diff options
Diffstat (limited to 'vendor/github.com/google/gops/agent/agent.go')
-rw-r--r-- | vendor/github.com/google/gops/agent/agent.go | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/vendor/github.com/google/gops/agent/agent.go b/vendor/github.com/google/gops/agent/agent.go new file mode 100644 index 00000000..57083918 --- /dev/null +++ b/vendor/github.com/google/gops/agent/agent.go @@ -0,0 +1,237 @@ +// Copyright 2016 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 agent provides hooks programs can register to retrieve +// diagnostics data by using gops. +package agent + +import ( + "fmt" + "io" + "io/ioutil" + "net" + "os" + gosignal "os/signal" + "runtime" + "runtime/pprof" + "runtime/trace" + "strconv" + "sync" + "time" + + "bufio" + + "github.com/google/gops/internal" + "github.com/google/gops/signal" + "github.com/kardianos/osext" +) + +const defaultAddr = "127.0.0.1:0" + +var ( + mu sync.Mutex + portfile string + listener net.Listener + + units = []string{" bytes", "KB", "MB", "GB", "TB", "PB"} +) + +// Options allows configuring the started agent. +type Options struct { + // Addr is the host:port the agent will be listening at. + // Optional. + Addr string + + // NoShutdownCleanup tells the agent not to automatically cleanup + // resources if the running process receives an interrupt. + // Optional. + NoShutdownCleanup bool +} + +// Listen starts the gops agent on a host process. Once agent started, users +// can use the advanced gops features. The agent will listen to Interrupt +// signals and exit the process, if you need to perform further work on the +// Interrupt signal use the options parameter to configure the agent +// accordingly. +// +// Note: The agent exposes an endpoint via a TCP connection that can be used by +// any program on the system. Review your security requirements before starting +// the agent. +func Listen(opts *Options) error { + mu.Lock() + defer mu.Unlock() + + if opts == nil { + opts = &Options{} + } + if portfile != "" { + return fmt.Errorf("gops: agent already listening at: %v", listener.Addr()) + } + + gopsdir, err := internal.ConfigDir() + if err != nil { + return err + } + err = os.MkdirAll(gopsdir, os.ModePerm) + if err != nil { + return err + } + if !opts.NoShutdownCleanup { + gracefulShutdown() + } + + addr := opts.Addr + if addr == "" { + addr = defaultAddr + } + ln, err := net.Listen("tcp", addr) + if err != nil { + return err + } + listener = ln + port := listener.Addr().(*net.TCPAddr).Port + portfile = fmt.Sprintf("%s/%d", gopsdir, os.Getpid()) + err = ioutil.WriteFile(portfile, []byte(strconv.Itoa(port)), os.ModePerm) + if err != nil { + return err + } + + go listen() + return nil +} + +func listen() { + buf := make([]byte, 1) + for { + fd, err := listener.Accept() + if err != nil { + fmt.Fprintf(os.Stderr, "gops: %v", err) + if netErr, ok := err.