Make class initialization sealing/unsealing mechanism thread safe.

Author: cstancu

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/NativeImageGenerator.java

@@ -815,7 +815,7 @@ protected boolean runPointsToAnalysis(String imageName, OptionValues options, De
                 ServiceCatalogSupport.singleton().enableServiceCatalogMapTransformer(config);
                 featureHandler.forEachFeature(feature -> feature.beforeAnalysis(config));
                 ServiceCatalogSupport.singleton().seal();
-                bb.getHostVM().getClassInitializationSupport().setConfigurationSealed(true);
+                bb.getHostVM().getClassInitializationSupport().sealConfiguration();
                 if (ImageLayerBuildingSupport.buildingImageLayer()) {
                     ImageSingletons.lookup(LoadImageSingletonFeature.class).processRegisteredSingletons(aUniverse);
                 }

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/classinitialization/ClassInitializationSupport.java

@@ -125,7 +125,29 @@ public ClassInitializationSupport(MetaAccessProvider metaAccess, ImageClassLoade
         this.loader = loader;
     }
 
-    public void setConfigurationSealed(boolean sealed) {
+    /**
+     * Seal the configuration, blocking if another thread is trying to seal the configuration or an
+     * unsealed-configuration window is currently open in another thread.
+     */
+    public synchronized void sealConfiguration() {
+        setConfigurationSealed(true);
+    }
+
+    /**
+     * Run the action in an unsealed-configuration window, blocking if another thread is trying to
+     * seal the configuration or an unsealed-configuration window is currently open in another
+     * thread. The window is reentrant, i.e., it will not block the thread that opened the window
+     * from trying to reenter the window. Note that if the configuration was not sealed when the
+     * window was opened this will not affect the seal status.
+     */
+    public synchronized void withUnsealedConfiguration(Runnable action) {
+        var previouslySealed = configurationSealed;
+        setConfigurationSealed(false);
+        action.run();
+        setConfigurationSealed(previouslySealed);
+    }
+
+    private void setConfigurationSealed(boolean sealed) {
         configurationSealed = sealed;
         if (configurationSealed && ClassInitializationOptions.PrintClassInitialization.getValue()) {
             List<ClassOrPackageConfig> allConfigs = classInitializationConfiguration.allConfigs();

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/xml/XMLParsersRegistration.java

@@ -123,31 +123,30 @@ List<String> xmlParserClasses() {
     static class TransformerClassesAndResources extends XMLParsersRegistration {
 
         @Override
+        @SuppressWarnings("try")
         void registerResources() {
             /*
              * To allow register new resource bundle classes during analysis phase
              */
             ClassInitializationSupport classInitializationSupport = (ClassInitializationSupport) ImageSingletons.lookup(RuntimeClassInitializationSupport.class);
-            classInitializationSupport.setConfigurationSealed(false);
-
-            ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xml.internal.serializer.utils.SerializerMessages");
-            ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMessages");
-            ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xml.internal.serializer.Encodings");
-            ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xml.internal.serializer.HTMLEntities");
-            ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xml.internal.serializer.XMLEntities");
-            ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.xpath.regex.message");
-            ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.msg.DOMMessages");
-            ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.msg.DatatypeMessages");
-            ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.msg.JAXPValidationMessages");
-            ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.msg.SAXMessages");
-            ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.msg.XIncludeMessages");
-            ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.msg.XMLMessages");
-            ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.msg.XMLSchemaMessages");
-            ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.msg.XMLSerializerMessages");
-            ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.msg.XPointerMessages");
-            ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xalan.internal.res.XSLTInfo");
-
-            classInitializationSupport.setConfigurationSealed(true);
+            classInitializationSupport.withUnsealedConfiguration(() -> {
+                ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xml.internal.serializer.utils.SerializerMessages");
+                ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMessages");
+                ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xml.internal.serializer.Encodings");
+                ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xml.internal.serializer.HTMLEntities");
+                ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xml.internal.serializer.XMLEntities");
+                ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.xpath.regex.message");
+                ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.msg.DOMMessages");
+                ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.msg.DatatypeMessages");
+                ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.msg.JAXPValidationMessages");
+                ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.msg.SAXMessages");
+                ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.msg.XIncludeMessages");
+                ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.msg.XMLMessages");
+                ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.msg.XMLSchemaMessages");
+                ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.msg.XMLSerializerMessages");
+                ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xerces.internal.impl.msg.XPointerMessages");
+                ResourcesRegistry.singleton().addResourceBundles(ConfigurationCondition.alwaysTrue(), "com.sun.org.apache.xalan.internal.res.XSLTInfo");
+            });
         }
 
         @Override