net/http: use runtime.Stack instead of runtime/debug.Stack

Fixes #4060.

2012/11/21 19:51:34 http: panic serving 127.0.0.1:47139: Kaaarn!
goroutine 7 [running]:
net/http.func·004(0x7f330807ffb0, 0x7f330807f100)
	/home/dfc/go/src/pkg/net/http/server.go:615 +0xa7
----- stack segment boundary -----
main.(*httpHandler).ServeHTTP()
	/home/dfc/src/httppanic.go:16 +0x53
net/http.(*conn).serve(0xc200090240, 0x0)
	/home/dfc/go/src/pkg/net/http/server.go:695 +0x55d
created by net/http.(*Server).Serve
	/home/dfc/go/src/pkg/net/http/server.go:1119 +0x36d

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/6846085

diff --git a/src/pkg/net/http/server.go b/src/pkg/net/http/server.go
index 805e0737a974fc41e0353eb68f6d1b004f767b4c..3a4d61c21394be0350e718325bba4e39f6749d7f 100644 (file)
--- a/src/pkg/net/http/server.go
+++ b/src/pkg/net/http/server.go
@@ -11,7 +11,6 @@ package http
 
 import (
        "bufio"
-       "bytes"
        "crypto/tls"
        "errors"
        "fmt"
@@ -21,7 +20,7 @@ import (
        "net"
        "net/url"
        "path"
-       "runtime/debug"
+       "runtime"
        "strconv"
        "strings"
        "sync"
@@ -610,10 +609,10 @@ func (c *conn) serve() {
                        return
                }
 
-               var buf bytes.Buffer
-               fmt.Fprintf(&buf, "http: panic serving %v: %v\n", c.remoteAddr, err)
-               buf.Write(debug.Stack())
-               log.Print(buf.String())
+               const size = 4096
+               buf := make([]byte, size)
+               buf = buf[:runtime.Stack(buf, false)]
+               log.Printf("http: panic serving %v: %v\n%s", c.remoteAddr, err, buf)
 
                if c.rwc != nil { // may be nil if connection hijacked
                        c.rwc.Close()