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Commit ebae73bb authored by Russ Cox's avatar Russ Cox
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pprof: add Profile type 

Makes it possible for client code to maintain its own profiles,
and also reduces the API surface by giving us a type that
models built-in profiles.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5684056
parent e4b02bfd
Hide whitespace changes
Inline Side-by-side
Showing with 508 additions and 80 deletions
src/pkg/net/http/pprof/pprof.go
View file @ ebae73bb
......@@ -22,9 +22,9 @@
//
// go tool pprof http://localhost:6060/debug/pprof/profile
//
// Or to look at the thread creation profile:
// Or to view all available profiles:
//
// go tool pprof http://localhost:6060/debug/pprof/thread
// go tool pprof http://localhost:6060/debug/pprof/
//
// For a study of the facility in action, visit
//
......@@ -36,7 +36,9 @@ import (
"bufio"
"bytes"
"fmt"
"html/template"
"io"
"log"
"net/http"
"os"
"runtime"
......@@ -47,11 +49,10 @@ import (
)
func init() {
http.Handle("/debug/pprof/", http.HandlerFunc(Index))
http.Handle("/debug/pprof/cmdline", http.HandlerFunc(Cmdline))
http.Handle("/debug/pprof/profile", http.HandlerFunc(Profile))
http.Handle("/debug/pprof/heap", http.HandlerFunc(Heap))
http.Handle("/debug/pprof/symbol", http.HandlerFunc(Symbol))
http.Handle("/debug/pprof/thread", http.HandlerFunc(Thread))
}
// Cmdline responds with the running program's
......@@ -62,20 +63,6 @@ func Cmdline(w http.ResponseWriter, r *http.Request) {
fmt.Fprintf(w, strings.Join(os.Args, "\x00"))
}
// Heap responds with the pprof-formatted heap profile.
// The package initialization registers it as /debug/pprof/heap.
func Heap(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "text/plain; charset=utf-8")
pprof.WriteHeapProfile(w)
}
// Thread responds with the pprof-formatted thread creation profile.
// The package initialization registers it as /debug/pprof/thread.
func Thread(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "text/plain; charset=utf-8")
pprof.WriteThreadProfile(w)
}
// Profile responds with the pprof-formatted cpu profile.
// The package initialization registers it as /debug/pprof/profile.
func Profile(w http.ResponseWriter, r *http.Request) {
......@@ -147,3 +134,61 @@ func Symbol(w http.ResponseWriter, r *http.Request) {
w.Write(buf.Bytes())
}
// Handler returns an HTTP handler that serves the named profile.
func Handler(name string) http.Handler {
return handler(name)
}
type handler string
func (name handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "text/plain; charset=utf-8")
debug, _ := strconv.Atoi(r.FormValue("debug"))
p := pprof.Lookup(string(name))
if p == nil {
w.WriteHeader(404)
fmt.Fprintf(w, "Unknown profile: %s\n", name)
return
}
p.WriteTo(w, debug)
return
}
// Index responds with the pprof-formatted profile named by the request.
// For example, "/debug/pprof/heap" serves the "heap" profile.
// Index responds to a request for "/debug/pprof/" with an HTML page
// listing the available profiles.
func Index(w http.ResponseWriter, r *http.Request) {
if strings.HasPrefix(r.URL.Path, "/debug/pprof/") {
name := r.URL.Path[len("/debug/pprof/"):]
if name != "" {
handler(name).ServeHTTP(w, r)
return
}
}
profiles := pprof.Profiles()
if err := indexTmpl.Execute(w, profiles); err != nil {
log.Print(err)
}
}
var indexTmpl = template.Must(template.New("index").Parse(`<html>
<head>
<title>/debug/pprof/</title>
</head>
/debug/pprof/<br>
<br>
<body>
profiles:<br>
<table>
{{range .}}
<tr><td align=right>{{.Count}}<td><a href="/debug/pprof/{{.Name}}?debug=1">{{.Name}}</a>
{{end}}
</table>
<br>
<a href="/debug/pprof/goroutine?debug=2">full goroutine stack dump</a><br>
</body>
</html>
`))
src/pkg/runtime/pprof/pprof.go
View file @ ebae73bb
......@@ -10,19 +10,354 @@ package pprof
import (
"bufio"
"bytes"
"fmt"
"io"
"runtime"
"sort"
"strings"
"sync"
"text/tabwriter"
)
// BUG(rsc): CPU profiling is broken on OS X, due to an Apple kernel bug.
