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Diffstat (limited to 'libgo/go/net/http/pprof/pprof.go')
-rw-r--r--libgo/go/net/http/pprof/pprof.go133
1 files changed, 133 insertions, 0 deletions
diff --git a/libgo/go/net/http/pprof/pprof.go b/libgo/go/net/http/pprof/pprof.go
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+++ b/libgo/go/net/http/pprof/pprof.go
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+// Copyright 2010 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 serves via its HTTP server runtime profiling data
+// in the format expected by the pprof visualization tool.
+// For more information about pprof, see
+// http://code.google.com/p/google-perftools/.
+//
+// The package is typically only imported for the side effect of
+// registering its HTTP handlers.
+// The handled paths all begin with /debug/pprof/.
+//
+// To use pprof, link this package into your program:
+// import _ "http/pprof"
+//
+// Then use the pprof tool to look at the heap profile:
+//
+// pprof http://localhost:6060/debug/pprof/heap
+//
+// Or to look at a 30-second CPU profile:
+//
+// pprof http://localhost:6060/debug/pprof/profile
+//
+package pprof
+
+import (
+ "bufio"
+ "bytes"
+ "fmt"
+ "io"
+ "net/http"
+ "os"
+ "runtime"
+ "runtime/pprof"
+ "strconv"
+ "strings"
+ "time"
+)
+
+func init() {
+ 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))
+}
+
+// Cmdline responds with the running program's
+// command line, with arguments separated by NUL bytes.
+// The package initialization registers it as /debug/pprof/cmdline.
+func Cmdline(w http.ResponseWriter, r *http.Request) {
+ w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+ 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)
+}
+
+// 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) {
+ sec, _ := strconv.Atoi64(r.FormValue("seconds"))
+ if sec == 0 {
+ sec = 30
+ }
+
+ // Set Content Type assuming StartCPUProfile will work,
+ // because if it does it starts writing.
+ w.Header().Set("Content-Type", "application/octet-stream")
+ if err := pprof.StartCPUProfile(w); err != nil {
+ // StartCPUProfile failed, so no writes yet.
+ // Can change header back to text content
+ // and send error code.
+ w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+ w.WriteHeader(http.StatusInternalServerError)
+ fmt.Fprintf(w, "Could not enable CPU profiling: %s\n", err)
+ return
+ }
+ time.Sleep(sec * 1e9)
+ pprof.StopCPUProfile()
+}
+
+// Symbol looks up the program counters listed in the request,
+// responding with a table mapping program counters to function names.
+// The package initialization registers it as /debug/pprof/symbol.
+func Symbol(w http.ResponseWriter, r *http.Request) {
+ w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+
+ // We have to read the whole POST body before
+ // writing any output. Buffer the output here.
+ var buf bytes.Buffer
+
+ // We don't know how many symbols we have, but we
+ // do have symbol information. Pprof only cares whether
+ // this number is 0 (no symbols available) or > 0.
+ fmt.Fprintf(&buf, "num_symbols: 1\n")
+
+ var b *bufio.Reader
+ if r.Method == "POST" {
+ b = bufio.NewReader(r.Body)
+ } else {
+ b = bufio.NewReader(strings.NewReader(r.URL.RawQuery))
+ }
+
+ for {
+ word, err := b.ReadSlice('+')
+ if err == nil {
+ word = word[0 : len(word)-1] // trim +
+ }
+ pc, _ := strconv.Btoui64(string(word), 0)
+ if pc != 0 {
+ f := runtime.FuncForPC(uintptr(pc))
+ if f != nil {
+ fmt.Fprintf(&buf, "%#x %s\n", pc, f.Name())
+ }
+ }
+
+ // Wait until here to check for err; the last
+ // symbol will have an err because it doesn't end in +.
+ if err != nil {
+ if err != io.EOF {
+ fmt.Fprintf(&buf, "reading request: %v\n", err)
+ }
+ break
+ }
+ }
+
+ w.Write(buf.Bytes())
+}