WFLY-12022 Concurrent singleton service installation can cause servic…

…e to run simultaneously on 2 members.

clustering/server/src/main/java/org/wildfly/clustering/server/provider/CacheServiceProviderRegistry.java

@@ -81,7 +81,7 @@
  * all of which share the same {@link Cache} instance.
  * @author Paul Ferraro
  */
-@org.infinispan.notifications.Listener(sync = false)
+@org.infinispan.notifications.Listener
 public class CacheServiceProviderRegistry<T> implements ServiceProviderRegistry<T>, GroupListener, AutoCloseable {
 
     private static ThreadFactory createThreadFactory(Class<?> targetClass) {

clustering/server/src/main/java/org/wildfly/clustering/server/singleton/AbstractDistributedSingletonService.java

@@ -98,7 +98,7 @@ public void stop(StopContext context) {
     }
 
     @Override
-    public void providersChanged(Set<Node> nodes) {
+    public synchronized void providersChanged(Set<Node> nodes) {
         Group group = this.registry.get().getGroup();
         List<Node> candidates = new ArrayList<>(group.getMembership().getMembers());
         candidates.retainAll(nodes);
@@ -159,15 +159,15 @@ public void providersChanged(Set<Node> nodes) {
     }
 
     @Override
-    public void start() {
+    public synchronized void start() {
         // If we were not already the primary node
         if (this.primary.compareAndSet(false, true)) {
             this.primaryLifecycle.start();
         }
     }
 
     @Override
-    public void stop() {
+    public synchronized void stop() {
         // If we were the previous the primary node
         if (this.primary.compareAndSet(true, false)) {
             this.primaryLifecycle.stop();