Adapt JDK-8358426 for Web Image: Improve lazy computation in Locale

The cache fields were moved and now use StableValue.supplier

Author: patrick96

web-image/mx.web-image/suite.py

@@ -185,7 +185,11 @@
                 "java.compiler",
             ],
             "requiresConcealed": {
-                "java.base": ["sun.nio.ch", "sun.security.provider", "jdk.internal.reflect"],
+                "java.base": [
+                    "sun.nio.ch",
+                    "sun.security.provider",
+                    "jdk.internal.reflect",
+                ],
                 "jdk.internal.vm.ci": ["jdk.vm.ci.code.site", "jdk.vm.ci.code", "jdk.vm.ci.common", "jdk.vm.ci.meta"],
             },
             "javaCompliance": "21+",

web-image/src/com.oracle.svm.hosted.webimage/src/com/oracle/svm/hosted/webimage/ResetStableSupplierTransformer.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2025, 2025, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package com.oracle.svm.hosted.webimage;
+
+import java.lang.reflect.Method;
+import java.util.function.Supplier;
+
+import org.graalvm.nativeimage.hosted.FieldValueTransformer;
+
+import com.oracle.svm.util.ReflectionUtil;
+
+/**
+ * Field value transformer that creates a new StableSupplier with the same {@link Supplier} as the
+ * original that was not initialized yet.
+ * <p>
+ * This can be used to reset caches that are based on stable value suppliers.
+ * <p>
+ * Uses reflection because StableSupplier is from JDK25 and proguard does not yet support class
+ * files from that version.
+ */
+public final class ResetStableSupplierTransformer implements FieldValueTransformer {
+    @Override
+    public Object transform(Object receiver, Object originalValue) {
+        Class<?> stableSupplierClass = ReflectionUtil.lookupClass("jdk.internal.lang.stable.StableSupplier");
+        Method stableSupplierOf = ReflectionUtil.lookupMethod(stableSupplierClass, "of", Supplier.class);
+        Method stableSupplierOriginal = ReflectionUtil.lookupMethod(stableSupplierClass, "original");
+        Object originalSupplier = ReflectionUtil.invokeMethod(stableSupplierOriginal, originalValue);
+        return ReflectionUtil.invokeMethod(stableSupplierOf, null, originalSupplier);
+    }
+}

web-image/src/com.oracle.svm.hosted.webimage/src/com/oracle/svm/hosted/webimage/WebImageFeature.java

@@ -35,7 +35,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.function.Predicate;
-import java.util.function.Supplier;
 
 import org.graalvm.nativeimage.AnnotationAccess;
 import org.graalvm.nativeimage.ImageSingletons;
@@ -189,35 +188,12 @@ public void beforeAnalysis(BeforeAnalysisAccess access) {
          *
          * These caches can contribute ~1MB to the image size, clearing them avoids this overhead at
          * the cost of having to recreate the Locale and BaseLocale objects once when they're
-         * requested.
-         *
-         * On JDK21, ReferencedKeySet and ReferencedKeyMap don't exist. We have to go through
-         * reflection to access them because analysis tools like spotbugs still run on JDK21
+         * requested at run-time.
          */
-        Field baseLocaleCacheField = accessImpl.findField("sun.util.locale.BaseLocale$1InterningCache", "CACHE");
-        Field localeCacheField = accessImpl.findField("java.util.Locale$LocaleCache", "LOCALE_CACHE");
-
-        access.registerFieldValueTransformer(baseLocaleCacheField, (receiver, originalValue) -> {
-            /*
-             * Executes `ReferencedKeySet.create(true,
-             * ReferencedKeySet.concurrentHashMapSupplier())` with reflection.
-             */
-            Class<?> referencedKeySetClazz = ReflectionUtil.lookupClass("jdk.internal.util.ReferencedKeySet");
-            Method createMethod = ReflectionUtil.lookupMethod(referencedKeySetClazz, "create", boolean.class, Supplier.class);
-            Method concurrentHashMapSupplierMethod = ReflectionUtil.lookupMethod(referencedKeySetClazz, "concurrentHashMapSupplier");
-            return ReflectionUtil.invokeMethod(createMethod, null, true, ReflectionUtil.invokeMethod(concurrentHashMapSupplierMethod, null));
-        });
-
-        access.registerFieldValueTransformer(localeCacheField, (receiver, originalValue) -> {
-            /*
-             * Executes `ReferencedKeyMap.create(true,
-             * ReferencedKeyMap.concurrentHashMapSupplier())` with reflection.
-             */
-            Class<?> referencedKeyMapClazz = ReflectionUtil.lookupClass("jdk.internal.util.ReferencedKeyMap");
-            Method createMethod = ReflectionUtil.lookupMethod(referencedKeyMapClazz, "create", boolean.class, Supplier.class);
-            Method concurrentHashMapSupplierMethod = ReflectionUtil.lookupMethod(referencedKeyMapClazz, "concurrentHashMapSupplier");
-            return ReflectionUtil.invokeMethod(createMethod, null, true, ReflectionUtil.invokeMethod(concurrentHashMapSupplierMethod, null));
-        });
+        Field baseLocaleCacheField = accessImpl.findField("sun.util.locale.BaseLocale", "CACHE");
+        Field localeCacheField = accessImpl.findField("java.util.Locale", "LOCALE_CACHE");
+        access.registerFieldValueTransformer(baseLocaleCacheField, new ResetStableSupplierTransformer());
+        access.registerFieldValueTransformer(localeCacheField, new ResetStableSupplierTransformer());
     }
 
     @Override
@@ -341,4 +317,5 @@ private boolean neverInlineTrivial(@SuppressWarnings("unused") AnalysisMethod ca
          */
         return AnnotationAccess.isAnnotationPresent(callee, JS.class);
     }
+
 }