Gossip comm test fix

Was notified that TestReconnections fails on ppc build with high probability.
Fixed a timely assumption in TestReConnections in gossip/comm/comm_test.go
Also changed the file name convention of the private and public keys to
be randomly generated.

Signed-off-by: Yacov Manevich <yacovm@il.ibm.com>
Change-Id: I9143efa5b7082ea1023fb1331386d5dcd01f2601

gossip/comm/comm_impl.go

@@ -525,8 +525,9 @@ func createGRPCLayer(port int) (*grpc.Server, net.Listener, grpc.DialOption) {
 	var serverOpts []grpc.ServerOption
 	var dialOpts grpc.DialOption
 
-	keyFileName := fmt.Sprintf("key.%d.pem", time.Now().UnixNano())
-	certFileName := fmt.Sprintf("cert.%d.pem", time.Now().UnixNano())
+
+	keyFileName := fmt.Sprintf("key.%d.pem", rand.Int63())
+	certFileName := fmt.Sprintf("cert.%d.pem", rand.Int63())
 
 	defer os.Remove(keyFileName)
 	defer os.Remove(certFileName)

gossip/comm/comm_test.go

@@ -420,21 +420,19 @@ func TestReConnections(t *testing.T) {
 
 	// comm1 connects to comm2
 	comm1.Send(createGossipMsg(), remotePeer(3612))
-	time.Sleep(100 * time.Millisecond)
+	waitForMessages(t, out2 , 1, "Comm2 didn't receive a message from comm1 in a timely manner")
+	time.Sleep(time.Second)
 	// comm2 sends to comm1
 	comm2.Send(createGossipMsg(), remotePeer(3611))
-	time.Sleep(100 * time.Millisecond)
-
-	assert.Equal(t, 1, len(out2))
-	assert.Equal(t, 1, len(out1))
+	waitForMessages(t, out1 , 1, "Comm1 didn't receive a message from comm2 in a timely manner")
 
 	comm1.Stop()
 	comm1, _ = newCommInstance(3611, naiveSec)
+	time.Sleep(time.Second)
+	out1 = make(chan uint64, 1)
 	go reader(out1, comm1.Accept(acceptAll))
-	time.Sleep(300 * time.Millisecond)
 	comm2.Send(createGossipMsg(), remotePeer(3611))
-	time.Sleep(100 * time.Millisecond)
-	assert.Equal(t, 2, len(out1))
+	waitForMessages(t, out1 , 1, "Comm1 didn't receive a message from comm2 in a timely manner")
 }
 
 func TestProbe(t *testing.T) {
@@ -498,7 +496,7 @@ func remotePeer(port int) *RemotePeer {
 func waitForMessages(t *testing.T, msgChan chan uint64, count int, errMsg string) {
 	c := 0
 	waiting := true
-	ticker := time.NewTicker(time.Duration(5) * time.Second)
+	ticker := time.NewTicker(time.Duration(10) * time.Second)
 	for waiting {
 		select {
 		case <-msgChan: