Your TCP FIN is still in transit or not yet processed by the other TCP stack when you issue the first write.
TCP is not synchronous even if running on same host. Janne Snabb sn...@epipe.com On 2018-04-10 17:58, pierspowlesl...@gmail.com wrote: > Hi > > I'm trying to understand what is going on under the hood here. > > I would expect a net.Conn after being closed from the far side, to issue > an error if the near side then tries to write to it. On my local machine > an error is returned on the second write, on the go playground all > writes succeed. > > The test is shown below and is also here > - https://play.golang.org/p/EFYX_ZehMKs > > Thanks for any insight, > > Piers > > | > func TestDetectClosedConnectionWhenWriting(t *testing.T) { > listener, err := net.Listen("tcp", ":0") > if err != nil { > t.Fatal(err) > } > > wait := make(chan struct{}) > go func() { > conn, err := listener.Accept() > if err != nil { > t.Fatal(err) > } > err = conn.Close() > if err != nil { > t.Fatal(err) > } > wait <- struct{}{} > }() > > conn, err := net.Dial("tcp", listener.Addr().String()) > if err != nil { > t.Fatal(err) > } > <-wait > for i := 0; i < 100; i++ { > println(i) > _, err = conn.Write([]byte("b")) > if err != nil { > break > } > } > if err == nil { > t.Fatal("expecting error to be returned when writing") > } > t.Fatal("expecting error to be a permanent net.OpError") > } > > | > > > > -- > You received this message because you are subscribed to the Google > Groups "golang-nuts" group. > To unsubscribe from this group and stop receiving emails from it, send > an email to golang-nuts+unsubscr...@googlegroups.com > <mailto:golang-nuts+unsubscr...@googlegroups.com>. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
