Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

net/http: Server.Close does defer Lock #17878

Closed
peter-mogensen opened this issue Nov 10, 2016 · 3 comments

Comments

Projects
None yet
3 participants
@peter-mogensen
Copy link

commented Nov 10, 2016

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

Go master HEAD 8d0c105

What operating system and processor architecture are you using (go env)?

GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH=""
GORACE=""
GOROOT="/usr/lib/go"
GOTOOLDIR="/usr/lib/go/pkg/tool/linux_amd64"
GO15VENDOREXPERIMENT="1"
CC="gcc"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0"
CXX="g++"
CGO_ENABLED="1"

What did you do?

package main

import (
	"log"
	"fmt"
	"time"
	"net"
	"net/http"
)

type server3 struct {
	http.Server
}

func (s *server3) Serve(l net.Listener) error {
	fmt.Println("Serving")
	time.Sleep(time.Second)
	return s.Server.Serve(l)
}

// naming is a bitch
func (s *server3) Shutdown() {
	fmt.Println("Closing")
	s.Close()
}

func main() {

	srv := &server3{}
	srvEnd :=  make(chan error)


	for {
		l, err := net.Listen("tcp","")
		if err != nil {
			log.Fatal(err)
		}
		
		go func() {
			err := srv.Serve(l)
			srvEnd <- err 
		}()

		time.Sleep(time.Second)
		
		srv.Shutdown()

		fmt.Println("Close done")
		
		err = <- srvEnd
		
		fmt.Println(err)
	}
}

What did you expect to see?

Serving
Closing
Close done
^C

What did you see instead?

Serving
Closing
^C

@peter-mogensen

This comment has been minimized.

Copy link
Author

commented Nov 10, 2016

$ git diff
diff --git a/src/net/http/server.go b/src/net/http/server.go
index 0959ac6..d78fd71 100644
--- a/src/net/http/server.go
+++ b/src/net/http/server.go
@@ -2362,7 +2362,7 @@ func (s *Server) closeDoneChanLocked() {
 // regardless of their state. For a graceful shutdown, use Shutdown.
 func (s *Server) Close() error {
        s.mu.Lock()
-       defer s.mu.Lock()
+       defer s.mu.Unlock()
        s.closeDoneChanLocked()
        err := s.closeListenersLocked()
        for c := range s.activeConn {

@bradfitz bradfitz self-assigned this Nov 10, 2016

@bradfitz bradfitz changed the title http.Server.Close() does defer s.mu.Lock() ... instead of Unlock() net/http: Server.Close does defer Lock Nov 10, 2016

@bradfitz

This comment has been minimized.

Copy link
Member

commented Nov 10, 2016

That's a very wordy bug report. Thanks to @peter-mogensen for summarizing.

@bradfitz bradfitz added this to the Go1.8 milestone Nov 10, 2016

@gopherbot

This comment has been minimized.

Copy link

commented Nov 10, 2016

CL https://golang.org/cl/33026 mentions this issue.

@gopherbot gopherbot closed this in 8cd5561 Nov 10, 2016

@golang golang locked and limited conversation to collaborators Nov 10, 2017

Sign up for free to subscribe to this conversation on GitHub. Already have an account? Sign in.
You can’t perform that action at this time.