
// Run a workload in a single goroutine, then run copies of the same
// workload in several goroutines. For both the serial and parallel cases,
// the CPU time the process measures with its own profiler should match the
// total CPU usage that the OS reports.
//
// We could also check that increases in parallelism (GOMAXPROCS) lead to a
// linear increase in the CPU usage reported by both the OS and the
// profiler, but without a guarantee of exclusive access to CPU resources
// that is likely to be a flaky test.
// Require the smaller value to be within 10%, or 40% in short mode.
maxDiff := 0.10
if testing.Short() {
maxDiff = 0.40
}
compare := func(a, b time.Duration, maxDiff float64) error {
if a <= 0 || b <= 0 {
return fmt.Errorf("Expected both time reports to be positive")
}
if a < b {
a, b = b, a
}
diff := float64(a-b) / float64(a)
if diff > maxDiff {
return fmt.Errorf("CPU usage reports are too different (limit -%.1f%%, got -%.1f%%)", maxDiff*100, diff*100)
}
return nil
}
for _, tc := range []struct {
name string
workers int
}{
{
name: "serial",
workers: 1,
},
{
name: "parallel",
workers: runtime.GOMAXPROCS(0),
},
} {
// check that the OS's perspective matches what the Go runtime measures.
t.Run(tc.name, func(t *testing.T) {
t.Logf("Running with %d workers", tc.workers)
var userTime, systemTime time.Duration
matches := matchAndAvoidStacks(stackContains, []string{"runtime/pprof.cpuHog1"}, avoidFunctions())
acceptProfile := func(t *testing.T, p *profile.Profile) bool {
if !matches(t, p) {
return false
}
ok := true
for i, unit := range []string{"count", "nanoseconds"} {
if have, want := p.SampleType[i].Unit, unit; have != want {
t.Logf("pN SampleType[%d]; %q != %q", i, have, want)
ok = false
}
}
// cpuHog1 called below is the primary source of CPU
// load, but there may be some background work by the
// runtime. Since the OS rusage measurement will
// include all work done by the process, also compare
// against all samples in our profile.
var value time.Duration
for _, sample := range p.Sample {
value += time.Duration(sample.Value[1]) * time.Nanosecond
}
totalTime := userTime + systemTime
t.Logf("compare %s user + %s system = %s vs %s", userTime, systemTime, totalTime, value)
if err := compare(totalTime, value, maxDiff); err != nil {
t.Logf("compare got %v want nil", err)
ok = false
}
return ok
}
testCPUProfile(t, acceptProfile, func(dur time.Duration) {
userTime, systemTime = diffCPUTime(t, func() {
var wg sync.WaitGroup
var once sync.Once
for i := 0; i < tc.workers; i++ {
wg.Add(1)
go func() {
defer wg.Done()
var salt = 0
cpuHogger(cpuHog1, &salt, dur)
once.Do(func() { salt1 = salt })
}()
}
wg.Wait()
})
})
})
}
}
// containsInlinedCall reports whether the function body for the function f is
// known to contain an inlined function call within the first maxBytes bytes.
func containsInlinedCall(f any, maxBytes int) bool {
_, found := findInlinedCall(f, maxBytes)
return found
}
// findInlinedCall returns the PC of an inlined function call within
// the function body for the function f if any.
func findInlinedCall(f any, maxBytes int) (pc uint64, found bool) {
fFunc := runtime.FuncForPC(uintptr(abi.FuncPCABIInternal(f)))
if fFunc == nil || fFunc.Entry() == 0 {
panic("failed to locate function entry")
}
for offset := 0; offset < maxBytes; offset++ {
innerPC := fFunc.Entry() + uintptr(offset)
inner := runtime.FuncForPC(innerPC)
if inner == nil {
// No function known for this PC value.
// It might simply be misaligned, so keep searching.
continue
}
if inner.Entry() != fFunc.Entry() {
// Scanned past f and didn't find any inlined functions.
break
}
if inner.Name() != fFunc.Name() {
// This PC has f as its entry-point, but is not f. Therefore, it must be a
// function inlined into f.
return uint64(innerPC), true
}
}
return 0, false
}
func TestCPUProfileInlining(t *testing.T) {
if !containsInlinedCall(inlinedCaller, 4<<10) {
t.Skip("Can't determine whether inlinedCallee was inlined into inlinedCaller.")
}
matches := matchAndAvoidStacks(stackContains, []string{"runtime/pprof.inlinedCallee", "runtime/pprof.inlinedCaller"}, avoidFunctions())
p := testCPUProfile(t, matches, func(dur time.Duration) {
cpuHogger(inlinedCaller, &salt1, dur)
})
// Check if inlined function locations are encoded correctly. The inlinedCalee and inlinedCaller should be in one location.
for _, loc := range p.Location {
hasInlinedCallerAfterInlinedCallee, hasInlinedCallee := false, false
for _, line := range loc.Line {
if line.Function.Name == "runtime/pprof.inlinedCallee" {
hasInlinedCallee = true
}
if hasInlinedCallee && line.Function.Name == "runtime/pprof.inlinedCaller" {
hasInlinedCallerAfterInlinedCallee = true
}
}
if hasInlinedCallee != hasInlinedCallerAfterInlinedCallee {
t.Fatalf("want inlinedCallee followed by inlinedCaller, got separate Location entries:\n%v", p)
}
}
}
func inlinedCaller(x int) int {
x = inlinedCallee(x, 1e5)
return x
}
func inlinedCallee(x, n int) int {
return cpuHog0(x, n)
}
//go:noinline
func dumpCallers(pcs []uintptr) {
if pcs == nil {
return
}
skip := 2 // Callers and dumpCallers
runtime.Callers(skip, pcs)
}
//go:noinline
func inlinedCallerDump(pcs []uintptr) {
inlinedCalleeDump(pcs)
}
func inlinedCalleeDump(pcs []uintptr) {
dumpCallers(pcs)
}
func TestCPUProfileRecursion(t *testing.T) {
matches := matchAndAvoidStacks(stackContains, []string{"runtime/pprof.inlinedCallee", "runtime/pprof.recursionCallee", "runtime/pprof.recursionCaller"}, avoidFunctions())
p := testCPUProfile(t, matches, func(dur time.Duration) {
cpuHogger(recursionCaller, &salt1, dur)
})
// check the Location encoding was not confused by recursive calls.
for i, loc := range p.Location {
recursionFunc := 0
for _, line := range loc.Line {
if name := line.Function.Name; name == "runtime/pprof.recursionCaller" || name == "runtime/pprof.recursionCallee" {
recursionFunc++
}
}
if recursionFunc > 1 {
t.Fatalf("want at most one recursionCaller or recursionCallee in one Location, got a violating Location (index: %d):\n%v", i, p)
}
}
}
func recursionCaller(x int) int {
y := recursionCallee(3, x)
return y
}
func recursionCallee(n, x int) int {
if n == 0 {
return 1
}
y := inlinedCallee(x, 1e4)
return y * recursionCallee(n-1, x)
}
func recursionChainTop(x int, pcs []uintptr) {
if x < 0 {
return
}
recursionChainMiddle(x, pcs)
}
func recursionChainMiddle(x int, pcs []uintptr) {
recursionChainBottom(x, pcs)
}
func recursionChainBottom(x int, pcs []uintptr) {
// This will be called each time, we only care about the last. We
// can't make this conditional or this function won't be inlined.
dumpCallers(pcs)
recursionChainTop(x-1, pcs)
}
func parseProfile(t *testing.T, valBytes []byte, f func(uintptr, []*profile.Location, map[string][]string)) *profile.Profile {
p, err := profile.Parse(bytes.NewReader(valBytes))
if err != nil {
t.Fatal(err)
}
for _, sample := range p.Sample {
count := uintptr(sample.Value[0])
f(count, sample.Location, sample.Label)
}
return p
}
func cpuProfilingBroken() bool {
switch runtime.GOOS {
case "plan9":
// Profiling unimplemented.