// For details, see http://code.google.com/p/go/source/detail?r=35b716c94225.
// WriteHeapProfile writes a pprof-formatted heap profile to w.
// If a write to w returns an error, WriteHeapProfile returns that error.
// Otherwise, WriteHeapProfile returns nil.
// A Profile is a collection of stack traces showing the call sequences
// that led to instances of a particular event, such as allocation.
// Packages can create and maintain their own profiles; the most common
// use is for tracking resources that must be explicitly closed, such as files
// or network connections.
//
// A Profile's methods can be called from multiple goroutines simultaneously.
//
// Each Profile has a unique name. A few profiles are predefined:
//
// goroutine - stack traces of all current goroutines
// heap - a sampling of all heap allocations
// threadcreate - stack traces that led to the creation of new OS threads
//
// These predefine profiles maintain themselves and panic on an explicit
// Add or Remove method call.
//
// The CPU profile is not available as a Profile. It has a special API,
// the StartCPUProfile and StopCPUProfile functions, because it streams
// output to a writer during profiling.
//
type Profile struct {
name string
mu sync.Mutex
m map[interface{}][]uintptr
count func() int
write func(io.Writer, int) error
}
// profiles records all registered profiles.
var profiles struct {
mu sync.Mutex
m map[string]*Profile
}
var goroutineProfile = &Profile{
name: "goroutine",
count: countGoroutine,
write: writeGoroutine,
}
var threadcreateProfile = &Profile{
name: "threadcreate",
count: countThreadCreate,
write: writeThreadCreate,
}
var heapProfile = &Profile{
name: "heap",
count: countHeap,
write: writeHeap,
}
func lockProfiles() {
profiles.mu.Lock()
if profiles.m == nil {
// Initial built-in profiles.
profiles.m = map[string]*Profile{
"goroutine": goroutineProfile,
"threadcreate": threadcreateProfile,
"heap": heapProfile,
}
}
}
func unlockProfiles() {
profiles.mu.Unlock()
}
// NewProfile creates a new profile with the given name.
// If a profile with that name already exists, NewProfile panics.
// The convention is to use a 'import/path.' prefix to create
// separate name spaces for each package.
func NewProfile(name string) *Profile {
lockProfiles()
defer unlockProfiles()
if name == "" {
panic("pprof: NewProfile with empty name")
}
if profiles.m[name] != nil {
panic("pprof: NewProfile name already in use: " + name)
}
p := &Profile{
name: name,
m: map[interface{}][]uintptr{},
}
profiles.m[name] = p
return p
}
// Lookup returns the profile with the given name, or nil if no such profile exists.
func Lookup(name string) *Profile {
lockProfiles()
defer unlockProfiles()
return profiles.m[name]
}
// Profiles returns a slice of all the known profiles, sorted by name.
func Profiles() []*Profile {
lockProfiles()
defer unlockProfiles()
var all []*Profile
for _, p := range profiles.m {
all = append(all, p)
}
sort.Sort(byName(all))
return all
}
type byName []*Profile
func (x byName) Len() int { return len(x) }
func (x byName) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
func (x byName) Less(i, j int) bool { return x[i].name < x[j].name }
// Name returns this profile's name, which can be passed to Lookup to reobtain the profile.
func (p *Profile) Name() string {
return p.name
}
// Count returns the number of execution stacks currently in the profile.
func (p *Profile) Count() int {
p.mu.Lock()
defer p.mu.Unlock()
if p.count != nil {
return p.count()
}
return len(p.m)
}
// Add adds the current execution stack to the profile, associated with value.
