log/syslog: fix race in test between channel close and accept.

Fixes #4769.

R=golang-dev, dave, adg, bradfitz
CC=fullung, golang-dev
https://golang.org/cl/7322089

diff --git a/src/pkg/log/syslog/syslog_test.go b/src/pkg/log/syslog/syslog_test.go
index 2808622e2212d546af8cbedc3bd38b94a4d71641..ec4525190f4945b006f2c0106bf21116d5422fdc 100644 (file)
--- a/src/pkg/log/syslog/syslog_test.go
+++ b/src/pkg/log/syslog/syslog_test.go
@@ -51,7 +51,6 @@ func runStreamSyslog(l net.Listener, done chan<- string, wg *sync.WaitGroup) {
                var c net.Conn
                var err error
                if c, err = l.Accept(); err != nil {
-                       fmt.Print(err)
                        return
                }
                wg.Add(1)
@@ -71,7 +70,7 @@ func runStreamSyslog(l net.Listener, done chan<- string, wg *sync.WaitGroup) {
        }
 }
 
-func startServer(n, la string, done chan<- string) (addr string, wg *sync.WaitGroup) {
+func startServer(n, la string, done chan<- string) (addr string, sock io.Closer, wg *sync.WaitGroup) {
        if n == "udp" || n == "tcp" {
                la = "127.0.0.1:0"
        } else {
@@ -95,6 +94,7 @@ func startServer(n, la string, done chan<- string) (addr string, wg *sync.WaitGr
                        log.Fatalf("startServer failed: %v", e)
                }
                addr = l.LocalAddr().String()
+               sock = l
                wg.Add(1)
                go func() {
                        defer wg.Done()
@@ -106,7 +106,12 @@ func startServer(n, la string, done chan<- string) (addr string, wg *sync.WaitGr
                        log.Fatalf("startServer failed: %v", e)
                }
                addr = l.Addr().String()
-               go runStreamSyslog(l, done, wg)
+               sock = l
+               wg.Add(1)
+               go func() {
+                       defer wg.Done()
+                       runStreamSyslog(l, done, wg)
+               }()
        }
        return
 }
@@ -117,7 +122,7 @@ func TestWithSimulated(t *testing.T) {
 
        for _, tr := range transport {
                done := make(chan string)
-               addr, _ := startServer(tr, "", done)
+               addr, _, _ := startServer(tr, "", done)
                if tr == "unix" || tr == "unixgram" {
                        defer os.Remove(addr)
                }
@@ -137,8 +142,9 @@ func TestWithSimulated(t *testing.T) {
 func TestFlap(t *testing.T) {
        net := "unix"
        done := make(chan string)
-       addr, _ := startServer(net, "", done)
+       addr, sock, _ := startServer(net, "", done)
        defer os.Remove(addr)
+       defer sock.Close()
 
        s, err := Dial(net, addr, LOG_INFO|LOG_USER, "syslog_test")
        if err != nil {
@@ -152,7 +158,8 @@ func TestFlap(t *testing.T) {
        check(t, msg, <-done)
 
        // restart the server
-       startServer(net, addr, done)
+       _, sock2, _ := startServer(net, addr, done)
+       defer sock2.Close()
 
        // and try retransmitting
        msg = "Moo 3"
@@ -242,7 +249,8 @@ func TestWrite(t *testing.T) {
        } else {
                for _, test := range tests {
                        done := make(chan string)
-                       addr, _ := startServer("udp", "", done)
+                       addr, sock, _ := startServer("udp", "", done)
+                       defer sock.Close()
                        l, err := Dial("udp", addr, test.pri, test.pre)
                        if err != nil {
                                t.Fatalf("syslog.Dial() failed: %v", err)
@@ -263,7 +271,8 @@ func TestWrite(t *testing.T) {
 }
 
 func TestConcurrentWrite(t *testing.T) {
-       addr, _ := startServer("udp", "", make(chan string))
+       addr, sock, _ := startServer("udp", "", make(chan string))
+       defer sock.Close()
        w, err := Dial("udp", addr, LOG_USER|LOG_ERR, "how's it going?")
        if err != nil {
                t.Fatalf("syslog.Dial() failed: %v", err)
@@ -289,7 +298,7 @@ func TestConcurrentReconnect(t *testing.T) {
 
        net := "unix"
        done := make(chan string)
-       addr, srvWG := startServer(net, "", done)
+       addr, sock, srvWG := startServer(net, "", done)
        defer os.Remove(addr)
 
        // count all the messages arriving
@@ -327,6 +336,7 @@ func TestConcurrentReconnect(t *testing.T) {
                }()
        }
        wg.Wait()
+       sock.Close()
        srvWG.Wait()
        close(done)