From 6307344e3b129409ca7d2f0694224bc3d832fd44 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rub=C3=A9n=20Porras=20Campo?= <pcr@avaloq.com>
Date: Fri, 29 Nov 2024 16:22:21 +0100
Subject: [PATCH] use proper Double-checked locking

---
 .../xtext/layered/DefaultXtextTargetPlatform.java   | 13 ++++++++++---
 .../PatternAwareEObjectDescriptionLookUp.java       |  9 +++++----
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/com.avaloq.tools.ddk.xtext/src/com/avaloq/tools/ddk/xtext/layered/DefaultXtextTargetPlatform.java b/com.avaloq.tools.ddk.xtext/src/com/avaloq/tools/ddk/xtext/layered/DefaultXtextTargetPlatform.java
index 5122d2245..f63490367 100644
--- a/com.avaloq.tools.ddk.xtext/src/com/avaloq/tools/ddk/xtext/layered/DefaultXtextTargetPlatform.java
+++ b/com.avaloq.tools.ddk.xtext/src/com/avaloq/tools/ddk/xtext/layered/DefaultXtextTargetPlatform.java
@@ -32,10 +32,17 @@ public class DefaultXtextTargetPlatform implements IXtextTargetPlatform {
 
   @Override
   public IResourceDescriptionsData getIResourceDescriptionsData() {
-    if (index == null) {
-      index = new DelegatingResourceDescriptionsData(new ResourceDescriptionsData(Collections.emptyList()));
+    IResourceDescriptionsData localRef = index;
+    if (localRef == null) {
+      synchronized (this) {
+        localRef = index;
+        if (localRef == null) {
+          localRef = new DelegatingResourceDescriptionsData(new ResourceDescriptionsData(Collections.emptyList()));
+          index = localRef;
+        }
+      }
     }
-    return index;
+    return localRef;
   }
 
   @Override
diff --git a/com.avaloq.tools.ddk.xtext/src/com/avaloq/tools/ddk/xtext/resource/PatternAwareEObjectDescriptionLookUp.java b/com.avaloq.tools.ddk.xtext/src/com/avaloq/tools/ddk/xtext/resource/PatternAwareEObjectDescriptionLookUp.java
index d9f7979d6..8f269e754 100644
--- a/com.avaloq.tools.ddk.xtext/src/com/avaloq/tools/ddk/xtext/resource/PatternAwareEObjectDescriptionLookUp.java
+++ b/com.avaloq.tools.ddk.xtext/src/com/avaloq/tools/ddk/xtext/resource/PatternAwareEObjectDescriptionLookUp.java
@@ -86,13 +86,14 @@ protected Map<QualifiedName, List<IEObjectDescription>> getNameToObjects() {
   }
 
   protected QualifiedNameLookup<IEObjectDescription> getNameToObjectsLookup() {
-    if (nameToObjectsLookup == null) {
+    QualifiedNameLookup<IEObjectDescription> localMap = nameToObjectsLookup;
+    if (localMap == null) {
       synchronized (this) {
         // CHECKSTYLE:OFF with volatile it is ok
-        if (nameToObjectsLookup == null) {
+        if (localMap == null) {
           // CHECKSTYLE:ON with volatile it is ok
           Iterable<IEObjectDescription> allDescriptions = getExportedObjects();
-          QualifiedNameLookup<IEObjectDescription> localMap = QualifiedNameSegmentTreeLookup.createNameLookupCache("PatternAwareEObjectDescriptionLookUp#localMap", IEObjectDescription.class, false); //$NON-NLS-1$
+          localMap = QualifiedNameSegmentTreeLookup.createNameLookupCache("PatternAwareEObjectDescriptionLookUp#localMap", IEObjectDescription.class, false); //$NON-NLS-1$
           if (allDescriptions instanceof RandomAccess) {
             List<IEObjectDescription> asList = (List<IEObjectDescription>) allDescriptions;
             for (IEObjectDescription description : asList) {
@@ -107,7 +108,7 @@ protected QualifiedNameLookup<IEObjectDescription> getNameToObjectsLookup() {
         }
       }
     }
-    return this.nameToObjectsLookup;
+    return localMap;
   }
 
 }