Reverting merge from trunk

[official-gcc.git] / libgo / go / 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.

package pprof_test

import (
        "bytes"
        "fmt"
        "hash/crc32"
        "os/exec"
        "regexp"
        "runtime"
        . "runtime/pprof"
        "strings"
        "sync"
        "testing"
        "time"
        "unsafe"
)

func TestCPUProfile(t *testing.T) {
        buf := make([]byte, 100000)
        testCPUProfile(t, []string{"crc32.update"}, func() {
                // This loop takes about a quarter second on a 2 GHz laptop.
                // We only need to get one 100 Hz clock tick, so we've got
                // a 25x safety buffer.
                for i := 0; i < 1000; i++ {
                        crc32.ChecksumIEEE(buf)
                }
        })
}

func TestCPUProfileMultithreaded(t *testing.T) {
        buf := make([]byte, 100000)
        defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(2))
        testCPUProfile(t, []string{"crc32.update"}, func() {
                c := make(chan int)
                go func() {
                        for i := 0; i < 2000; i++ {
                                crc32.Update(0, crc32.IEEETable, buf)
                        }
                        c <- 1
                }()
                // This loop takes about a quarter second on a 2 GHz laptop.
                // We only need to get one 100 Hz clock tick, so we've got
                // a 25x safety buffer.
                for i := 0; i < 2000; i++ {
                        crc32.ChecksumIEEE(buf)
                }
                <-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 ChecksumIEEE.
        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
                                }
                        }
                }
        })

        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
        }
        min := total / uintptr(len(have)) / 3
        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) {
        if runtime.GOOS == "windows" {
                t.Skip("flaky test; see http://golang.org/issue/6417")
        }
        // 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" {
                                        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())
                        }
                })
        }
}

// Operating systems that are expected to fail the tests. See issue 6047.
var badOS = map[string]bool{
        "darwin":  true,
        "netbsd":  true,
        "openbsd": true,
}

func TestBlockProfile(t *testing.T) {
        t.Skip("lots of details are different for gccgo; FIXME")
        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/pkg/runtime/chan.c:[0-9]+
#       0x[0-9,a-f]+    runtime/pprof_test\.blockChanRecv\+0x[0-9,a-f]+ .*/src/pkg/runtime/pprof/pprof_test.go:[0-9]+
#       0x[0-9,a-f]+    runtime/pprof_test\.TestBlockProfile\+0x[0-9,a-f]+      .*/src/pkg/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/pkg/runtime/chan.c:[0-9]+
#       0x[0-9,a-f]+    runtime/pprof_test\.blockChanSend\+0x[0-9,a-f]+ .*/src/pkg/runtime/pprof/pprof_test.go:[0-9]+
#       0x[0-9,a-f]+    runtime/pprof_test\.TestBlockProfile\+0x[0-9,a-f]+      .*/src/pkg/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/pkg/runtime/chan.c:[0-9]+
#       0x[0-9,a-f]+    runtime/pprof_test\.blockChanClose\+0x[0-9,a-f]+        .*/src/pkg/runtime/pprof/pprof_test.go:[0-9]+
#       0x[0-9,a-f]+    runtime/pprof_test\.TestBlockProfile\+0x[0-9,a-f]+      .*/src/pkg/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/pkg/runtime/chan.c:[0-9]+
#       0x[0-9,a-f]+    runtime/pprof_test\.blockSelectRecvAsync\+0x[0-9,a-f]+  .*/src/pkg/runtime/pprof/pprof_test.go:[0-9]+
#       0x[0-9,a-f]+    runtime/pprof_test\.TestBlockProfile\+0x[0-9,a-f]+      .*/src/pkg/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/pkg/runtime/chan.c:[0-9]+
#       0x[0-9,a-f]+    runtime/pprof_test\.blockSelectSendSync\+0x[0-9,a-f]+   .*/src/pkg/runtime/pprof/pprof_test.go:[0-9]+
#       0x[0-9,a-f]+    runtime/pprof_test\.TestBlockProfile\+0x[0-9,a-f]+      .*/src/pkg/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/pkg/sync/mutex\.go:[0-9]+
#       0x[0-9,a-f]+    runtime/pprof_test\.blockMutex\+0x[0-9,a-f]+    .*/src/pkg/runtime/pprof/pprof_test.go:[0-9]+
#       0x[0-9,a-f]+    runtime/pprof_test\.TestBlockProfile\+0x[0-9,a-f]+      .*/src/pkg/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()
}