proxy/userspace: use waitgroups instead of sketchy atomic ops in testcases

Instead of relying on atomic ops to increment/decrement at the right time
just use waitgroups to provide hard synchronization points.

pkg/proxy/userspace/proxier.go

@@ -68,6 +68,29 @@ type ServiceInfo struct {
 	stickyMaxAgeSeconds int
 	// Deprecated, but required for back-compat (including e2e)
 	externalIPs []string
+
+	// isStartedAtomic is set to non-zero when the service's socket begins
+	// accepting requests. Used in testcases. Only access this with atomic ops.
+	isStartedAtomic int32
+	// isFinishedAtomic is set to non-zero when the service's socket shuts
+	// down. Used in testcases. Only access this with atomic ops.
+	isFinishedAtomic int32
+}
+
+func (info *ServiceInfo) setStarted() {
+	atomic.StoreInt32(&info.isStartedAtomic, 1)
+}
+
+func (info *ServiceInfo) IsStarted() bool {
+	return atomic.LoadInt32(&info.isStartedAtomic) != 0
+}
+
+func (info *ServiceInfo) setFinished() {
+	atomic.StoreInt32(&info.isFinishedAtomic, 1)
+}
+
+func (info *ServiceInfo) IsFinished() bool {
+	return atomic.LoadInt32(&info.isFinishedAtomic) != 0
 }
 
 func (info *ServiceInfo) setAlive(b bool) {
@@ -124,7 +147,6 @@ type Proxier struct {
 	udpIdleTimeout  time.Duration
 	portMapMutex    sync.Mutex
 	portMap         map[portMapKey]*portMapValue
-	numProxyLoops   int32 // use atomic ops to access this; mostly for testing
 	listenIP        net.IP
 	iptables        iptables.Interface
 	hostIP          net.IP
@@ -427,14 +449,6 @@ func (proxier *Proxier) getServiceInfo(service proxy.ServicePortName) (*ServiceI
 	return info, ok
 }
 
-// addServiceOnPort lockes the proxy before calling addServiceOnPortInternal.
-// Used from testcases.
-func (proxier *Proxier) addServiceOnPort(service proxy.ServicePortName, protocol v1.Protocol, proxyPort int, timeout time.Duration) (*ServiceInfo, error) {
-	proxier.mu.Lock()
-	defer proxier.mu.Unlock()
-	return proxier.addServiceOnPortInternal(service, protocol, proxyPort, timeout)
-}
-
 // addServiceOnPortInternal starts listening for a new service, returning the ServiceInfo.
 // Pass proxyPort=0 to allocate a random port. The timeout only applies to UDP
 // connections, for now.
@@ -465,12 +479,10 @@ func (proxier *Proxier) addServiceOnPortInternal(service proxy.ServicePortName,
 	proxier.serviceMap[service] = si
 
 	klog.V(2).Infof("Proxying for service %q on %s port %d", service, protocol, portNum)
-	go func(service proxy.ServicePortName, proxier *Proxier) {
+	go func() {
 		defer runtime.HandleCrash()
-		atomic.AddInt32(&proxier.numProxyLoops, 1)
 		sock.ProxyLoop(service, si, proxier.loadBalancer)
-		atomic.AddInt32(&proxier.numProxyLoops, -1)
-	}(service, proxier)
+	}()
 
 	return si, nil
 }
@@ -509,6 +521,7 @@ func (proxier *Proxier) mergeService(service *v1.Service) sets.String {
 			if err := proxier.cleanupPortalAndProxy(serviceName, info); err != nil {
 				klog.Error(err)
 			}
+			info.setFinished()
 		}
 		proxyPort, err := proxier.proxyPorts.AllocateNext()
 		if err != nil {
@@ -541,6 +554,8 @@ func (proxier *Proxier) mergeService(service *v1.Service) sets.String {
 			klog.Errorf("Failed to open portal for %q: %v", serviceName, err)
 		}
 		proxier.loadBalancer.NewService(serviceName, info.sessionAffinityType, info.stickyMaxAgeSeconds)
+
+		info.setStarted()
 	}
 
 	return existingPorts
@@ -578,6 +593,7 @@ func (proxier *Proxier) unmergeService(service *v1.Service, existingPorts sets.S
 			klog.Error(err)
 		}
 		proxier.loadBalancer.DeleteService(serviceName)
+		info.setFinished()
 	}
 	for _, svcIP := range staleUDPServices.UnsortedList() {
 		if err := conntrack.ClearEntriesForIP(proxier.exec, svcIP, v1.ProtocolUDP); err != nil {