return true
case "aix":
// See https://golang.org/issue/45170.
return true
case "ios", "dragonfly", "netbsd", "illumos", "solaris":
// See https://golang.org/issue/13841.
return true
case "openbsd":
if runtime.GOARCH == "arm" || runtime.GOARCH == "arm64" {
// See https://golang.org/issue/13841.
return true
}
}
return false
}
// testCPUProfile runs f under the CPU profiler, checking for some conditions specified by need,
// as interpreted by matches, and returns the parsed profile.
func testCPUProfile(t *testing.T, matches profileMatchFunc, f func(dur time.Duration)) *profile.Profile {
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":
t.Skip("skipping on plan9")
}
broken := cpuProfilingBroken()
deadline, ok := t.Deadline()
if broken || !ok {
if broken && testing.Short() {
// If it's expected to be broken, no point waiting around.
deadline = time.Now().Add(1 * time.Second)
} else {
deadline = time.Now().Add(10 * time.Second)
}
}
// If we're running a long test, start with a long duration
// for tests that try to make sure something *doesn't* happen.
duration := 5 * time.Second
if testing.Short() {
duration = 100 * time.Millisecond
}
// Profiling tests are inherently flaky, especially on a
// loaded system, such as when this test is running with
// several others under go test std. If a test fails in a way
// that could mean it just didn't run long enough, try with a
// longer duration.
for {
var prof bytes.Buffer
if err := StartCPUProfile(&prof); err != nil {
t.Fatal(err)
}
f(duration)
StopCPUProfile()
if p, ok := profileOk(t, matches, prof, duration); ok {
return p
}
duration *= 2
if time.Until(deadline) < duration {
break
}
t.Logf("retrying with %s duration", duration)
}
if broken {
t.Skipf("ignoring failure on %s/%s; see golang.org/issue/13841", runtime.GOOS, runtime.GOARCH)
}
// Ignore the failure if the tests are running in a QEMU-based emulator,
// QEMU is not perfect at emulating everything.
// IN_QEMU environmental variable is set by some of the Go builders.
// IN_QEMU=1 indicates that the tests are running in QEMU. See issue 9605.
if os.Getenv("IN_QEMU") == "1" {
t.Skip("ignore the failure in QEMU; see golang.org/issue/9605")
}
t.FailNow()
return nil
}
var diffCPUTimeImpl func(f func()) (user, system time.Duration)
func diffCPUTime(t *testing.T, f func()) (user, system time.Duration) {
if fn := diffCPUTimeImpl; fn != nil {
return fn(f)
}
t.Fatalf("cannot measure CPU time on GOOS=%s GOARCH=%s", runtime.GOOS, runtime.GOARCH)
return 0, 0
}
func contains(slice []string, s string) bool {
for i := range slice {
if slice[i] == s {
return true
}
}
return false
}
// stackContains matches if a function named spec appears anywhere in the stack trace.
func stackContains(spec string, count uintptr, stk []*profile.Location, labels map[string][]string) bool {
for _, loc := range stk {
for _, line := range loc.Line {
if strings.Contains(line.Function.Name, spec) {
return true
}
}
}
return false
}
type sampleMatchFunc func(spec string, count uintptr, stk []*profile.Location, labels map[string][]string) bool
func profileOk(t *testing.T, matches profileMatchFunc, prof bytes.Buffer, duration time.Duration) (_ *profile.Profile, ok bool) {
ok = true
var samples uintptr
var buf bytes.Buffer
p := parseProfile(t, prof.Bytes(), func(count uintptr, stk []*profile.Location, labels map[string][]string) {
fmt.Fprintf(&buf, "%d:", count)
fprintStack(&buf, stk)
fmt.Fprintf(&buf, " labels: %v\n", labels)
samples += count
fmt.Fprintf(&buf, "\n")
})
t.Logf("total %d CPU profile samples collected:\n%s", samples, buf.String())
if samples < 10 && runtime.GOOS == "windows" {
// On some windows machines we end up with
// not enough samples due to coarse timer
// resolution. Let it go.
t.Log("too few samples on Windows (golang.org/issue/10842)")
return p, false
}
// Check that we got a reasonable number of samples.
// We used to always require at least ideal/4 samples,
// but that is too hard to guarantee on a loaded system.
// Now we accept 10 or more samples, which we take to be
// enough to show that at least some profiling is occurring.
if ideal := uintptr(duration * 100 / time.Second); samples == 0 || (samples < ideal/4 && samples < 10) {
t.Logf("too few samples; got %d, want at least %d, ideally %d", samples, ideal/4, ideal)
ok = false
}
if matches != nil && !matches(t, p) {
ok = false
}
return p, ok
}
type profileMatchFunc func(*testing.T, *profile.Profile) bool
func matchAndAvoidStacks(matches sampleMatchFunc, need []string, avoid []string) profileMatchFunc {
return func(t *testing.T, p *profile.Profile) (ok bool) {
ok = true
// Check that profile is well formed, contains 'need', and does not contain
// anything from 'avoid'.
have := make([]uintptr, len(need))
avoidSamples := make([]uintptr, len(avoid))
for _, sample := range p.Sample {
count := uintptr(sample.Value[0])
for i, spec := range need {
if matches(spec, count, sample.Location, sample.Label) {
have[i] += count
}
}
for i, name := range avoid {
for _, loc := range sample.Location {
for _, line := range loc.Line {
if strings.Contains(line.Function.Name, name) {
avoidSamples[i] += count
}
}
}
}
}
for i, name := range avoid {
bad := avoidSamples[i]
if bad != 0 {
t.Logf("found %d samples in avoid-function %s\n", bad, name)
ok = false
}
}
if len(need) == 0 {
return
}
var total uintptr
for i, name := range need {
total += have[i]
t.Logf("%s: %d\n", name, have[i])
}
if total == 0 {
t.Logf("no samples in expected functions")
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
}
}
return
}
}
// Fork can hang if preempted with signals frequently enough (see issue 5517).
// Ensure that we do not do this.
func TestCPUProfileWithFork(t *testing.T) {
testenv.MustHaveExec(t)
heap := 1 << 30
if runtime.GOOS == "android" {
// Use smaller size for Android to avoid crash.
heap = 100 << 20
}
if runtime.GOOS == "windows" && runtime.GOARCH == "arm" {
// Use smaller heap for Windows/ARM to avoid crash.
heap = 100 << 20
}
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(os.Args[0], "-h").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) {
if runtime.Compiler == "gccgo" {
t.Skip("not applicable for gccgo")
}
// 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 gogo with an attempt at a traceback.
// "runtime.gogo" is OK, because that's the part of the context switch
// before the actual switch begins. But we should not see "gogo",
// aka "gogo<>(SB)", which does the actual switch and is marked SPWRITE.
parseProfile(t, prof.Bytes(), func(count uintptr, stk []*profile.Location, _ map[string][]string) {
// 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 {
name := stk[1].Line[0].Function.Name
if name == "runtime._System" || name == "runtime._ExternalCode" || name == "runtime._GC" {
return
}
}
// An entry with just one frame is OK too:
// it knew to stop at gogo.
if len(stk) == 1 {
return
}
// Otherwise, should not see gogo.
// The place we'd see it would be the inner most frame.
name := stk[0].Line[0].Function.Name
if name == "gogo" {
var buf bytes.Buffer
fprintStack(&buf, stk)
t.Fatalf("found profile entry for gogo:\n%s", buf.String())
}
})
}
}
func fprintStack(w io.Writer, stk []*profile.Location) {
for _, loc := range stk {
fmt.Fprintf(w, " %#x", loc.Address)
fmt.Fprintf(w, " (")
for i, line := range loc.Line {
if i > 0 {
fmt.Fprintf(w, " ")
}
fmt.Fprintf(w, "%s:%d", line.Function.Name, line.Line)
}
fmt.Fprintf(w, ")")
}
}
// Test that profiling of division operations is okay, especially on ARM. See issue 6681.
func TestMathBigDivide(t *testing.T) {
testCPUProfile(t, nil, func(duration time.Duration) {
t := time.After(duration)
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:
}
}
})
}
// stackContainsAll matches if all functions in spec (comma-separated) appear somewhere in the stack trace.
func stackContainsAll(spec string, count uintptr, stk []*profile.Location, labels map[string][]string) bool {
for _, f := range strings.Split(spec, ",") {
if !stackContains(f, count, stk, labels) {
return false
}
}
return true
}
func TestMorestack(t *testing.T) {
matches := matchAndAvoidStacks(stackContainsAll, []string{"runtime.newstack,runtime/pprof.growstack"}, avoidFunctions())
testCPUProfile(t, matches, func(duration time.Duration) {
t := time.After(duration)
c := make(chan bool)
for {
go func() {
growstack1()
c <- true
}()
select {
case <-t:
return
case <-c:
}
}
})
}
//go:noinline
func growstack1() {
growstack(10)
}
//go:noinline
func growstack(n int) {
var buf [8 << 18]byte
use(buf)
if n > 0 {
growstack(n - 1)
}
}
//go:noinline
func use(x [8 << 18]byte) {}
func TestBlockProfile(t *testing.T) {
type TestCase struct {
name string
f func(*testing.T)
stk []string
re string
}
tests := [...]TestCase{
{
name: "chan recv",
f: blockChanRecv,
stk: []string{
"runtime.chanrecv1",
"runtime/pprof.blockChanRecv",
"runtime/pprof.TestBlockProfile",
},
re: `
[0-9]+ [0-9]+ @( 0x[[:xdigit:]]+)+
# 0x[0-9a-f]+ runtime\.chanrecv1\+0x[0-9a-f]+ .*runtime/chan.go:[0-9]+
# 0x[0-9a-f]+ runtime/pprof\.blockChanRecv\+0x[0-9a-f]+ .*runtime/pprof/pprof_test.go:[0-9]+
# 0x[0-9a-f]+ runtime/pprof\.TestBlockProfile\+0x[0-9a-f]+ .*runtime/pprof/pprof_test.go:[0-9]+
`},
{
name: "chan send",
f: blockChanSend,
stk: []string{
"runtime.chansend1",
"runtime/pprof.blockChanSend",
"runtime/pprof.TestBlockProfile",
},
re: `
[0-9]+ [0-9]+ @( 0x[[:xdigit:]]+)+
# 0x[0-9a-f]+ runtime\.chansend1\+0x[0-9a-f]+ .*runtime/chan.go:[0-9]+
# 0x[0-9a-f]+ runtime/pprof\.blockChanSend\+0x[0-9a-f]+ .*runtime/pprof/pprof_test.go:[0-9]+
# 0x[0-9a-f]+ runtime/pprof\.TestBlockProfile\+0x[0-9a-f]+ .*runtime/pprof/pprof_test.go:[0-9]+
`},
{
name: "chan close",
f: blockChanClose,
stk: []string{
"runtime.chanrecv1",
"runtime/pprof.blockChanClose",
"runtime/pprof.TestBlockProfile",
},
re: `
[0-9]+ [0-9]+ @( 0x[[:xdigit:]]+)+
# 0x[0-9a-f]+ runtime\.chanrecv1\+0x[0-9a-f]+ .*runtime/chan.go:[0-9]+
# 0x[0-9a-f]+ runtime/pprof\.blockChanClose\+0x[0-9a-f]+ .*runtime/pprof/pprof_test.go:[0-9]+
# 0x[0-9a-f]+ runtime/pprof\.TestBlockProfile\+0x[0-9a-f]+ .*runtime/pprof/pprof_test.go:[0-9]+
`},
{
name: "select recv async",
f: blockSelectRecvAsync,
stk: []string{
"runtime.selectgo",
"runtime/pprof.blockSelectRecvAsync",
"runtime/pprof.TestBlockProfile",
},
re: `
[0-9]+ [0-9]+ @( 0x[[:xdigit:]]+)+
# 0x[0-9a-f]+ runtime\.selectgo\+0x[0-9a-f]+ .*runtime/select.go:[0-9]+
# 0x[0-9a-f]+ runtime/pprof\.blockSelectRecvAsync\+0x[0-9a-f]+ .*runtime/pprof/pprof_test.go:[0-9]+
# 0x[0-9a-f]+ runtime/pprof\.TestBlockProfile\+0x[0-9a-f]+ .*runtime/pprof/pprof_test.go:[0-9]+
`},
{
name: "select send sync",
f: blockSelectSendSync,
stk: []string{
"runtime.selectgo",
"runtime/pprof.blockSelectSendSync",
"runtime/pprof.TestBlockProfile",
},
re: `
[0-9]+ [0-9]+ @( 0x[[:xdigit:]]+)+
# 0x[0-9a-f]+ runtime\.selectgo\+0x[0-9a-f]+ .*runtime/select.go:[0-9]+
# 0x[0-9a-f]+ runtime/pprof\.blockSelectSendSync\+0x[0-9a-f]+ .*runtime/pprof/pprof_test.go:[0-9]+
# 0x[0-9a-f]+ runtime/pprof\.TestBlockProfile\+0x[0-9a-f]+ .*runtime/pprof/pprof_test.go:[0-9]+
`},
{
name: "mutex",
f: blockMutex,
stk: []string{
"sync.(*Mutex).Lock",
"runtime/pprof.blockMutex",
"runtime/pprof.TestBlockProfile",
},
re: `
[0-9]+ [0-9]+ @( 0x[[:xdigit:]]+)+
# 0x[0-9a-f]+ sync\.\(\*Mutex\)\.Lock\+0x[0-9a-f]+ .*sync/mutex\.go:[0-9]+
# 0x[0-9a-f]+ runtime/pprof\.blockMutex\+0x[0-9a-f]+ .*runtime/pprof/pprof_test.go:[0-9]+
# 0x[0-9a-f]+ runtime/pprof\.TestBlockProfile\+0x[0-9a-f]+ .*runtime/pprof/pprof_test.go:[0-9]+
`},
{
name: "cond",
f: blockCond,
stk: []string{
"sync.(*Cond).Wait",
"runtime/pprof.blockCond",
"runtime/pprof.TestBlockProfile",
},
re: `
[0-9]+ [0-9]+ @( 0x[[:xdigit:]]+)+
# 0x[0-9a-f]+ sync\.\(\*Cond\)\.Wait\+0x[0-9a-f]+ .*sync/cond\.go:[0-9]+
# 0x[0-9a-f]+ runtime/pprof\.blockCond\+0x[0-9a-f]+ .*runtime/pprof/pprof_test.go:[0-9]+
# 0x[0-9a-f]+ runtime/pprof\.TestBlockProfile\+0x[0-9a-f]+ .*runtime/pprof/pprof_test.go:[0-9]+
`},
}
// Generate block profile
runtime.SetBlockProfileRate(1)
defer runtime.SetBlockProfileRate(0)
for _, test := range tests {
test.f(t)
}
t.Run("debug=1", func(t *testing.T) {
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)
}
if strings.HasSuffix(prof, "#\t0x0\n\n") {
t.Errorf("Useless 0 suffix:\n%v", prof)
}
for _, test := range tests {
if !regexp.MustCompile(strings.ReplaceAll(test.re, "\t", "\t+")).MatchString(prof) {
t.Errorf("Bad %v entry, expect:\n%v\ngot:\n%v", test.name, test.re, prof)
}
}
})
t.Run("proto", func(t *testing.T) {
// proto format
var w bytes.Buffer
Lookup("block").WriteTo(&w, 0)
p, err := profile.Parse(&w)
if err != nil {
t.Fatalf("failed to parse profile: %v", err)
}
t.Logf("parsed proto: %s", p)
if err := p.CheckValid(); err != nil {
t.Fatalf("invalid profile: %v", err)
}
stks := stacks(p)
for _, test := range tests {
if !containsStack(stks, test.stk) {
t.Errorf("No matching stack entry for %v, want %+v", test.name, test.stk)
}
}
})
}
func stacks(p *profile.Profile) (res [][]string) {
for _, s := range p.Sample {
var stk []string
for _, l := range s.Location {
for _, line := range l.Line {
stk = append(stk, line.Function.Name)
}
}
res = append(res, stk)
}
return res
}
func containsStack(got [][]string, want []string) bool {
for _, stk := range got {
if len(stk) < len(want) {
continue
}
for i, f := range want {
if f != stk[i] {
break
}
if i == len(want)-1 {
return true
}
}
}
return false
}
// awaitBlockedGoroutine spins on runtime.Gosched until a runtime stack dump
// shows a goroutine in the given state with a stack frame in
// runtime/pprof.<fName>.
