8331932: Startup regressions in 23-b13

Reviewed-by: alanb, naoto, liach

src/java.base/share/classes/java/util/Locale.java

@@ -48,6 +48,7 @@ import java.io.Serializable;
 import java.text.DateFormat;
 import java.text.MessageFormat;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.Function;
 import java.util.spi.LocaleNameProvider;
 import java.util.stream.Stream;
 
@@ -980,29 +981,36 @@ public final class Locale implements Cloneable, Serializable {
         return getInstance(baseloc, extensions);
     }
 
+
     static Locale getInstance(BaseLocale baseloc, LocaleExtensions extensions) {
         if (extensions == null) {
             Locale locale = CONSTANT_LOCALES.get(baseloc);
             if (locale != null) {
                 return locale;
             }
-            return LOCALE_CACHE.computeIfAbsent(baseloc, Locale::createLocale);
+            return LOCALE_CACHE.computeIfAbsent(baseloc, LOCALE_CREATOR);
         } else {
             LocaleKey key = new LocaleKey(baseloc, extensions);
-            return LOCALE_CACHE.computeIfAbsent(key, Locale::createLocale);
+            return LOCALE_CACHE.computeIfAbsent(key, LOCALE_CREATOR);
         }
     }
 
-    private static final ReferencedKeyMap<Object, Locale> LOCALE_CACHE = ReferencedKeyMap.create(true, ConcurrentHashMap::new);
-    private static Locale createLocale(Object key) {
-        if (key instanceof BaseLocale base) {
-            return new Locale(base, null);
+    private static final ReferencedKeyMap<Object, Locale> LOCALE_CACHE
+            = ReferencedKeyMap.create(true, ReferencedKeyMap.concurrentHashMapSupplier());
+
+    private static final Function<Object, Locale> LOCALE_CREATOR = new Function<>() {
+        @Override
+        public Locale apply(Object key) {
+            if (key instanceof BaseLocale base) {
+                return new Locale(base, null);
+            }
+            LocaleKey lk = (LocaleKey)key;
+            return new Locale(lk.base, lk.exts);
         }
-        LocaleKey lk = (LocaleKey)key;
-        return new Locale(lk.base, lk.exts);
-    }
+    };
 
     private static final class LocaleKey {
+
         private final BaseLocale base;
         private final LocaleExtensions exts;
         private final int hash;

src/java.base/share/classes/jdk/internal/util/ReferencedKeyMap.java

@@ -99,6 +99,21 @@ public final class ReferencedKeyMap<K, V> implements Map<K, V> {
      */
     private final ReferenceQueue<K> stale;
 
+    /**
+     * @return a supplier to create a {@code ConcurrentHashMap} appropriate for use in the
+     *         create methods.
+     * @param <K> the type of keys maintained by the new map
+     * @param <V> the type of mapped values
+     */
+    public static <K, V> Supplier<Map<ReferenceKey<K>, V>> concurrentHashMapSupplier() {
+        return new Supplier<>() {
+            @Override
+            public Map<ReferenceKey<K>, V> get() {
+                return new ConcurrentHashMap<>();
+            }
+        };
+    }
+
     /**
      * Private constructor.
      *

src/java.base/share/classes/jdk/internal/util/ReferencedKeySet.java

@@ -75,6 +75,15 @@ public final class ReferencedKeySet<T> extends AbstractSet<T> {
      */
     final ReferencedKeyMap<T, ReferenceKey<T>> map;
 
+    /**
+     * @return a supplier to create a {@code ConcurrentHashMap} appropriate for use in the
+     *         create methods.
+     * @param <E> the type of elements maintained by this set
+     */
+    public static <E> Supplier<Map<ReferenceKey<E>, ReferenceKey<E>>> concurrentHashMapSupplier() {
+        return ReferencedKeyMap.concurrentHashMapSupplier();
+    }
+
     /**
      * Private constructor.
      *

src/java.base/share/classes/sun/util/locale/BaseLocale.java

@@ -38,7 +38,7 @@ import jdk.internal.util.StaticProperty;
 import jdk.internal.vm.annotation.Stable;
 
 import java.util.StringJoiner;
-import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.UnaryOperator;
 
 public final class BaseLocale {
 
@@ -93,7 +93,7 @@ public final class BaseLocale {
 
     // Interned BaseLocale cache
     private static final ReferencedKeySet<BaseLocale> CACHE =
-            ReferencedKeySet.create(true, ConcurrentHashMap::new);
+            ReferencedKeySet.create(true, ReferencedKeySet.concurrentHashMapSupplier());
 
     public static final String SEP = "_";
 
@@ -164,13 +164,21 @@ public final class BaseLocale {
         // "interned" instance can subsequently be used by the Locale
         // instance which guarantees the locale components are properly cased/interned.
         return CACHE.intern(new BaseLocale(language, script, region, variant),
-            (b) -> new BaseLocale(
-                LocaleUtils.toLowerString(b.language).intern(),
-                LocaleUtils.toTitleString(b.script).intern(),
-                LocaleUtils.toUpperString(b.region).intern(),
-                b.variant.intern()));
+                // Avoid lambdas since this may be on the bootstrap path in many locales
+                INTERNER);
     }
 
+    public static final UnaryOperator<BaseLocale> INTERNER = new UnaryOperator<>() {
+        @Override
+        public BaseLocale apply(BaseLocale b) {
+            return new BaseLocale(
+                    LocaleUtils.toLowerString(b.language).intern(),
+                    LocaleUtils.toTitleString(b.script).intern(),
+                    LocaleUtils.toUpperString(b.region).intern(),
+                    b.variant.intern());
+        }
+    };
+
     public static String convertOldISOCodes(String language) {
         return switch (language) {
             case "he", "iw" -> OLD_ISO_CODES ? "iw" : "he";