// Add stores value in an internal map, so value must be suitable for use as
// a map key and will not be garbage collected until the corresponding
// call to Remove. Add panics if the profile already contains a stack for value.
//
// The skip parameter has the same meaning as runtime.Caller's skip
// and controls where the stack trace begins. Passing skip=0 begins the
// trace in the function calling Add. For example, given this
// execution stack:
//
// Add
// called from rpc.NewClient
// called from mypkg.Run
// called from main.main
//
// Passing skip=0 begins the stack trace at the call to Add inside rpc.NewClient.
// Passing skip=1 begins the stack trace at the call to NewClient inside mypkg.Run.
//
func (p *Profile) Add(value interface{}, skip int) {
if p.name == "" {
panic("pprof: use of uninitialized Profile")
}
if p.write != nil {
panic("pprof: Add called on built-in Profile " + p.name)
}
stk := make([]uintptr, 32)
n := runtime.Callers(skip+1, stk[:])
p.mu.Lock()
defer p.mu.Unlock()
if p.m[value] != nil {
panic("pprof: Profile.Add of duplicate value")
}
p.m[value] = stk[:n]
}
// Remove removes the execution stack associated with value from the profile.
// It is a no-op if the value is not in the profile.
func (p *Profile) Remove(value interface{}) {
p.mu.Lock()
defer p.mu.Unlock()
delete(p.m, value)
}
// WriteTo writes a pprof-formatted snapshot of the profile to w.
// If a write to w returns an error, WriteTo returns that error.
// Otherwise, WriteTo returns nil.
//
// The debug parameter enables additional output.
// Passing debug=0 prints only the hexadecimal addresses that pprof needs.
// Passing debug=1 adds comments translating addresses to function names
// and line numbers, so that a programmer can read the profile without tools.
//
// The predefined profiles may assign meaning to other debug values;
// for example, when printing the "goroutine" profile, debug=2 means to
// print the goroutine stacks in the same form that a Go program uses
// when dying due to an unrecovered panic.
func (p *Profile) WriteTo(w io.Writer, debug int) error {
if p.name == "" {
panic("pprof: use of zero Profile")
}
if p.write != nil {
return p.write(w, debug)
}
// Obtain consistent snapshot under lock; then process without lock.
var all [][]uintptr
p.mu.Lock()
for _, stk := range p.m {
all = append(all, stk)
}
p.mu.Unlock()
// Map order is non-deterministic; make output deterministic.
sort.Sort(stackProfile(all))
return printCountProfile(w, debug, p.name, stackProfile(all))
}
type stackProfile [][]uintptr
func (x stackProfile) Len() int { return len(x) }
func (x stackProfile) Stack(i int) []uintptr { return x[i] }
func (x stackProfile) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
func (x stackProfile) Less(i, j int) bool {
t, u := x[i], x[j]
for k := 0; k < len(t) && k < len(u); k++ {
if t[k] != u[k] {
return t[k] < u[k]
}
}
return len(t) < len(u)
}
// A countProfile is a set of stack traces to be printed as counts
// grouped by stack trace. There are multiple implementations:
// all that matters is that we can find out how many traces there are
// and obtain each trace in turn.
type countProfile interface {
Len() int
Stack(i int) []uintptr
}
// printCountProfile prints a countProfile at the specified debug level.
func printCountProfile(w io.Writer, debug int, name string, p countProfile) error {
b := bufio.NewWriter(w)
var tw *tabwriter.Writer
w = b
if debug > 0 {
tw = tabwriter.NewWriter(w, 1, 8, 1, '\t', 0)
w = tw
}
fmt.Fprintf(w, "%s profile: total %d\n", name, p.Len())
// Build count of each stack.
var buf bytes.Buffer
key := func(stk []uintptr) string {
buf.Reset()
fmt.Fprintf(&buf, "@")
for _, pc := range stk {
fmt.Fprintf(&buf, " %#x", pc)
}
return buf.String()
}
m := map[string]int{}
n := p.Len()
for i := 0; i < n; i++ {
m[key(p.Stack(i))]++
}
// Print stacks, listing count on first occurrence of a unique stack.