func awaitBlockedGoroutine(t *testing.T, state, fName string) {
re := fmt.Sprintf(`(?m)^goroutine \d+ \[%s\]:\n(?:.+\n\t.+\n)*runtime/pprof\.%s`, regexp.QuoteMeta(state), fName)
r := regexp.MustCompile(re)
if deadline, ok := t.Deadline(); ok {
if d := time.Until(deadline); d > 1*time.Second {
timer := time.AfterFunc(d-1*time.Second, func() {
debug.SetTraceback("all")
panic(fmt.Sprintf("timed out waiting for %#q", re))
})
defer timer.Stop()
}
}
buf := make([]byte, 64<<10)
for {
runtime.Gosched()
n := runtime.Stack(buf, true)
if n == len(buf) {
// Buffer wasn't large enough for a full goroutine dump.
// Resize it and try again.
buf = make([]byte, 2*len(buf))
continue
}
if r.Match(buf[:n]) {
return
}
}
}
func blockChanRecv(t *testing.T) {
c := make(chan bool)
go func() {
awaitBlockedGoroutine(t, "chan receive", "blockChanRecv")
c <- true
}()
<-c
}
func blockChanSend(t *testing.T) {
c := make(chan bool)
go func() {
awaitBlockedGoroutine(t, "chan send", "blockChanSend")
<-c
}()
c <- true
}
func blockChanClose(t *testing.T) {
c := make(chan bool)
go func() {
awaitBlockedGoroutine(t, "chan receive", "blockChanClose")
close(c)
}()
<-c
}
func blockSelectRecvAsync(t *testing.T) {
const numTries = 3
c := make(chan bool, 1)
c2 := make(chan bool, 1)
go func() {
for i := 0; i < numTries; i++ {
awaitBlockedGoroutine(t, "select", "blockSelectRecvAsync")
c <- true
}
}()
for i := 0; i < numTries; i++ {
select {
case <-c:
case <-c2:
}
}
}
func blockSelectSendSync(t *testing.T) {
c := make(chan bool)
c2 := make(chan bool)
go func() {
awaitBlockedGoroutine(t, "select", "blockSelectSendSync")
<-c
}()
select {
case c <- true:
case c2 <- true:
}
}
func blockMutex(t *testing.T) {
var mu sync.Mutex
mu.Lock()
go func() {
awaitBlockedGoroutine(t, "semacquire", "blockMutex")
mu.Unlock()
}()
// Note: Unlock releases mu before recording the mutex event,
// so it's theoretically possible for this to proceed and
// capture the profile before the event is recorded. As long
// as this is blocked before the unlock happens, it's okay.
mu.Lock()
}
func blockCond(t *testing.T) {
var mu sync.Mutex
c := sync.NewCond(&mu)
mu.Lock()
go func() {
awaitBlockedGoroutine(t, "sync.Cond.Wait", "blockCond")
mu.Lock()
c.Signal()
mu.Unlock()
}()
c.Wait()
mu.Unlock()
}
// See http://golang.org/cl/299991.
func TestBlockProfileBias(t *testing.T) {
rate := int(1000) // arbitrary value
runtime.SetBlockProfileRate(rate)
defer runtime.SetBlockProfileRate(0)
// simulate blocking events
blockFrequentShort(rate)
blockInfrequentLong(rate)
var w bytes.Buffer
Lookup("block").WriteTo(&w, 0)
p, err := profile.Parse(&w)
if err != nil {
t.Fatalf("failed to parse profile: %v", err)
}
t.Logf("parsed proto: %s", p)
il := float64(-1) // blockInfrequentLong duration
fs := float64(-1) // blockFrequentShort duration
for _, s := range p.Sample {
for _, l := range s.Location {
for _, line := range l.Line {
if len(s.Value) < 2 {
t.Fatal("block profile has less than 2 sample types")
}
if line.Function.Name == "runtime/pprof.blockInfrequentLong" {
il = float64(s.Value[1])
} else if line.Function.Name == "runtime/pprof.blockFrequentShort" {
fs = float64(s.Value[1])
}
}
}
}
if il == -1 || fs == -1 {
t.Fatal("block profile is missing expected functions")
}
// stddev of bias from 100 runs on local machine multiplied by 10x
const threshold = 0.2
if bias := (il - fs) / il; math.Abs(bias) > threshold {
t.Fatalf("bias: abs(%f) > %f", bias, threshold)
} else {
t.Logf("bias: abs(%f) < %f", bias, threshold)
}
}
// blockFrequentShort produces 100000 block events with an average duration of
// rate / 10.
func blockFrequentShort(rate int) {
for i := 0; i < 100000; i++ {
blockevent(int64(rate/10), 1)
}
}
// blockFrequentShort produces 10000 block events with an average duration of
// rate.
func blockInfrequentLong(rate int) {
for i := 0; i < 10000; i++ {
blockevent(int64(rate), 1)
}
}
// Used by TestBlockProfileBias.
//
//go:linkname blockevent runtime.blockevent
func blockevent(cycles int64, skip int)
func TestMutexProfile(t *testing.T) {
// Generate mutex profile
old := runtime.SetMutexProfileFraction(1)
defer runtime.SetMutexProfileFraction(old)
if old != 0 {
t.Fatalf("need MutexProfileRate 0, got %d", old)
}
blockMutex(t)
t.Run("debug=1", func(t *testing.T) {
var w bytes.Buffer
Lookup("mutex").WriteTo(&w, 1)
prof := w.String()
t.Logf("received profile: %v", prof)
if !strings.HasPrefix(prof, "--- mutex:\ncycles/second=") {
t.Errorf("Bad profile header:\n%v", prof)
}
prof = strings.Trim(prof, "\n")
lines := strings.Split(prof, "\n")
if len(lines) != 6 {
t.Errorf("expected 6 lines, got %d %q\n%s", len(lines), prof, prof)
}
if len(lines) < 6 {
return
}
// checking that the line is like "35258904 1 @ 0x48288d 0x47cd28 0x458931"
r2 := `^\d+ \d+ @(?: 0x[[:xdigit:]]+)+`
//r2 := "^[0-9]+ 1 @ 0x[0-9a-f x]+$"
if ok, err := regexp.MatchString(r2, lines[3]); err != nil || !ok {
t.Errorf("%q didn't match %q", lines[3], r2)
}
r3 := "^#.*runtime/pprof.blockMutex.*$"
if ok, err := regexp.MatchString(r3, lines[5]); err != nil || !ok {
t.Errorf("%q didn't match %q", lines[5], r3)
}
t.Logf(prof)
})
t.Run("proto", func(t *testing.T) {
// proto format
var w bytes.Buffer
Lookup("mutex").WriteTo(&w, 0)
p, err := profile.Parse(&w)
if err != nil {
t.Fatalf("failed to parse profile: %v", err)
}
t.Logf("parsed proto: %s", p)
if err := p.CheckValid(); err != nil {
t.Fatalf("invalid profile: %v", err)
}
stks := stacks(p)
for _, want := range [][]string{
{"sync.(*Mutex).Unlock", "runtime/pprof.blockMutex.func1"},
} {
if !containsStack(stks, want) {
t.Errorf("No matching stack entry for %+v", want)
}
}
})
}
func func1(c chan int) { <-c }
func func2(c chan int) { <-c }
func func3(c chan int) { <-c }
func func4(c chan int) { <-c }
func TestGoroutineCounts(t *testing.T) {
// Setting GOMAXPROCS to 1 ensures we can force all goroutines to the
// desired blocking point.
defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1))
c := make(chan int)
for i := 0; i < 100; i++ {
switch {
case i%10 == 0:
go func1(c)
case i%2 == 0:
go func2(c)
default:
go func3(c)
}
// Let goroutines block on channel
for j := 0; j < 5; j++ {
runtime.Gosched()
}
}
ctx := context.Background()
// ... and again, with labels this time (just with fewer iterations to keep
// sorting deterministic).
Do(ctx, Labels("label", "value"), func(context.Context) {
for i := 0; i < 89; i++ {
switch {
case i%10 == 0:
go func1(c)
case i%2 == 0:
go func2(c)
default:
go func3(c)
}
// Let goroutines block on channel
for j := 0; j < 5; j++ {
runtime.Gosched()
}
}
})
var w bytes.Buffer
goroutineProf := Lookup("goroutine")
// Check debug profile
goroutineProf.WriteTo(&w, 1)
prof := w.String()
labels := labelMap{"label": "value"}
labelStr := "\n# labels: " + labels.String()
if !containsInOrder(prof, "\n50 @ ", "\n44 @", labelStr,
"\n40 @", "\n36 @", labelStr, "\n10 @", "\n9 @", labelStr, "\n1 @") {
t.Errorf("expected sorted goroutine counts with Labels:\n%s", prof)
}
// Check proto profile
w.Reset()
goroutineProf.WriteTo(&w, 0)
p, err := profile.Parse(&w)
if err != nil {
t.Errorf("error parsing protobuf profile: %v", err)
}
if err := p.CheckValid(); err != nil {
t.Errorf("protobuf profile is invalid: %v", err)
}
expectedLabels := map[int64]map[string]string{
50: map[string]string{},
44: map[string]string{"label": "value"},
40: map[string]string{},
36: map[string]string{"label": "value"},
10: map[string]string{},
9: map[string]string{"label": "value"},
1: map[string]string{},
}
if !containsCountsLabels(p, expectedLabels) {
t.Errorf("expected count profile to contain goroutines with counts and labels %v, got %v",
expectedLabels, p)
}
close(c)
time.Sleep(10 * time.Millisecond) // let goroutines exit
}
func containsInOrder(s string, all ...string) bool {
for _, t := range all {
var ok bool
if _, s, ok = strings.Cut(s, t); !ok {
return false
}
}
return true
}
func containsCountsLabels(prof *profile.Profile, countLabels map[int64]map[string]string) bool {
m := make(map[int64]int)
type nkey struct {
count int64
key, val string
}
n := make(map[nkey]int)
for c, kv := range countLabels {
m[c]++
for k, v := range kv {
n[nkey{
count: c,
key: k,
val: v,
}]++
}
}
for _, s := range prof.Sample {
// The count is the single value in the sample
if len(s.Value) != 1 {
return false
}
m[s.Value[0]]--
for k, vs := range s.Label {
for _, v := range vs {
n[nkey{
count: s.Value[0],
key: k,
val: v,
}]--
}
}
}
for _, n := range m {
if n > 0 {
return false
}
}
for _, ncnt := range n {
if ncnt != 0 {
return false
}
}
return true
}
func TestGoroutineProfileConcurrency(t *testing.T) {
goroutineProf := Lookup("goroutine")
profilerCalls := func(s string) int {
return strings.Count(s, "\truntime/pprof.runtime_goroutineProfileWithLabels+")
}
includesFinalizer := func(s string) bool {
return strings.Contains(s, "runtime.runfinq")
}
// Concurrent calls to the goroutine profiler should not trigger data races
// or corruption.
t.Run("overlapping profile requests", func(t *testing.T) {
ctx := context.Background()
ctx, cancel := context.WithTimeout(ctx, 10*time.Second)
defer cancel()
var wg sync.WaitGroup
for i := 0; i < 2; i++ {
wg.Add(1)
Do(ctx, Labels("i", fmt.Sprint(i)), func(context.Context) {
go func() {
defer wg.Done()
for ctx.Err() == nil {
var w bytes.Buffer
goroutineProf.WriteTo(&w, 1)
prof := w.String()
count := profilerCalls(prof)
if count >= 2 {
t.Logf("prof %d\n%s", count, prof)
cancel()
}
}
}()
})
}
wg.Wait()
})
// The finalizer goroutine should not show up in most profiles, since it's
// marked as a system goroutine when idle.
t.Run("finalizer not present", func(t *testing.T) {
var w bytes.Buffer
goroutineProf.WriteTo(&w, 1)
prof := w.String()
if includesFinalizer(prof) {
t.Errorf("profile includes finalizer (but finalizer should be marked as system):\n%s", prof)
}
})
// The finalizer goroutine should show up when it's running user code.
t.Run("finalizer present", func(t *testing.T) {
obj := new(byte)
ch1, ch2 := make(chan int), make(chan int)
defer close(ch2)
runtime.SetFinalizer(obj, func(_ interface{}) {
close(ch1)
<-ch2
})
obj = nil
for i := 10; i >= 0; i-- {
select {
case <-ch1:
default:
if i == 0 {
t.Fatalf("finalizer did not run")
}
runtime.GC()
}
}
var w bytes.Buffer
goroutineProf.WriteTo(&w, 1)
prof := w.String()
if !includesFinalizer(prof) {
t.Errorf("profile does not include finalizer (and it should be marked as user):\n%s", prof)
}
})
// Check that new goroutines only show up in order.
testLaunches := func(t *testing.T) {
var done sync.WaitGroup
defer done.Wait()
ctx := context.Background()
ctx, cancel := context.WithCancel(ctx)
defer cancel()
ch := make(chan int)
defer close(ch)
var ready sync.WaitGroup
// These goroutines all survive until the end of the subtest, so we can
// check that a (numbered) goroutine appearing in the profile implies
// that all older goroutines also appear in the profile.
ready.Add(1)
done.Add(1)
go func() {
defer done.Done()
for i := 0; ctx.Err() == nil; i++ {
// Use SetGoroutineLabels rather than Do we can always expect an
// extra goroutine (this one) with most recent label.
