8151678: com/sun/jndi/ldap/LdapTimeoutTest.java failed due to timeout on DeadServerNoTimeoutTest is incorrect

Backport-of: 49a4d4b

Author: Alexey Bakhtin

src/java.naming/share/classes/com/sun/jndi/ldap/DefaultLdapDnsProvider.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -76,7 +76,7 @@ public Optional<LdapDnsProviderResult> lookupEndpoints(String url,
         }
 
         LdapDnsProviderResult res = new LdapDnsProviderResult(domainName, endpoints);
-        if (res.getEndpoints().size() == 0 && res.getDomainName().isEmpty()) {
+        if (res.getEndpoints().isEmpty() && res.getDomainName().isEmpty()) {
             return Optional.empty();
         } else {
             return Optional.of(res);

src/java.naming/share/classes/com/sun/jndi/ldap/LdapDnsProviderService.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -37,6 +37,8 @@
  * The {@code LdapDnsProviderService} is responsible for creating and providing
  * access to the registered {@code LdapDnsProvider}s. The {@link ServiceLoader}
  * is used to find and register any implementations of {@link LdapDnsProvider}.
+ *
+ * <p> Instances of this class are safe for use by multiple threads.
  */
 final class LdapDnsProviderService {
 
@@ -68,19 +70,19 @@ private LdapDnsProviderService() {
     }
 
     /**
-     * Retrieve the singleton static instance of LdapDnsProviderService.
+     * Retrieves the singleton instance of LdapDnsProviderService.
      */
     static LdapDnsProviderService getInstance() {
         if (service != null) return service;
-        synchronized(LOCK) {
+        synchronized (LOCK) {
             if (service != null) return service;
             service = new LdapDnsProviderService();
         }
         return service;
     }
 
     /**
-     * Retrieve result from the first provider that successfully resolves
+     * Retrieves result from the first provider that successfully resolves
      * the endpoints. If no results are found when calling installed
      * subclasses of {@code LdapDnsProvider} then this method will fall back
      * to the {@code DefaultLdapDnsProvider}.
@@ -91,14 +93,15 @@ static LdapDnsProviderService getInstance() {
     LdapDnsProviderResult lookupEndpoints(String url, Hashtable<?,?> env)
         throws NamingException
     {
-        Iterator<LdapDnsProvider> iterator = providers.iterator();
-        Hashtable<?, ?> envCopy = new Hashtable<>(env);
         LdapDnsProviderResult result = null;
-
-        while (result == null && iterator.hasNext()) {
-            result = iterator.next().lookupEndpoints(url, envCopy)
-                    .filter(r -> r.getEndpoints().size() > 0)
-                    .orElse(null);
+        Hashtable<?, ?> envCopy = new Hashtable<>(env);
+        synchronized (LOCK) {
+            Iterator<LdapDnsProvider> iterator = providers.iterator();
+            while (result == null && iterator.hasNext()) {
+                result = iterator.next().lookupEndpoints(url, envCopy)
+                        .filter(r -> !r.getEndpoints().isEmpty())
+                        .orElse(null);
+            }
         }
 
         if (result == null) {

test/jdk/ProblemList.txt

@@ -944,8 +944,6 @@ sun/tools/jhsdb/HeapDumpTest.java                               8193639 solaris-
 
 com/sun/jndi/ldap/DeadSSLLdapTimeoutTest.java                   8169942 linux-i586,macosx-all,windows-x64
 
-com/sun/jndi/ldap/LdapTimeoutTest.java                          8151678 generic-all
-
 com/sun/jndi/dns/ConfigTests/PortUnreachable.java               7164518 macosx-all
 
 javax/rmi/ssl/SSLSocketParametersTest.sh                        8162906 generic-all