8351319: AOT cache support for custom class loaders broken since JDK-8348426

Reviewed-by: ccheung, matsaave, jrose

Author: iklam

src/hotspot/share/cds/aotArtifactFinder.cpp

@@ -152,10 +152,11 @@ void AOTArtifactFinder::find_artifacts() {
   SystemDictionaryShared::dumptime_table()->iterate_all_live_classes([&] (InstanceKlass* k, DumpTimeClassInfo& info) {
     if (!info.is_excluded() && _seen_classes->get(k) == nullptr) {
       info.set_excluded();
-      if (log_is_enabled(Info, cds)) {
+      info.set_has_checked_exclusion();
+      if (log_is_enabled(Debug, cds)) {
         ResourceMark rm;
-        log_info(cds)("Skipping %s: %s class", k->name()->as_C_string(),
-                      k->is_hidden() ? "Hidden" : "AOT tooling");
+        log_debug(cds)("Skipping %s: %s class", k->name()->as_C_string(),
+                      k->is_hidden() ? "Unreferenced hidden" : "AOT tooling");
       }
     }
   });
@@ -211,6 +212,10 @@ void AOTArtifactFinder::add_cached_instance_class(InstanceKlass* ik) {
   _seen_classes->put_if_absent(ik, &created);
   if (created) {
     _all_cached_classes->append(ik);
+    if (CDSConfig::is_dumping_final_static_archive() && ik->is_shared_unregistered_class()) {
+      // The following are not appliable to unregistered classes
+      return;
+    }
     scan_oops_in_instance_class(ik);
     if (ik->is_hidden() && CDSConfig::is_initing_classes_at_dump_time()) {
       bool succeed = AOTClassLinker::try_add_candidate(ik);

src/hotspot/share/cds/dumpTimeClassInfo.inline.hpp

@@ -1,6 +1,6 @@
 
 /*
- * Copyright (c) 2021, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 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
@@ -28,6 +28,7 @@
 
 #include "cds/dumpTimeClassInfo.hpp"
 
+#include "cds/cdsConfig.hpp"
 #include "classfile/systemDictionaryShared.hpp"
 #include "classfile/classLoaderData.inline.hpp"
 #include "oops/instanceKlass.hpp"
@@ -44,7 +45,10 @@ void DumpTimeSharedClassTable::iterate_all_live_classes(Function function) const
   auto wrapper = [&] (InstanceKlass* k, DumpTimeClassInfo& info) {
     assert(SafepointSynchronize::is_at_safepoint(), "invariant");
     assert_lock_strong(DumpTimeTable_lock);
-    if (k->is_loader_alive()) {
+    if (CDSConfig::is_dumping_final_static_archive() && !k->is_loaded()) {
+      assert(k->is_shared_unregistered_class(), "must be");
+      function(k, info);
+    } else if (k->is_loader_alive()) {
       function(k, info);
       assert(k->is_loader_alive(), "must not change");
     } else {

src/hotspot/share/cds/finalImageRecipes.cpp

@@ -102,7 +102,11 @@ void FinalImageRecipes::load_all_classes(TRAPS) {
     Klass* k = _all_klasses->at(i);
     if (k->is_instance_klass()) {
       InstanceKlass* ik = InstanceKlass::cast(k);
-      if (!ik->is_shared_unregistered_class() && !ik->is_hidden()) {
+      if (ik->is_shared_unregistered_class()) {
+        SystemDictionaryShared::init_dumptime_info(ik);
+        SystemDictionaryShared::add_unregistered_class(THREAD, ik);
+        SystemDictionaryShared::copy_unregistered_class_size_and_crc32(ik);
+      } else if (!ik->is_hidden()) {
         Klass* actual = SystemDictionary::resolve_or_fail(ik->name(), class_loader, true, CHECK);
         if (actual != ik) {
           ResourceMark rm(THREAD);

src/hotspot/share/classfile/systemDictionaryShared.cpp

@@ -465,6 +465,21 @@ bool SystemDictionaryShared::add_unregistered_class(Thread* current, InstanceKla
   return (klass == *v);
 }
 
