add experimental pprof support

agent/agent.go

@@ -12,6 +12,7 @@ import (
 	"os"
 	gosignal "os/signal"
 	"runtime"
+	"runtime/pprof"
 
 	"github.com/google/gops/signal"
 )
@@ -30,6 +31,7 @@ func Start() error {
 	if err != nil {
 		return err
 	}
+	fmt.Println(sock)
 
 	c := make(chan os.Signal, 1)
 	gosignal.Notify(c, os.Interrupt)
@@ -98,6 +100,10 @@ func handle(conn net.Conn, msg []byte) error {
 		fmt.Fprintf(conn, "debug-gc: %v\n", s.DebugGC)
 	case signal.Version:
 		fmt.Fprintf(conn, "%v\n", runtime.Version())
+	case signal.HeapProfile:
+		pprof.Lookup("heap").WriteTo(conn, 1)
+	case signal.CPUProfile:
+		panic("not implemented")
 	}
 	return nil
 }

cmd.go

@@ -5,6 +5,10 @@ import (
 	"io/ioutil"
 	"net"
 
+	"os/exec"
+
+	"os"
+
 	"github.com/google/gops/signal"
 )
 
@@ -13,6 +17,7 @@ var cmds = map[string](func(pid int) error){
 	"gc":       gc,
 	"memstats": memStats,
 	"version":  version,
+	"pprof":    pprof,
 }
 
 func stackTrace(pid int) error {
@@ -47,6 +52,26 @@ func version(pid int) error {
 	return nil
 }
 
+func pprof(pid int) error {
+	out, err := cmd(pid, signal.HeapProfile)
+	if err != nil {
+		return err
+	}
+	tmpfile, err := ioutil.TempFile("", "heap-profile")
+	if err != nil {
+		return err
+	}
+	if err := ioutil.WriteFile(tmpfile.Name(), []byte(out), 0); err != nil {
+		return err
+	}
+	cmd := exec.Command("go", "tool", "pprof", tmpfile.Name())
+	cmd.Env = os.Environ()
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	return cmd.Run()
+}
+
 func cmd(pid int, c byte) (string, error) {
 	sock := fmt.Sprintf("/tmp/gops%d.sock", pid)
 	conn, err := net.Dial("unix", sock)

signal/signal.go

@@ -17,4 +17,10 @@ const (
 
 	// Version prints the Go version.
 	Version = byte(0x4)
+
+	// HeapProfile starts `go tool pprof`` with the current memory profile.
+	HeapProfile = byte(0x5)
+
+	// CPUProfile starts `go tool pprof` with the current CPU profile
+	CPUProfile = byte(0x6)
 )