for i := 0; i < n; i++ {
stk := p.Stack(i)
s := key(stk)
if count := m[s]; count != 0 {
fmt.Fprintf(w, "%d %s\n", count, s)
if debug > 0 {
printStackRecord(w, stk, false)
}
delete(m, s)
}
}
if tw != nil {
tw.Flush()
}
return b.Flush()
}
// printStackRecord prints the function + source line information
// for a single stack trace.
func printStackRecord(w io.Writer, stk []uintptr, allFrames bool) {
show := allFrames
for _, pc := range stk {
f := runtime.FuncForPC(pc)
if f == nil {
show = true
fmt.Fprintf(w, "#\t%#x\n", pc)
} else {
file, line := f.FileLine(pc)
name := f.Name()
// Hide runtime.goexit and any runtime functions at the beginning.
// This is useful mainly for allocation traces.
if name == "runtime.goexit" || !show && strings.HasPrefix(name, "runtime.") {
continue
}
show = true
fmt.Fprintf(w, "#\t%#x\t%s+%#x\t%s:%d\n", pc, f.Name(), pc-f.Entry(), file, line)
}
}
if !show {
// We didn't print anything; do it again,
// and this time include runtime functions.
printStackRecord(w, stk, true)
return
}
fmt.Fprintf(w, "\n")
}
// Interface to system profiles.
type byInUseBytes []runtime.MemProfileRecord
func (x byInUseBytes) Len() int { return len(x) }
func (x byInUseBytes) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
func (x byInUseBytes) Less(i, j int) bool { return x[i].InUseBytes() > x[j].InUseBytes() }
// WriteHeapProfile is shorthand for Lookup("heap").WriteTo(w, 0).
// It is preserved for backwards compatibility.
func WriteHeapProfile(w io.Writer) error {
return writeHeap(w, 0)
}
// countHeap returns the number of records in the heap profile.
func countHeap() int {
n, _ := runtime.MemProfile(nil, false)
return n
}
// writeHeapProfile writes the current runtime heap profile to w.
func writeHeap(w io.Writer, debug int) error {
// Find out how many records there are (MemProfile(nil, false)),
// allocate that many records, and get the data.
// There's a race—more records might be added between
......@@ -44,6 +379,16 @@ func WriteHeapProfile(w io.Writer) error {
// Profile grew; try again.
}
sort.Sort(byInUseBytes(p))
b := bufio.NewWriter(w)
var tw *tabwriter.Writer
w = b
if debug > 0 {
tw = tabwriter.NewWriter(w, 1, 8, 1, '\t', 0)
w = tw
}
var total runtime.MemProfileRecord
for i := range p {
r := &p[i]
......@@ -56,78 +401,120 @@ func WriteHeapProfile(w io.Writer) error {
// Technically the rate is MemProfileRate not 2*MemProfileRate,
// but early versions of the C++ heap profiler reported 2*MemProfileRate,
// so that's what pprof has come to expect.
b := bufio.NewWriter(w)
fmt.Fprintf(b, "heap profile: %d: %d [%d: %d] @ heap/%d\n",
fmt.Fprintf(w, "heap profile: %d: %d [%d: %d] @ heap/%d\n",
total.InUseObjects(), total.InUseBytes(),
total.AllocObjects, total.AllocBytes,
2*runtime.MemProfileRate)
for i := range p {
r := &p[i]
fmt.Fprintf(b, "%d: %d [%d: %d] @",
fmt.Fprintf(w, "%d: %d [%d: %d] @",
r.InUseObjects(), r.InUseBytes(),
r.AllocObjects, r.AllocBytes)
for _, pc := range r.Stack() {
fmt.Fprintf(b, " %#x", pc)
fmt.Fprintf(w, " %#x", pc)
}
fmt.Fprintf(w, "\n")
if debug > 0 {
printStackRecord(w, r.Stack(), false)
}
fmt.Fprintf(b, "\n")
}
// Print memstats information too.