+void SystemDictionaryShared::copy_unregistered_class_size_and_crc32(InstanceKlass* klass) {
+  precond(CDSConfig::is_dumping_final_static_archive());
+  precond(klass->is_shared());
+
+  // A shared class must have a RunTimeClassInfo record
+  const RunTimeClassInfo* record = find_record(&_static_archive._unregistered_dictionary,
+                                               nullptr, klass->name());
+  precond(record != nullptr);
+  precond(record->klass() == klass);
+
+  DumpTimeClassInfo* info = get_info(klass);
+  info->_clsfile_size = record->crc()->_clsfile_size;
+  info->_clsfile_crc32 = record->crc()->_clsfile_crc32;
+}
+
 void SystemDictionaryShared::set_shared_class_misc_info(InstanceKlass* k, ClassFileStream* cfs) {
   assert(CDSConfig::is_dumping_archive(), "sanity");
   assert(!is_builtin(k), "must be unregistered class");
@@ -667,7 +682,7 @@ bool SystemDictionaryShared::should_be_excluded(Klass* k) {
 }
 
 void SystemDictionaryShared::finish_exclusion_checks() {
-  if (CDSConfig::is_dumping_dynamic_archive()) {
+  if (CDSConfig::is_dumping_dynamic_archive() || CDSConfig::is_dumping_preimage_static_archive()) {
     // Do this first -- if a base class is excluded due to duplication,
     // all of its subclasses will also be excluded.
     ResourceMark rm;

src/hotspot/share/classfile/systemDictionaryShared.hpp

@@ -248,6 +248,7 @@ class SystemDictionaryShared: public SystemDictionary {
     return (k->shared_classpath_index() != UNREGISTERED_INDEX);
   }
   static bool add_unregistered_class(Thread* current, InstanceKlass* k);
+  static void copy_unregistered_class_size_and_crc32(InstanceKlass* klass);
 
   static void finish_exclusion_checks();
   static DumpTimeSharedClassTable* dumptime_table() { return _dumptime_table; }

src/hotspot/share/oops/constantPool.cpp

@@ -476,9 +476,23 @@ void ConstantPool::remove_unshareable_info() {
     return;
   }
 
+  bool update_resolved_reference = true;
+  if (CDSConfig::is_dumping_final_static_archive()) {
+    ConstantPool* src_cp = ArchiveBuilder::current()->get_source_addr(this);
+    InstanceKlass* src_holder = src_cp->pool_holder();
+    if (src_holder->is_shared_unregistered_class()) {
+      // Unregistered classes are not loaded in the AOT assembly phase. The resolved reference length
+      // is already saved during the training run.
+      precond(!src_holder->is_loaded());
+      precond(resolved_reference_length() >= 0);
+      precond(resolved_references() == nullptr);
+      update_resolved_reference = false;
+    }
+  }
+
   // resolved_references(): remember its length. If it cannot be restored
   // from the archived heap objects at run time, we need to dynamically allocate it.
-  if (cache() != nullptr) {
+  if (update_resolved_reference && cache() != nullptr) {
     set_resolved_reference_length(
         resolved_references() != nullptr ? resolved_references()->length() : 0);
     set_resolved_references(OopHandle());

src/hotspot/share/oops/klass.cpp

@@ -828,9 +828,15 @@ void Klass::remove_java_mirror() {
   if (CDSConfig::is_dumping_heap()) {
     Klass* src_k = ArchiveBuilder::current()->get_source_addr(this);
     oop orig_mirror = src_k->java_mirror();
-    oop scratch_mirror = HeapShared::scratch_java_mirror(orig_mirror);
-    if (scratch_mirror != nullptr) {
-      _archived_mirror_index = HeapShared::append_root(scratch_mirror);
+    if (orig_mirror == nullptr) {
+      assert(CDSConfig::is_dumping_final_static_archive(), "sanity");
+      assert(is_instance_klass(), "sanity");
+      assert(InstanceKlass::cast(this)->is_shared_unregistered_class(), "sanity");
+    } else {
+      oop scratch_mirror = HeapShared::scratch_java_mirror(orig_mirror);
+      if (scratch_mirror != nullptr) {
+        _archived_mirror_index = HeapShared::append_root(scratch_mirror);
+      }
     }
   }
 #endif