SetGoroutineLabels(WithLabels(ctx, Labels(t.Name()+"-loop-i", fmt.Sprint(i))))
done.Add(1)
go func() {
<-ch
done.Done()
}()
for j := 0; j < i; j++ {
// Spin for longer and longer as the test goes on. This
// goroutine will do O(N^2) work with the number of
// goroutines it launches. This should be slow relative to
// the work involved in collecting a goroutine profile,
// which is O(N) with the high-water mark of the number of
// goroutines in this process (in the allgs slice).
runtime.Gosched()
}
if i == 0 {
ready.Done()
}
}
}()
// Short-lived goroutines exercise different code paths (goroutines with
// status _Gdead, for instance). This churn doesn't have behavior that
// we can test directly, but does help to shake out data races.
ready.Add(1)
var churn func(i int)
churn = func(i int) {
SetGoroutineLabels(WithLabels(ctx, Labels(t.Name()+"-churn-i", fmt.Sprint(i))))
if i == 0 {
ready.Done()
} else if i%16 == 0 {
// Yield on occasion so this sequence of goroutine launches
// doesn't monopolize a P. See issue #52934.
runtime.Gosched()
}
if ctx.Err() == nil {
go churn(i + 1)
}
}
go func() {
churn(0)
}()
ready.Wait()
var w [3]bytes.Buffer
for i := range w {
goroutineProf.WriteTo(&w[i], 0)
}
for i := range w {
p, err := profile.Parse(bytes.NewReader(w[i].Bytes()))
if err != nil {
t.Errorf("error parsing protobuf profile: %v", err)
}
// High-numbered loop-i goroutines imply that every lower-numbered
// loop-i goroutine should be present in the profile too.
counts := make(map[string]int)
for _, s := range p.Sample {
label := s.Label[t.Name()+"-loop-i"]
if len(label) > 0 {
counts[label[0]]++
}
}
for j, max := 0, len(counts)-1; j <= max; j++ {
n := counts[fmt.Sprint(j)]
if n == 1 || (n == 2 && j == max) {
continue
}
t.Errorf("profile #%d's goroutines with label loop-i:%d; %d != 1 (or 2 for the last entry, %d)",
i+1, j, n, max)
t.Logf("counts %v", counts)
break
}
}
}
runs := 100
if testing.Short() {
runs = 5
}
for i := 0; i < runs; i++ {
// Run multiple times to shake out data races
t.Run("goroutine launches", testLaunches)
}
}
func BenchmarkGoroutine(b *testing.B) {
withIdle := func(n int, fn func(b *testing.B)) func(b *testing.B) {
return func(b *testing.B) {
c := make(chan int)
var ready, done sync.WaitGroup
defer func() {
close(c)
done.Wait()
}()
for i := 0; i < n; i++ {
ready.Add(1)
done.Add(1)
go func() {
ready.Done()
<-c
done.Done()
}()
}
// Let goroutines block on channel
ready.Wait()
for i := 0; i < 5; i++ {
runtime.Gosched()
}
fn(b)
}
}
withChurn := func(fn func(b *testing.B)) func(b *testing.B) {
return func(b *testing.B) {
ctx := context.Background()
ctx, cancel := context.WithCancel(ctx)
defer cancel()
var ready sync.WaitGroup
ready.Add(1)
var count int64
var churn func(i int)
churn = func(i int) {
SetGoroutineLabels(WithLabels(ctx, Labels("churn-i", fmt.Sprint(i))))
atomic.AddInt64(&count, 1)
if i == 0 {
ready.Done()
}
if ctx.Err() == nil {
go churn(i + 1)
}
}
go func() {
churn(0)
}()
ready.Wait()
fn(b)
b.ReportMetric(float64(atomic.LoadInt64(&count))/float64(b.N), "concurrent_launches/op")
}
}
benchWriteTo := func(b *testing.B) {
goroutineProf := Lookup("goroutine")
b.ResetTimer()
for i := 0; i < b.N; i++ {
goroutineProf.WriteTo(io.Discard, 0)
}
b.StopTimer()
}
benchGoroutineProfile := func(b *testing.B) {
p := make([]runtime.StackRecord, 10000)
b.ResetTimer()
for i := 0; i < b.N; i++ {
runtime.GoroutineProfile(p)
}
b.StopTimer()
}
// Note that some costs of collecting a goroutine profile depend on the
// length of the runtime.allgs slice, which never shrinks. Stay within race
// detector's 8k-goroutine limit
for _, n := range []int{50, 500, 5000} {
b.Run(fmt.Sprintf("Profile.WriteTo idle %d", n), withIdle(n, benchWriteTo))
b.Run(fmt.Sprintf("Profile.WriteTo churn %d", n), withIdle(n, withChurn(benchWriteTo)))
b.Run(fmt.Sprintf("runtime.GoroutineProfile churn %d", n), withIdle(n, withChurn(benchGoroutineProfile)))
}
}
var emptyCallStackTestRun int64
// Issue 18836.
func TestEmptyCallStack(t *testing.T) {
name := fmt.Sprintf("test18836_%d", emptyCallStackTestRun)
emptyCallStackTestRun++
t.Parallel()
var buf bytes.Buffer
p := NewProfile(name)
p.Add("foo", 47674)
p.WriteTo(&buf, 1)
p.Remove("foo")
got := buf.String()
prefix := name + " profile: total 1\n"
if !strings.HasPrefix(got, prefix) {
t.Fatalf("got:\n\t%q\nwant prefix:\n\t%q\n", got, prefix)
}
lostevent := "lostProfileEvent"
if !strings.Contains(got, lostevent) {
t.Fatalf("got:\n\t%q\ndoes not contain:\n\t%q\n", got, lostevent)
}
}
// stackContainsLabeled takes a spec like funcname;key=value and matches if the stack has that key
// and value and has funcname somewhere in the stack.
func stackContainsLabeled(spec string, count uintptr, stk []*profile.Location, labels map[string][]string) bool {
base, kv, ok := strings.Cut(spec, ";")
if !ok {
panic("no semicolon in key/value spec")
}
k, v, ok := strings.Cut(kv, "=")
if !ok {
panic("missing = in key/value spec")
}
if !contains(labels[k], v) {
return false
}
return stackContains(base, count, stk, labels)
}
func TestCPUProfileLabel(t *testing.T) {
matches := matchAndAvoidStacks(stackContainsLabeled, []string{"runtime/pprof.cpuHogger;key=value"}, avoidFunctions())
testCPUProfile(t, matches, func(dur time.Duration) {
Do(context.Background(), Labels("key", "value"), func(context.Context) {
cpuHogger(cpuHog1, &salt1, dur)
})
})
}
func TestLabelRace(t *testing.T) {
// Test the race detector annotations for synchronization
// between setting labels and consuming them from the
// profile.
matches := matchAndAvoidStacks(stackContainsLabeled, []string{"runtime/pprof.cpuHogger;key=value"}, nil)
testCPUProfile(t, matches, func(dur time.Duration) {
start := time.Now()
var wg sync.WaitGroup
for time.Since(start) < dur {
var salts [10]int
for i := 0; i < 10; i++ {
wg.Add(1)
go func(j int) {
Do(context.Background(), Labels("key", "value"), func(context.Context) {
cpuHogger(cpuHog1, &salts[j], time.Millisecond)
})
wg.Done()
}(i)
}
wg.Wait()
}
})
}
func TestGoroutineProfileLabelRace(t *testing.T) {
// Test the race detector annotations for synchronization
// between setting labels and consuming them from the
// goroutine profile. See issue #50292.
t.Run("reset", func(t *testing.T) {
ctx := context.Background()
ctx, cancel := context.WithCancel(ctx)
defer cancel()
go func() {
goroutineProf := Lookup("goroutine")
for ctx.Err() == nil {
var w bytes.Buffer
goroutineProf.WriteTo(&w, 1)
prof := w.String()
if strings.Contains(prof, "loop-i") {
cancel()
}
}
}()
for i := 0; ctx.Err() == nil; i++ {
Do(ctx, Labels("loop-i", fmt.Sprint(i)), func(ctx context.Context) {
})
}
})
t.Run("churn", func(t *testing.T) {
ctx := context.Background()
ctx, cancel := context.WithCancel(ctx)
defer cancel()
var ready sync.WaitGroup
ready.Add(1)
var churn func(i int)
churn = func(i int) {
SetGoroutineLabels(WithLabels(ctx, Labels("churn-i", fmt.Sprint(i))))
if i == 0 {
ready.Done()
}
if ctx.Err() == nil {
go churn(i + 1)
}
}
go func() {
churn(0)
}()
ready.Wait()
goroutineProf := Lookup("goroutine")
for i := 0; i < 10; i++ {
goroutineProf.WriteTo(io.Discard, 1)
}
})
}
// TestLabelSystemstack makes sure CPU profiler samples of goroutines running
// on systemstack include the correct pprof labels. See issue #48577
func TestLabelSystemstack(t *testing.T) {
// Grab and re-set the initial value before continuing to ensure
// GOGC doesn't actually change following the test.
gogc := debug.SetGCPercent(100)
debug.SetGCPercent(gogc)
matches := matchAndAvoidStacks(stackContainsLabeled, []string{"runtime.systemstack;key=value"}, avoidFunctions())
p := testCPUProfile(t, matches, func(dur time.Duration) {
Do(context.Background(), Labels("key", "value"), func(ctx context.Context) {
parallelLabelHog(ctx, dur, gogc)
})
})
// Two conditions to check:
// * labelHog should always be labeled.