(net.Error); ok && !netErr.Temporary() { + break + } + continue + } + if _, err := fd.Read(buf); err != nil { + fmt.Fprintf(os.Stderr, "gops: %v", err) + continue + } + if err := handle(fd, buf); err != nil { + fmt.Fprintf(os.Stderr, "gops: %v", err) + continue + } + fd.Close() + } +} + +func gracefulShutdown() { + c := make(chan os.Signal, 1) + gosignal.Notify(c, os.Interrupt) + go func() { + // cleanup the socket on shutdown. + <-c + Close() + os.Exit(1) + }() +} + +// Close closes the agent, removing temporary files and closing the TCP listener. +// If no agent is listening, Close does nothing. +func Close() { + mu.Lock() + defer mu.Unlock() + + if portfile != "" { + os.Remove(portfile) + portfile = "" + } + if listener != nil { + listener.Close() + } +} + +func formatBytes(val uint64) string { + var i int + var target uint64 + for i = range units { + target = 1 << uint(10*(i+1)) + if val < target { + break + } + } + if i > 0 { + return fmt.Sprintf("%0.2f%s (%d bytes)", float64(val)/(float64(target)/1024), units[i], val) + } + return fmt.Sprintf("%d bytes", val) +} + +func handle(conn io.Writer, msg []byte) error { + switch msg[0] { + case signal.StackTrace: + return pprof.Lookup("goroutine").WriteTo(conn, 2) + case signal.GC: + runtime.GC() + _, err := conn.Write([]byte("ok")) + return err + case signal.MemStats: + var s runtime.MemStats + runtime.ReadMemStats(&s) + fmt.Fprintf(conn, "alloc: %v\n", formatBytes(s.Alloc)) + fmt.Fprintf(conn, "total-alloc: %v\n", formatBytes(s.TotalAlloc)) + fmt.Fprintf(conn, "sys: %v\n", formatBytes(s.Sys)) + fmt.Fprintf(conn, "lookups: %v\n", s.Lookups) + fmt.Fprintf(conn, "mallocs: %v\n", s.Mallocs) + fmt.Fprintf(conn, "frees: %v\n", s.Frees) + fmt.Fprintf(conn, "heap-alloc: %v\n", formatBytes(s.HeapAlloc)) + fmt.Fprintf(conn, "heap-sys: %v\n", formatBytes(s.HeapSys)) + fmt.Fprintf(conn, "heap-idle: %v\n", formatBytes(s.HeapIdle)) + fmt.Fprintf(conn, "heap-in-use: %v\n", formatBytes(s.HeapInuse)) + fmt.Fprintf(conn, "heap-released: %v\n", formatBytes(s.HeapReleased)) + fmt.Fprintf(conn, "heap-objects: %v\n", s.HeapObjects) + fmt.Fprintf(conn, "stack-in-use: %v\n", formatBytes(s.StackInuse)) + fmt.Fprintf(conn, "stack-sys: %v\n", formatBytes(s.StackSys)) + fmt.Fprintf(conn, "next-gc: when heap-alloc >= %v\n", formatBytes(s.NextGC)) + lastGC := "-" + if s.LastGC != 0 { + lastGC = fmt.Sprint(time.Unix(0, int64(s.LastGC))) + } + fmt.Fprintf(conn, "last-gc: %v\n", lastGC) + fmt.Fprintf(conn, "gc-pause: %v\n", time.Duration(s.PauseTotalNs)) + fmt.Fprintf(conn, "num-gc: %v\n", s.NumGC) + fmt.Fprintf(conn, "enable-gc: %v\n", s.EnableGC) + fmt.Fprintf(conn, "debug-gc: %v\n", s.DebugGC) + case signal.Version: + fmt.Fprintf(conn, "%v\n", runtime.Version()) + case signal.HeapProfile: + pprof.WriteHeapProfile(conn) + case signal.CPUProfile: + if err := pprof.StartCPUProfile(conn); err != nil { + return err + } + time.Sleep(30 * time.Second) + pprof.StopCPUProfile() + case signal.Stats: + fmt.Fprintf(conn, "goroutines: %v\n", runtime.NumGoroutine()) + fmt.Fprintf(conn, "OS threads: %v\n", pprof.Lookup("threadcreate").Count()) + fmt.Fprintf(conn, "GOMAXPROCS: %v\n", runtime.GOMAXPROCS(0)) + fmt.Fprintf(conn, "num CPU: %v\n", runtime.NumCPU()) + case signal.BinaryDump: + path, err := osext.Executable() + if err != nil { + return err + } + f, err := os.Open(path) + if err != nil { + return err + } + defer f.Close() + + _, err = bufio.NewReader(f).WriteTo(conn) + return err + case signal.Trace: + trace.Start(conn) + time.Sleep(5 * time.Second) + trace.Stop() + } + return nil +} |