Closed as not planned
Description
Go version
go version go1.24.4 linux/amd64
Output of go env in your module/workspace:
AR='ar'
CC='gcc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='g++'
GCCGO='gccgo'
GO111MODULE=''
GOAMD64='v1'
GOARCH='amd64'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/home/fuhz/.cache/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/home/fuhz/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build1848721630=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/home/fuhz/src/udpserver/go.mod'
GOMODCACHE='/home/fuhz/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/home/fuhz/go'
GOPRIVATE=''
GOPROXY='https://goproxy.cn,direct'
GOROOT='/opt/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/home/fuhz/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/opt/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.24.4'
GOWORK=''
PKG_CONFIG='pkg-config'What did you do?
I write a udp server to register clients incoming, and send list of clients.
my server main code:
addr, err := net.ResolveUDPAddr("udp4", fmt.Sprintf(":%v", flag.Arg(0)))
if err != nil {
panic(err)
}
var buffer [1024]byte
var store = list.New()
store.Init()
c, err := net.ListenUDP("udp4", addr)
if err != nil {
panic(err)
}
defer c.Close()
for {
log.Println("listen udp:", c.LocalAddr().String())
c.SetDeadline(time.Now().Add(time.Second * 30))
n, raddr, err := c.ReadFrom(buffer[:])
if n == 0 || err != nil {
break
}
if !contains(store, raddr.String()) {
store.PushBack(raddr.String())
}
log.Println(string(buffer[:n]), raddr.String())
c.WriteTo([]byte("from="+c.LocalAddr().String()), raddr)
if string(buffer[:n]) == "list" {
res := []string{}
p := store.Front()
for {
if p == nil {
break
}
res = append(res, p.Value.(string))
p = p.Next()
}
data := strings.Join(res, ";")
c.WriteTo([]byte("list="+data), raddr)
log.Println("list")
}
}
my client main code:
conn, err := net.DialUDP("udp", nil, uaddr)
if err != nil {
return err
}
once.Do(func() {
go udpLoop(c)
})
n, err := conn.Write([]byte(msg))
if err != nil {
return err
}
if n == 0 {
return errors.New("send null")
}
return nil
}
func udpLoop(c *net.UDPConn) {
var buffer [1024]byte
for {
n, raddr, err := c.ReadFromUDP(buffer[:])
if n == 0 || err != nil {
break
}
fmt.Printf("%v:%v", string(buffer[:n]), raddr.String())
}
}
What did you see happen?
The server only reply the first client.
The message from second client can not be received.
Seriously, after the second client send the message, the server seems to work full speed and blocked, the cpu work 100%, and the deadline time is not work.
What did you expect to see?
The server should reply every client incoming. The CPU load should be very low.