// * The label should _only_ appear on labelHog and the Do call above.
for _, s := range p.Sample {
isLabeled := s.Label != nil && contains(s.Label["key"], "value")
var (
mayBeLabeled bool
mustBeLabeled bool
mustNotBeLabeled bool
)
for _, loc := range s.Location {
for _, l := range loc.Line {
switch l.Function.Name {
case "runtime/pprof.labelHog", "runtime/pprof.parallelLabelHog", "runtime/pprof.parallelLabelHog.func1":
mustBeLabeled = true
case "runtime/pprof.Do":
// Do sets the labels, so samples may
// or may not be labeled depending on
// which part of the function they are
// at.
mayBeLabeled = true
case "runtime.bgsweep", "runtime.bgscavenge", "runtime.forcegchelper", "runtime.gcBgMarkWorker", "runtime.runfinq", "runtime.sysmon":
// Runtime system goroutines or threads
// (such as those identified by
// runtime.isSystemGoroutine). These
// should never be labeled.
mustNotBeLabeled = true
case "gogo", "gosave_systemstack_switch", "racecall":
// These are context switch/race
// critical that we can't do a full
// traceback from. Typically this would
// be covered by the runtime check
// below, but these symbols don't have
// the package name.
mayBeLabeled = true
}
if strings.HasPrefix(l.Function.Name, "runtime.") {
// There are many places in the runtime
// where we can't do a full traceback.
// Ideally we'd list them all, but
// barring that allow anything in the
// runtime, unless explicitly excluded
// above.
mayBeLabeled = true
}
}
}
if mustNotBeLabeled {
// If this must not be labeled, then mayBeLabeled hints
// are not relevant.
mayBeLabeled = false
}
if mustBeLabeled && !isLabeled {
var buf bytes.Buffer
fprintStack(&buf, s.Location)
t.Errorf("Sample labeled got false want true: %s", buf.String())
}
if mustNotBeLabeled && isLabeled {
var buf bytes.Buffer
fprintStack(&buf, s.Location)
t.Errorf("Sample labeled got true want false: %s", buf.String())
}
if isLabeled && !(mayBeLabeled || mustBeLabeled) {
var buf bytes.Buffer
fprintStack(&buf, s.Location)
t.Errorf("Sample labeled got true want false: %s", buf.String())
}
}
}
// labelHog is designed to burn CPU time in a way that a high number of CPU
// samples end up running on systemstack.
func labelHog(stop chan struct{}, gogc int) {
// Regression test for issue 50032. We must give GC an opportunity to
// be initially triggered by a labelled goroutine.
runtime.GC()
for i := 0; ; i++ {
select {
case <-stop:
return
default:
debug.SetGCPercent(gogc)
}
}
}
// parallelLabelHog runs GOMAXPROCS goroutines running labelHog.
func parallelLabelHog(ctx context.Context, dur time.Duration, gogc int) {
var wg sync.WaitGroup
stop := make(chan struct{})
for i := 0; i < runtime.GOMAXPROCS(0); i++ {
wg.Add(1)
go func() {
defer wg.Done()
labelHog(stop, gogc)
}()
}
time.Sleep(dur)
close(stop)
wg.Wait()
}
// Check that there is no deadlock when the program receives SIGPROF while in
// 64bit atomics' critical section. Used to happen on mips{,le}. See #20146.
func TestAtomicLoadStore64(t *testing.T) {
f, err := os.CreateTemp("", "profatomic")
if err != nil {
t.Fatalf("TempFile: %v", err)
}
defer os.Remove(f.Name())
defer f.Close()
if err := StartCPUProfile(f); err != nil {
t.Fatal(err)
}
defer StopCPUProfile()
var flag uint64
done := make(chan bool, 1)
go func() {
for atomic.LoadUint64(&flag) == 0 {
runtime.Gosched()
}
done <- true
}()
time.Sleep(50 * time.Millisecond)
atomic.StoreUint64(&flag, 1)
<-done
}
func TestTracebackAll(t *testing.T) {
// With gccgo, if a profiling signal arrives at the wrong time
// during traceback, it may crash or hang. See issue #29448.
f, err := os.CreateTemp("", "proftraceback")
if err != nil {
t.Fatalf("TempFile: %v", err)
}
defer os.Remove(f.Name())
defer f.Close()
if err := StartCPUProfile(f); err != nil {
t.Fatal(err)
}
defer StopCPUProfile()
ch := make(chan int)
defer close(ch)
count := 10
for i := 0; i < count; i++ {
go func() {
<-ch // block
}()
}
N := 10000
if testing.Short() {
N = 500
}
buf := make([]byte, 10*1024)
for i := 0; i < N; i++ {
runtime.Stack(buf, true)
}
}
// TestTryAdd tests the cases that are hard to test with real program execution.
//
// For example, the current go compilers may not always inline functions
// involved in recursion but that may not be true in the future compilers. This
// tests such cases by using fake call sequences and forcing the profile build
// utilizing translateCPUProfile defined in proto_test.go
func TestTryAdd(t *testing.T) {
if _, found := findInlinedCall(inlinedCallerDump, 4<<10); !found {
t.Skip("Can't determine whether anything was inlined into inlinedCallerDump.")
}
// inlinedCallerDump
// inlinedCalleeDump
pcs := make([]uintptr, 2)
inlinedCallerDump(pcs)
inlinedCallerStack := make([]uint64, 2)
for i := range pcs {
inlinedCallerStack[i] = uint64(pcs[i])
}
if _, found := findInlinedCall(recursionChainBottom, 4<<10); !found {
t.Skip("Can't determine whether anything was inlined into recursionChainBottom.")
}
// recursionChainTop
// recursionChainMiddle
// recursionChainBottom
// recursionChainTop
// recursionChainMiddle
// recursionChainBottom
pcs = make([]uintptr, 6)
recursionChainTop(1, pcs)
recursionStack := make([]uint64, len(pcs))
for i := range pcs {
recursionStack[i] = uint64(pcs[i])
}
period := int64(2000 * 1000) // 1/500*1e9 nanosec.
testCases := []struct {
name string
input []uint64 // following the input format assumed by profileBuilder.addCPUData.
count int // number of records in input.
wantLocs [][]string // ordered location entries with function names.
wantSamples []*profile.Sample // ordered samples, we care only about Value and the profile location IDs.
}{{
// Sanity test for a normal, complete stack trace.
name: "full_stack_trace",
input: []uint64{
3, 0, 500, // hz = 500. Must match the period.
5, 0, 50, inlinedCallerStack[0], inlinedCallerStack[1],
},
count: 2,
wantLocs: [][]string{
{"runtime/pprof.inlinedCalleeDump", "runtime/pprof.inlinedCallerDump"},
},
wantSamples: []*profile.Sample{
{Value: []int64{50, 50 * period}, Location: []*profile.Location{{ID: 1}}},
},
}, {
name: "bug35538",
input: []uint64{
3, 0, 500, // hz = 500. Must match the period.
// Fake frame: tryAdd will have inlinedCallerDump
// (stack[1]) on the deck when it encounters the next
// inline function. It should accept this.
