diff options
Diffstat (limited to 'libgo/go/net/http/pprof/pprof.go')
-rw-r--r-- | libgo/go/net/http/pprof/pprof.go | 133 |
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 new file mode 100644 index 0000000..c0327a9 --- /dev/null +++ b/libgo/go/net/http/pprof/pprof.go @@ -0,0 +1,133 @@ +// 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()) +} |