test/hotspot/jtreg/runtime/cds/appcds/aotClassLinking/BulkLoaderTest.java

@@ -31,11 +31,14 @@
  * @requires vm.cds.supports.aot.class.linking
  * @comment work around JDK-8345635
  * @requires !vm.jvmci.enabled
- * @library /test/jdk/lib/testlibrary /test/lib
+ * @library /test/jdk/lib/testlibrary /test/lib /test/hotspot/jtreg/runtime/cds/appcds/test-classes
  * @build InitiatingLoaderTester BadOldClassA BadOldClassB
- * @build BulkLoaderTest
+ * @build jdk.test.whitebox.WhiteBox BulkLoaderTest SimpleCusty
  * @run driver jdk.test.lib.helpers.ClassFileInstaller -jar BulkLoaderTestApp.jar BulkLoaderTestApp MyUtil InitiatingLoaderTester
  *                 BadOldClassA BadOldClassB
+ * @run driver jdk.test.lib.helpers.ClassFileInstaller -jar cust.jar
+ *                 SimpleCusty
+ * @run driver jdk.test.lib.helpers.ClassFileInstaller -jar WhiteBox.jar jdk.test.whitebox.WhiteBox
  * @run driver BulkLoaderTest STATIC
  */
 
@@ -44,30 +47,37 @@
  * @requires vm.cds.supports.aot.class.linking
  * @comment work around JDK-8345635
  * @requires !vm.jvmci.enabled
- * @library /test/jdk/lib/testlibrary /test/lib
+ * @library /test/jdk/lib/testlibrary /test/lib /test/hotspot/jtreg/runtime/cds/appcds/test-classes
  * @build InitiatingLoaderTester BadOldClassA BadOldClassB
- * @build jdk.test.whitebox.WhiteBox BulkLoaderTest
+ * @build jdk.test.whitebox.WhiteBox BulkLoaderTest SimpleCusty
  * @run driver jdk.test.lib.helpers.ClassFileInstaller -jar BulkLoaderTestApp.jar BulkLoaderTestApp MyUtil InitiatingLoaderTester
  *                 BadOldClassA BadOldClassB
- * @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
- * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:. BulkLoaderTest DYNAMIC
+ * @run driver jdk.test.lib.helpers.ClassFileInstaller -jar cust.jar
+ *                 SimpleCusty
+ * @run driver jdk.test.lib.helpers.ClassFileInstaller -jar WhiteBox.jar jdk.test.whitebox.WhiteBox
+ * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:WhiteBox.jar BulkLoaderTest DYNAMIC
  */
 
 /*
  * @test id=aot
  * @requires vm.cds.supports.aot.class.linking
  * @comment work around JDK-8345635
  * @requires !vm.jvmci.enabled
- * @library /test/jdk/lib/testlibrary /test/lib
- * @build InitiatingLoaderTester BadOldClassA BadOldClassB
- * @build BulkLoaderTest
+ * @library /test/jdk/lib/testlibrary /test/lib /test/hotspot/jtreg/runtime/cds/appcds/test-classes
+ * @build jdk.test.whitebox.WhiteBox InitiatingLoaderTester BadOldClassA BadOldClassB
+ * @build BulkLoaderTest SimpleCusty
  * @run driver jdk.test.lib.helpers.ClassFileInstaller -jar BulkLoaderTestApp.jar BulkLoaderTestApp MyUtil InitiatingLoaderTester
  *                 BadOldClassA BadOldClassB
+ * @run driver jdk.test.lib.helpers.ClassFileInstaller -jar WhiteBox.jar jdk.test.whitebox.WhiteBox
+ * @run driver jdk.test.lib.helpers.ClassFileInstaller -jar cust.jar
+ *                 SimpleCusty
  * @run driver BulkLoaderTest AOT
  */
 
 import java.io.File;
 import java.lang.StackWalker.StackFrame;
+import java.net.URL;
+import java.net.URLClassLoader;
 import java.util.List;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -76,6 +86,7 @@
 import jdk.test.lib.cds.CDSAppTester;
 import jdk.test.lib.helpers.ClassFileInstaller;
 import jdk.test.lib.process.OutputAnalyzer;
+import jdk.test.whitebox.WhiteBox;
 
 public class BulkLoaderTest {
     static final String appJar = ClassFileInstaller.getJarPath("BulkLoaderTestApp.jar");
@@ -114,6 +125,7 @@ public static void main(String[] args) throws Exception {
     static class Tester extends CDSAppTester {
         public Tester() {
             super(mainClass);
+            useWhiteBox(ClassFileInstaller.getJarPath("WhiteBox.jar"));
         }
 
