net: deflake TestListenerClose

Fixes #14124.

Change-Id: I9a694c402e613d27701e7e41640af357c373edea
Reviewed-on: https://go-review.googlesource.com/18959
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

diff --git a/src/net/net_test.go b/src/net/net_test.go
index 6dcfc2190e03c5675a75d5952f7a5fcefbe9fbcf..cd62b4373ebb1aafc66728432e19d808ba32672c 100644 (file)
--- a/src/net/net_test.go
+++ b/src/net/net_test.go
@@ -9,6 +9,7 @@ import (
        "os"
        "runtime"
        "testing"
+       "time"
 )
 
 func TestCloseRead(t *testing.T) {
@@ -209,6 +210,7 @@ func TestListenerClose(t *testing.T) {
                        defer os.Remove(ln.Addr().String())
                }
 
+               dst := ln.Addr().String()
                if err := ln.Close(); err != nil {
                        if perr := parseCloseError(err); perr != nil {
                                t.Error(perr)
@@ -222,9 +224,24 @@ func TestListenerClose(t *testing.T) {
                }
 
                if network == "tcp" {
-                       cc, err := Dial("tcp", ln.Addr().String())
+                       // We will have two TCP FSMs inside the
+                       // kernel here. There's no guarantee that a
+                       // signal comes from the far end FSM will be
+                       // delivered immediately to the near end FSM,
+                       // especially on the platforms that allow
+                       // multiple consumer threads to pull pending
+                       // established connections at the same time by
+                       // enabling SO_REUSEPORT option such as Linux,
+                       // DragonFly BSD. So we need to give some time
+                       // quantum to the kernel.
+                       //
+                       // Note that net.inet.tcp.reuseport_ext=1 by
+                       // default on DragonFly BSD.
+                       time.Sleep(time.Millisecond)
+
+                       cc, err := Dial("tcp", dst)
                        if err == nil {
-                               t.Error("Dial to closed TCP listener succeeeded.")
+                               t.Error("Dial to closed TCP listener succeeded.")
                                cc.Close()
                        }
                }
@@ -272,6 +289,9 @@ func TestListenCloseListen(t *testing.T) {
                }
                addr := ln.Addr().String()
                if err := ln.Close(); err != nil {
+                       if perr := parseCloseError(err); perr != nil {
+                               t.Error(perr)
+                       }
                        t.Fatal(err)
                }
                ln, err = Listen("tcp", addr)