7, 0, 10, inlinedCallerStack[0], inlinedCallerStack[1], inlinedCallerStack[0], inlinedCallerStack[1],
5, 0, 20, inlinedCallerStack[0], inlinedCallerStack[1],
},
count: 3,
wantLocs: [][]string{{"runtime/pprof.inlinedCalleeDump", "runtime/pprof.inlinedCallerDump"}},
wantSamples: []*profile.Sample{
{Value: []int64{10, 10 * period}, Location: []*profile.Location{{ID: 1}, {ID: 1}}},
{Value: []int64{20, 20 * period}, Location: []*profile.Location{{ID: 1}}},
},
}, {
name: "bug38096",
input: []uint64{
3, 0, 500, // hz = 500. Must match the period.
// count (data[2]) == 0 && len(stk) == 1 is an overflow
// entry. The "stk" entry is actually the count.
4, 0, 0, 4242,
},
count: 2,
wantLocs: [][]string{{"runtime/pprof.lostProfileEvent"}},
wantSamples: []*profile.Sample{
{Value: []int64{4242, 4242 * period}, Location: []*profile.Location{{ID: 1}}},
},
}, {
// If a function is directly called recursively then it must
// not be inlined in the caller.
//
// N.B. We're generating an impossible profile here, with a
// recursive inlineCalleeDump call. This is simulating a non-Go
// function that looks like an inlined Go function other than
// its recursive property. See pcDeck.tryAdd.
name: "directly_recursive_func_is_not_inlined",
input: []uint64{
3, 0, 500, // hz = 500. Must match the period.
5, 0, 30, inlinedCallerStack[0], inlinedCallerStack[0],
4, 0, 40, inlinedCallerStack[0],
},
count: 3,
// inlinedCallerDump shows up here because
// runtime_expandFinalInlineFrame adds it to the stack frame.
wantLocs: [][]string{{"runtime/pprof.inlinedCalleeDump"}, {"runtime/pprof.inlinedCallerDump"}},
wantSamples: []*profile.Sample{
{Value: []int64{30, 30 * period}, Location: []*profile.Location{{ID: 1}, {ID: 1}, {ID: 2}}},
{Value: []int64{40, 40 * period}, Location: []*profile.Location{{ID: 1}, {ID: 2}}},
},
}, {
name: "recursion_chain_inline",
input: []uint64{
3, 0, 500, // hz = 500. Must match the period.
9, 0, 10, recursionStack[0], recursionStack[1], recursionStack[2], recursionStack[3], recursionStack[4], recursionStack[5],
},
count: 2,
wantLocs: [][]string{
{"runtime/pprof.recursionChainBottom"},
{
"runtime/pprof.recursionChainMiddle",
"runtime/pprof.recursionChainTop",
"runtime/pprof.recursionChainBottom",
},
{
"runtime/pprof.recursionChainMiddle",
"runtime/pprof.recursionChainTop",
"runtime/pprof.TestTryAdd", // inlined into the test.
},
},
wantSamples: []*profile.Sample{
{Value: []int64{10, 10 * period}, Location: []*profile.Location{{ID: 1}, {ID: 2}, {ID: 3}}},
},
}, {
name: "truncated_stack_trace_later",
input: []uint64{
3, 0, 500, // hz = 500. Must match the period.
5, 0, 50, inlinedCallerStack[0], inlinedCallerStack[1],
4, 0, 60, inlinedCallerStack[0],
},
count: 3,
wantLocs: [][]string{{"runtime/pprof.inlinedCalleeDump", "runtime/pprof.inlinedCallerDump"}},
wantSamples: []*profile.Sample{
{Value: []int64{50, 50 * period}, Location: []*profile.Location{{ID: 1}}},
{Value: []int64{60, 60 * period}, Location: []*profile.Location{{ID: 1}}},
},
}, {
name: "truncated_stack_trace_first",
input: []uint64{
3, 0, 500, // hz = 500. Must match the period.
4, 0, 70, inlinedCallerStack[0],
5, 0, 80, inlinedCallerStack[0], inlinedCallerStack[1],
},
count: 3,
wantLocs: [][]string{{"runtime/pprof.inlinedCalleeDump", "runtime/pprof.inlinedCallerDump"}},
wantSamples: []*profile.Sample{
{Value: []int64{70, 70 * period}, Location: []*profile.Location{{ID: 1}}},
{Value: []int64{80, 80 * period}, Location: []*profile.Location{{ID: 1}}},
},
}, {
// We can recover the inlined caller from a truncated stack.
name: "truncated_stack_trace_only",
input: []uint64{
3, 0, 500, // hz = 500. Must match the period.
4, 0, 70, inlinedCallerStack[0],
},
count: 2,
wantLocs: [][]string{{"runtime/pprof.inlinedCalleeDump", "runtime/pprof.inlinedCallerDump"}},
wantSamples: []*profile.Sample{
{Value: []int64{70, 70 * period}, Location: []*profile.Location{{ID: 1}}},
},
}, {
// The same location is used for duplicated stacks.
name: "truncated_stack_trace_twice",
input: []uint64{
3, 0, 500, // hz = 500. Must match the period.
4, 0, 70, inlinedCallerStack[0],
// Fake frame: add a fake call to
// inlinedCallerDump to prevent this sample
// from getting merged into above.
5, 0, 80, inlinedCallerStack[1], inlinedCallerStack[0],
},
count: 3,
wantLocs: [][]string{
{"runtime/pprof.inlinedCalleeDump", "runtime/pprof.inlinedCallerDump"},
{"runtime/pprof.inlinedCallerDump"},
},
wantSamples: []*profile.Sample{
{Value: []int64{70, 70 * period}, Location: []*profile.Location{{ID: 1}}},
{Value: []int64{80, 80 * period}, Location: []*profile.Location{{ID: 2}, {ID: 1}}},
},
}}
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
p, err := translateCPUProfile(tc.input, tc.count)
if err != nil {
t.Fatalf("translating profile: %v", err)
}
t.Logf("Profile: %v\n", p)
// One location entry with all inlined functions.
var gotLoc [][]string
for _, loc := range p.Location {
var names []string
for _, line := range loc.Line {
names = append(names, line.Function.Name)
}
gotLoc = append(gotLoc, names)
}
if got, want := fmtJSON(gotLoc), fmtJSON(tc.wantLocs); got != want {
t.Errorf("Got Location = %+v\n\twant %+v", got, want)
}
// All samples should point to one location.
var gotSamples []*profile.Sample
for _, sample := range p.Sample {
var locs []*profile.Location
for _, loc := range sample.Location {
locs = append(locs, &profile.Location{ID: loc.ID})
}
gotSamples = append(gotSamples, &profile.Sample{Value: sample.Value, Location: locs})
}
if got, want := fmtJSON(gotSamples), fmtJSON(tc.wantSamples); got != want {
t.Errorf("Got Samples = %+v\n\twant %+v", got, want)
}
})
}
}
func TestTimeVDSO(t *testing.T) {
// Test that time functions have the right stack trace. In particular,
// it shouldn't be recursive.
if runtime.GOOS == "android" {
// Flaky on Android, issue 48655. VDSO may not be enabled.
testenv.SkipFlaky(t, 48655)
}
matches := matchAndAvoidStacks(stackContains, []string{"time.now"}, avoidFunctions())
p := testCPUProfile(t, matches, func(dur time.Duration) {
t0 := time.Now()
for {
t := time.Now()
if t.Sub(t0) >= dur {
return
}
}
})
// Check for recursive time.now sample.
for _, sample := range p.Sample {
var seenNow bool
for _, loc := range sample.Location {
for _, line := range loc.Line {
if line.Function.Name == "time.now" {
if seenNow {
t.Fatalf("unexpected recursive time.now")
}
seenNow = true
}
}
}
}
}
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