[slicer] SliceNode: attempts to fix possible concurrency problem getChildren()

GitOrigin-RevId: 36335a438817f42edcf59c87c6a4b2ce7520b4f9

platform/lang-impl/src/com/intellij/slicer/SliceNode.java

@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2016 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2023 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.slicer;
 
 import com.intellij.ide.projectView.PresentationData;
@@ -41,7 +27,7 @@ import java.util.Collections;
 import java.util.List;
 
 public class SliceNode extends AbstractTreeNode<SliceUsage> implements DuplicateNodeRenderer.DuplicatableNode<SliceNode>, MyColoredTreeCellRenderer {
-  protected List<SliceNode> myCachedChildren;
+  protected volatile List<SliceNode> myCachedChildren;
   boolean dupNodeCalculated;
   protected SliceNode duplicate;
   public final DuplicateMap targetEqualUsages;
@@ -81,7 +67,11 @@ public class SliceNode extends AbstractTreeNode<SliceUsage> implements Duplicate
       }
 
       synchronized (nodes) {
-        myCachedChildren = nodes;
+        if (myCachedChildren != null) {
+          nodes = myCachedChildren;
+        } else {
+          myCachedChildren = nodes;
+        }
       }
       return nodes;
     }