8377712: ConstantPool of WeakReferenceKey is not deterministic in CDS archive

Reviewed-by: liach, kvn

src/hotspot/share/cds/aotMetaspace.cpp

@@ -1148,7 +1148,7 @@ void AOTMetaspace::dump_static_archive_impl(StaticArchiveBuilder& builder, TRAPS
     if (CDSConfig::is_dumping_full_module_graph()) {
       ClassLoaderDataShared::ensure_module_entry_tables_exist();
       ClassLoaderDataShared::build_tables(CHECK);
-      HeapShared::reset_archived_object_states(CHECK);
+      HeapShared::prepare_for_archiving(CHECK);
     }
 
     AOTReferenceObjSupport::initialize(CHECK);

src/hotspot/share/cds/heapShared.cpp

@@ -247,6 +247,28 @@ void HeapShared::reset_archived_object_states(TRAPS) {
   reset_states(boot_loader(), CHECK);
 }
 
+void HeapShared::ensure_determinism(TRAPS) {
+  TempNewSymbol class_name = SymbolTable::new_symbol("jdk/internal/util/WeakReferenceKey");
+  TempNewSymbol method_name = SymbolTable::new_symbol("ensureDeterministicAOTCache");
+
+  Klass* weak_ref_key_class = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
+  precond(weak_ref_key_class != nullptr);
+
+  log_debug(aot)("Calling WeakReferenceKey::ensureDeterministicAOTCache(Object.class)");
+  JavaValue result(T_BOOLEAN);
+  JavaCalls::call_static(&result,
+                         weak_ref_key_class,
+                         method_name,
+                         vmSymbols::void_boolean_signature(),
+                         CHECK);
+  assert(result.get_jboolean() == false, "sanity");
+}
+
+void HeapShared::prepare_for_archiving(TRAPS) {
+  reset_archived_object_states(CHECK);
+  ensure_determinism(CHECK);
+}
+
 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
 
 bool HeapShared::is_archived_heap_in_use() {

src/hotspot/share/cds/heapShared.hpp

@@ -382,8 +382,10 @@ private:
   static bool walk_one_object(PendingOopStack* stack, int level, KlassSubGraphInfo* subgraph_info,
                               oop orig_obj, oop referrer);
 
- public:
   static void reset_archived_object_states(TRAPS);
+  static void ensure_determinism(TRAPS);
+ public:
+  static void prepare_for_archiving(TRAPS);
   static void create_archived_object_cache() {
     _archived_object_cache =
       new (mtClass)ArchivedObjectCache(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);

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

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2023, 2026, 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
@@ -88,4 +88,18 @@ final class WeakReferenceKey<T> extends WeakReference<T> implements ReferenceKey
     public String toString() {
         return this.getClass().getCanonicalName() + "#" + System.identityHashCode(this);
     }
+
+    // WeakReferenceKey.equals() is usually executed in the AOT assembly phase. However,
+    // in some rare occasions, it's not executed (due to peculiarity of hash code and
+    // memory addressing??). As a result, the constant pool entries used by
+    // equals() are not resolved.
+    //
+    // The JVM calls ensureDeterministicAOTCache() during the AOT assembly phase to ensure
+    // that the constant pool entries used by equals() are resolved, so that the
+    // the JDK's default CDS archives have deterministic contents.
+    private static boolean ensureDeterministicAOTCache() {
+        WeakReferenceKey<String> k1 = new WeakReferenceKey<>("1", null);
+        WeakReferenceKey<String> k2 = new WeakReferenceKey<>("2", null);
+        return k1.equals(k2);
+    }
 }