// Pprof will ignore, but useful for people.
s := new(runtime.MemStats)
runtime.ReadMemStats(s)
fmt.Fprintf(b, "\n# runtime.MemStats\n")
fmt.Fprintf(b, "# Alloc = %d\n", s.Alloc)
fmt.Fprintf(b, "# TotalAlloc = %d\n", s.TotalAlloc)
fmt.Fprintf(b, "# Sys = %d\n", s.Sys)
fmt.Fprintf(b, "# Lookups = %d\n", s.Lookups)
fmt.Fprintf(b, "# Mallocs = %d\n", s.Mallocs)
fmt.Fprintf(b, "# HeapAlloc = %d\n", s.HeapAlloc)
fmt.Fprintf(b, "# HeapSys = %d\n", s.HeapSys)
fmt.Fprintf(b, "# HeapIdle = %d\n", s.HeapIdle)
fmt.Fprintf(b, "# HeapInuse = %d\n", s.HeapInuse)
fmt.Fprintf(b, "# Stack = %d / %d\n", s.StackInuse, s.StackSys)
fmt.Fprintf(b, "# MSpan = %d / %d\n", s.MSpanInuse, s.MSpanSys)
fmt.Fprintf(b, "# MCache = %d / %d\n", s.MCacheInuse, s.MCacheSys)
fmt.Fprintf(b, "# BuckHashSys = %d\n", s.BuckHashSys)
fmt.Fprintf(b, "# NextGC = %d\n", s.NextGC)
fmt.Fprintf(b, "# PauseNs = %d\n", s.PauseNs)
fmt.Fprintf(b, "# NumGC = %d\n", s.NumGC)
fmt.Fprintf(b, "# EnableGC = %v\n", s.EnableGC)
fmt.Fprintf(b, "# DebugGC = %v\n", s.DebugGC)
fmt.Fprintf(b, "# BySize = Size * (Active = Mallocs - Frees)\n")
fmt.Fprintf(b, "# (Excluding large blocks.)\n")
for _, t := range s.BySize {
if t.Mallocs > 0 {
fmt.Fprintf(b, "# %d * (%d = %d - %d)\n", t.Size, t.Mallocs-t.Frees, t.Mallocs, t.Frees)
}
// Pprof will ignore, but useful for people
if debug > 0 {
s := new(runtime.MemStats)
runtime.ReadMemStats(s)
fmt.Fprintf(w, "\n# runtime.MemStats\n")
fmt.Fprintf(w, "# Alloc = %d\n", s.Alloc)
fmt.Fprintf(w, "# TotalAlloc = %d\n", s.TotalAlloc)
fmt.Fprintf(w, "# Sys = %d\n", s.Sys)
fmt.Fprintf(w, "# Lookups = %d\n", s.Lookups)
fmt.Fprintf(w, "# Mallocs = %d\n", s.Mallocs)
fmt.Fprintf(w, "# HeapAlloc = %d\n", s.HeapAlloc)
fmt.Fprintf(w, "# HeapSys = %d\n", s.HeapSys)
fmt.Fprintf(w, "# HeapIdle = %d\n", s.HeapIdle)
fmt.Fprintf(w, "# HeapInuse = %d\n", s.HeapInuse)
fmt.Fprintf(w, "# Stack = %d / %d\n", s.StackInuse, s.StackSys)
fmt.Fprintf(w, "# MSpan = %d / %d\n", s.MSpanInuse, s.MSpanSys)
fmt.Fprintf(w, "# MCache = %d / %d\n", s.MCacheInuse, s.MCacheSys)
fmt.Fprintf(w, "# BuckHashSys = %d\n", s.BuckHashSys)
fmt.Fprintf(w, "# NextGC = %d\n", s.NextGC)
fmt.Fprintf(w, "# PauseNs = %d\n", s.PauseNs)
fmt.Fprintf(w, "# NumGC = %d\n", s.NumGC)
fmt.Fprintf(w, "# EnableGC = %v\n", s.EnableGC)
fmt.Fprintf(w, "# DebugGC = %v\n", s.DebugGC)
}
if tw != nil {
tw.Flush()
}
return b.Flush()
}
// WriteThreadProfile writes a pprof-formatted thread creation profile to w.
