Merge pull request #478 from davoustp/contention-in-singleton-injecti…

…on-2.6.x [WW-5121] Fix: remove contention during Scope.SINGLETON injection
apache · Mar 23, 2021 · 49a4d6d · 49a4d6d
2 parents ca99c7b + cb2c67e
commit 49a4d6d
Showing 1 changed file with 7 additions and 5 deletions.
diff --git a/core/src/main/java/com/opensymphony/xwork2/inject/Scope.java b/core/src/main/java/com/opensymphony/xwork2/inject/Scope.java
@@ -44,15 +44,17 @@ <T> InternalFactory<? extends T> scopeFactory(Class<T> type, String name,
         @Override
         <T> InternalFactory<? extends T> scopeFactory(Class<T> type, String name, final InternalFactory<? extends T> factory) {
             return new InternalFactory<T>() {
-                T instance;
+                volatile T instance;
 
                 public T create(InternalContext context) {
-                    synchronized (context.getContainer()) {
-                        if (instance == null) {
-                            instance = InitializableFactory.wrapIfNeeded(factory).create(context);
+                    if (instance == null) {
+                        synchronized (context.getContainer()) {
+                            if (instance == null) {
+                                instance = InitializableFactory.wrapIfNeeded(factory).create(context);
+                            }
                         }
-                        return instance;
                     }
+                    return instance;
                 }
 
                 @Override