Open
Description
What version of Go are you using (go version
)?
$ go version go1.21.0 linux/arm64
Does this issue reproduce with the latest release?
Yes
What operating system and processor architecture are you using (go env
)?
go env
Output
$ go env GO111MODULE='' GOARCH='arm64' GOBIN='' GOCACHE='/home/parallels/.cache/go-build' GOENV='/home/parallels/.config/go/env' GOEXE='' GOEXPERIMENT='' GOFLAGS='' GOHOSTARCH='arm64' GOHOSTOS='linux' GOINSECURE='' GOMODCACHE='/home/parallels/src/go/pkg/mod' GONOPROXY='' GONOSUMDB='' GOOS='linux' GOPATH='/home/parallels/src/go' GOPRIVATE='' GOPROXY='https://proxy.golang.org,direct' GOROOT='/home/parallels/bin/go1.21ex' GOSUMDB='sum.golang.org' GOTMPDIR='' GOTOOLCHAIN='auto' GOTOOLDIR='/home/parallels/bin/go1.21ex/pkg/tool/linux_arm64' GOVCS='' GOVERSION='go1.21.0' GCCGO='gccgo' AR='ar' CC='gcc' CXX='g++' CGO_ENABLED='1' GOMOD='/home/parallels/src/go/src/github.com/libp2p/go-libp2p/go.mod' GOWORK='' CGO_CFLAGS='-O2 -g' CGO_CPPFLAGS='' CGO_CXXFLAGS='-O2 -g' CGO_FFLAGS='-O2 -g' CGO_LDFLAGS='-O2 -g' PKG_CONFIG='pkg-config' GOGCCFLAGS='-fPIC -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build618110419=/tmp/go-build -gno-record-gcc-switches'
What did you do?
I created two UDP sockets, and send UDP datagrams from one to the other, and vice versa:
func newUDPConn(t *testing.T) *net.UDPConn {
addr, err := net.ResolveUDPAddr("udp", "localhost:0")
if err != nil {
t.Fatal(err)
}
conn, err := net.ListenUDP("udp", addr)
if err != nil {
t.Fatal(err)
}
t.Cleanup(func() { conn.Close() })
return conn
}
func TestUDPSending(t *testing.T) {
c1 := newUDPConn(t)
c2 := newUDPConn(t)
const num = 1000
done := make(chan struct{}, 2)
var failed1, failed2 bool
go func() {
defer func() { done <- struct{}{} }()
for i := 0; i < num; i++ {
_, _, err := c1.WriteMsgUDP(make([]byte, 1000), nil, c2.LocalAddr().(*net.UDPAddr))
if err != nil {
failed1 = true
t.Logf("c1 send failed %d: %v\n", i, err)
}
time.Sleep(200 * time.Microsecond)
}
}()
go func() {
defer func() { done <- struct{}{} }()
for i := 0; i < num; i++ {
_, _, err := c2.WriteMsgUDP(make([]byte, 1000), nil, c1.LocalAddr().(*net.UDPAddr))
if err != nil {
failed2 = true
t.Logf("c2 send failed %d: %v\n", i, err)
}
time.Sleep(200 * time.Microsecond)
}
}()
<-done
<-done
if failed1 || failed2 {
t.Fail()
}
}
What did you expect to see?
I expected UDP datagrams to be sent on both sockets.
What did you see instead?
More often than not, this test fails on Linux:
c1 send failed 0: write udp 127.0.0.1:47716->127.0.0.1:34183: sendmsg: operation not permitted
It's either the first or the second connection that fails, but if there's a failure, it's always only the first call that fails. All subsequent calls complete successfully.
On macOS, this code doesn't produce any errors.