// If a write to w returns an error, WriteThreadProfile returns that error.
// Otherwise, WriteThreadProfile returns nil.
func WriteThreadProfile(w io.Writer) error {
// Find out how many records there are (ThreadProfile(nil)),
// countThreadCreate returns the size of the current ThreadCreateProfile.
func countThreadCreate() int {
n, _ := runtime.ThreadCreateProfile(nil)
return n
}
// writeThreadCreate writes the current runtime ThreadCreateProfile to w.
func writeThreadCreate(w io.Writer, debug int) error {
return writeRuntimeProfile(w, debug, "threadcreate", runtime.ThreadCreateProfile)
}
// countGoroutine returns the number of goroutines.
func countGoroutine() int {
return runtime.NumGoroutine()
}
// writeGoroutine writes the current runtime GoroutineProfile to w.
func writeGoroutine(w io.Writer, debug int) error {
if debug >= 2 {
return writeGoroutineStacks(w)
}
return writeRuntimeProfile(w, debug, "goroutine", runtime.GoroutineProfile)
}
func writeGoroutineStacks(w io.Writer) error {
// We don't know how big the buffer needs to be to collect
// all the goroutines. Start with 1 MB and try a few times, doubling each time.
// Give up and use a truncated trace if 64 MB is not enough.
buf := make([]byte, 1<<20)
for i := 0; ; i++ {
n := runtime.Stack(buf, true)
if n < len(buf) {
buf = buf[:n]
break
}
if len(buf) >= 64<<20 {
// Filled 64 MB - stop there.
break
}
buf = make([]byte, 2*len(buf))
}
_, err := w.Write(buf)
return err
}
func writeRuntimeProfile(w io.Writer, debug int, name string, fetch func([]runtime.StackRecord) (int, bool)) error {
// Find out how many records there are (fetch(nil)),
// allocate that many records, and get the data.
// There's a race—more records (threads) might be added between
// There's a race—more records might be added between
// the two calls—so allocate a few extra records for safety
// and also try again if we're very unlucky.
// The loop should only execute one iteration in the common case.
var p []runtime.ThreadProfileRecord
n, ok := runtime.ThreadProfile(nil)
var p []runtime.StackRecord
n, ok := fetch(nil)
for {
// Allocate room for a slightly bigger profile,
// in case a few more entries have been added
// since the call to ThreadProfile.
p = make([]runtime.ThreadProfileRecord, n+10)
n, ok = runtime.ThreadProfile(p)
p = make([]runtime.StackRecord, n+10)
n, ok = fetch(p)
if ok {
p = p[0:n]
break
......@@ -135,19 +522,14 @@ func WriteThreadProfile(w io.Writer) error {
// Profile grew; try again.
}
b := bufio.NewWriter(w)
fmt.Fprintf(b, "thread creation profile: %d threads\n", n)
for i := range p {
r := &p[i]
fmt.Fprintf(b, "@")
for _, pc := range r.Stack() {
fmt.Fprintf(b, " %#x", pc)
}
fmt.Fprintf(b, "\n")
}
return b.Flush()
return printCountProfile(w, debug, name, runtimeProfile(p))
}
type runtimeProfile []runtime.StackRecord
func (p runtimeProfile) Len() int { return len(p) }
func (p runtimeProfile) Stack(i int) []uintptr { return p[i].Stack() }
var cpu struct {
sync.Mutex
profiling bool
......
src/pkg/text/tabwriter/tabwriter_test.go
View file @ ebae73bb
......@@ -2,11 +2,12 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tabwriter
package tabwriter_test
import (
"io"
"testing"
. "text/tabwriter"
)
type buffer struct {
......
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