         @Override
@@ -124,7 +136,7 @@ public String classpath(RunMode runMode) {
         @Override
         public String[] vmArgs(RunMode runMode) {
             return new String[] {
-                "-Xlog:cds,cds+aot+load",
+                "-Xlog:cds,cds+aot+load,cds+class=debug",
                 "-XX:+AOTClassLinking",
             };
         }
@@ -140,6 +152,12 @@ public String[] appCommandLine(RunMode runMode) {
         public void checkExecution(OutputAnalyzer out, RunMode runMode) throws Exception {
             if (isAOTWorkflow() && runMode == RunMode.TRAINING) {
                 out.shouldContain("Skipping BadOldClassA: Unlinked class not supported by AOTConfiguration");
+                out.shouldContain("Skipping SimpleCusty: Duplicated unregistered class");
+            }
+
+            if (isDumping(runMode)) {
+                // Check that we are archiving classes for custom class loaders.
+                out.shouldMatch("cds,class.* SimpleCusty");
             }
         }
     }
@@ -152,6 +170,7 @@ public static void main(String args[]) throws Exception {
         checkClasses();
         checkInitiatingLoader();
         checkOldClasses();
+        checkCustomLoader();
     }
 
     // Check the ClassLoader/Module/Package/ProtectionDomain/CodeSource of classes that are aot-linked
@@ -275,6 +294,38 @@ static void checkOldClasses() throws Exception {
             System.out.println("Caught VerifyError for BadOldClassB: " + e);
         }
     }
+
+
+    static void checkCustomLoader() throws Exception {
+        WhiteBox wb = WhiteBox.getWhiteBox();
+        for (int i = 0; i < 2; i++) {
+            Object o = initFromCustomLoader();
+            System.out.println(o);
+            Class c = o.getClass();
+            if (wb.isSharedClass(BulkLoaderTestApp.class)) {
+                // We are running with BulkLoaderTestApp from the AOT cache (or CDS achive)
+                if (i == 0) {
+                    if (!wb.isSharedClass(c)) {
+                        throw new RuntimeException("The first loader should load SimpleCusty from AOT cache (or CDS achive)");
+                    }
+                } else {
+                    if (wb.isSharedClass(c)) {
+                        throw new RuntimeException("The second loader should not load SimpleCusty from AOT cache (or CDS achive)");
+                    }
+                }
+            }
+        }
+    }
+
+    static Object initFromCustomLoader() throws Exception {
+        String path = "cust.jar";
+        URL url = new File(path).toURI().toURL();
+        URL[] urls = new URL[] {url};
+        URLClassLoader urlClassLoader =
+            new URLClassLoader("MyLoader", urls, null);
+        Class c = Class.forName("SimpleCusty", true, urlClassLoader);
+        return c.newInstance();
+    }
 }
 
 class MyUtil {

test/hotspot/jtreg/runtime/cds/appcds/dynamicArchive/LambdaCustomLoader.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, 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
@@ -51,7 +51,7 @@ static void test() throws Exception {
             "-Xlog:class+load,cds=debug,cds+dynamic",
             "-cp", appJar, mainClass, appJar, "init", "keep-alive")
             .assertNormalExit(output -> {
-                output.shouldMatch("Skipping.LambHello[$][$]Lambda.*0x.*:.Hidden.class")
+                output.shouldMatch("Skipping.LambHello[$][$]Lambda.*0x.*:.Unreferenced.hidden.class")
                       .shouldHaveExitValue(0);
             });
 

test/hotspot/jtreg/runtime/cds/appcds/dynamicArchive/LambdaProxyCallerIsHidden.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, 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
@@ -59,8 +59,8 @@ static void test() throws Exception {
             "-Xlog:class+load,cds+dynamic,cds=debug",
             "-cp", appJar, mainClass)
             .assertNormalExit(output -> {
-                output.shouldMatch("Skipping.LambdaHello_0x.*[$][$]Lambda.*:.Hidden.class")
-                      .shouldMatch("Skipping.LambdaHello.0x.*:.Hidden.class")
+                output.shouldMatch("Skipping.LambdaHello_0x.*[$][$]Lambda.*:.Unreferenced.hidden.class")
+                      .shouldMatch("Skipping.LambdaHello.0x.*:.Unreferenced.hidden.class")
                       .shouldHaveExitValue(0);
             });