race when close redcon

[agfn]

redcon version: 1.4.4

POC

package main

import (
	"context"
	"log"
	"strings"

	"github.com/go-redis/redis/v9"
	"github.com/tidwall/redcon"
)

func main() {
	redcon := redcon.NewServerNetwork("tcp", "127.0.0.1:12345",
		func(conn redcon.Conn, cmd redcon.Command) {
			switch strings.ToLower(string(cmd.Args[0])) {
			case "set":
				log.Println(string(cmd.Args[1]), string(cmd.Args[2]))
				conn.WriteString("OK")
			default:
				log.Println("cmd not implemented: ", string(cmd.Args[0]))
				conn.WriteError("ERR unknown command '" + string(cmd.Args[0]) + "'")
			}

		}, nil, nil,
	)
	ch := make(chan error)
	go func() {
		redcon.ListenServeAndSignal(ch)
	}()
	if err := <-ch; err != nil {
		log.Fatal(err)
	}

	// create redis client, test set command
	client := redis.NewClient(&redis.Options{
		Addr:    redcon.Addr().String(),
		Network: redcon.Addr().Network(),
	})
	r := client.Set(context.Background(), "tmp", "test", 0)
	if r.Err() != nil {
		log.Fatal(r.Err())
	}
	if err := client.Close(); err != nil {
		log.Fatal(err)
	}

	// close redcon (race)
	if err := redcon.Close(); err != nil {
		log.Fatal(err)
	}
}

// go run -race poc.go

The race occurs when closing redcon while the handle function is not finished (invoking c.wr.Flush, but without lock).

[tidwall]

I believe this to be fixed in v1.4.5.