8261941: Use ClassLoader for unregistered classes during -Xshare:dump

Reviewed-by: iklam, minqi

src/hotspot/share/cds/classListParser.cpp

@@ -29,6 +29,7 @@
 #include "cds/classListParser.hpp"
 #include "cds/lambdaFormInvokers.hpp"
 #include "cds/metaspaceShared.hpp"
+#include "cds/unregisteredClasses.hpp"
 #include "classfile/classLoaderExt.hpp"
 #include "classfile/javaClasses.inline.hpp"
 #include "classfile/symbolTable.hpp"
@@ -120,6 +121,13 @@ int ClassListParser::parse(TRAPS) {
         return 0; // THROW
       }
 
+      ResourceMark rm(THREAD);
+      char* ex_msg = (char*)"";
+      oop message = java_lang_Throwable::message(PENDING_EXCEPTION);
+      if (message != NULL) {
+        ex_msg = java_lang_String::as_utf8_string(message);
+      }
+      log_warning(cds)("%s: %s", PENDING_EXCEPTION->klass()->external_name(), ex_msg);
       // We might have an invalid class name or an bad class. Warn about it
       // and keep going to the next line.
       CLEAR_PENDING_EXCEPTION;
@@ -458,24 +466,22 @@ InstanceKlass* ClassListParser::load_class_from_source(Symbol* class_name, TRAPS
     THROW_NULL(vmSymbols::java_lang_ClassNotFoundException());
   }
 
-  InstanceKlass* k = ClassLoaderExt::load_class(class_name, _source, CHECK_NULL);
+  InstanceKlass* k = UnregisteredClasses::load_class(class_name, _source, CHECK_NULL);
   if (k->local_interfaces()->length() != _interfaces->length()) {
     print_specified_interfaces();
     print_actual_interfaces(k);
     error("The number of interfaces (%d) specified in class list does not match the class file (%d)",
           _interfaces->length(), k->local_interfaces()->length());
   }
 
-  bool added = SystemDictionaryShared::add_unregistered_class_for_static_archive(THREAD, k);
+  assert(k->is_shared_unregistered_class(), "must be");
+
+  bool added = SystemDictionaryShared::add_unregistered_class(THREAD, k);
   if (!added) {
     // We allow only a single unregistered class for each unique name.
     error("Duplicated class %s", _class_name);
   }
 
-  // This tells JVM_FindLoadedClass to not find this class.
-  k->set_shared_classpath_index(UNREGISTERED_INDEX);
-  k->clear_shared_class_loader_type();
-
   return k;
 }
 

src/hotspot/share/cds/unregisteredClasses.cpp

@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2021, 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.
+ *
+ * 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.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "cds/unregisteredClasses.hpp"
+#include "classfile/classFileStream.hpp"
+#include "classfile/classLoader.inline.hpp"
+#include "classfile/classLoaderExt.hpp"
+#include "classfile/javaClasses.inline.hpp"
+#include "classfile/symbolTable.hpp"
+#include "classfile/systemDictionaryShared.hpp"
+#include "classfile/vmSymbols.hpp"
+#include "memory/oopFactory.hpp"
+#include "memory/resourceArea.hpp"
+#include "oops/instanceKlass.hpp"
+#include "runtime/handles.hpp"
+#include "runtime/javaCalls.hpp"
+#include "services/threadService.hpp"
+
+// Load the class of the given name from the location given by path. The path is specified by
+// the "source:" in the class list file (see classListParser.cpp), and can be a directory or
+// a JAR file.
+InstanceKlass* UnregisteredClasses::load_class(Symbol* name, const char* path, TRAPS) {
+  assert(name != NULL, "invariant");
+  assert(DumpSharedSpaces, "this function is only used with -Xshare:dump");
+
+  {
+    PerfClassTraceTime vmtimer(ClassLoader::perf_sys_class_lookup_time(),
+                               THREAD->get_thread_stat()->perf_timers_addr(),
+                               PerfClassTraceTime::CLASS_LOAD);
+  }
+
+  Symbol* path_symbol = SymbolTable::new_symbol(path);
+  Handle url_classloader = get_url_classloader(path_symbol, CHECK_NULL);
+  Handle ext_class_name = java_lang_String::externalize_classname(name, CHECK_NULL);
+
+  JavaValue result(T_OBJECT);
+  JavaCallArguments args(2);
+  args.set_receiver(url_classloader);
+  args.push_oop(ext_class_name);
+  args.push_int(JNI_FALSE);
+  JavaCalls::call_virtual(&result,
+                          vmClasses::URLClassLoader_klass(),
+                          vmSymbols::loadClass_name(),
+                          vmSymbols::string_boolean_class_signature(),
+                          &args,
+                          CHECK_NULL);
+  assert(result.get_type() == T_OBJECT, "just checking");
+  oop obj = result.get_oop();
+  return InstanceKlass::cast(java_lang_Class::as_Klass(obj));
+}
+
+class URLClassLoaderTable : public ResourceHashtable<
+  Symbol*, Handle,
+  137, // prime number
+  ResourceObj::C_HEAP> {};
+
+static URLClassLoaderTable* _url_classloader_table = NULL;
+
+Handle UnregisteredClasses::create_url_classloader(Symbol* path, TRAPS) {
+  ResourceMark rm(THREAD);
+  JavaValue result(T_OBJECT);
+  Handle path_string = java_lang_String::create_from_str(path->as_C_string(), CHECK_NH);
+  JavaCalls::call_static(&result,
+                         vmClasses::jdk_internal_loader_ClassLoaders_klass(),
+                         vmSymbols::toFileURL_name(),
+                         vmSymbols::toFileURL_signature(),
+                         path_string, CHECK_NH);
+  assert(result.get_type() == T_OBJECT, "just checking");
+  oop url_h = result.get_oop();
+  objArrayHandle urls = oopFactory::new_objArray_handle(vmClasses::URL_klass(), 1, CHECK_NH);
+  urls->obj_at_put(0, url_h);
+
+  Handle url_classloader = JavaCalls::construct_new_instance(
+                             vmClasses::URLClassLoader_klass(),
+                             vmSymbols::url_array_classloader_void_signature(),
+                             urls, Handle(), CHECK_NH);
+  return url_classloader;
+}
+
+Handle UnregisteredClasses::get_url_classloader(Symbol* path, TRAPS) {
+  if (_url_classloader_table == NULL) {
+    _url_classloader_table = new (ResourceObj::C_HEAP, mtClass)URLClassLoaderTable();
+  }
+  Handle* url_classloader_ptr = _url_classloader_table->get(path);
+  if (url_classloader_ptr != NULL) {
+    return *url_classloader_ptr;
+  } else {
+    Handle url_classloader = create_url_classloader(path, CHECK_NH);
+    _url_classloader_table->put(path, url_classloader);
+    path->increment_refcount();
+    return url_classloader;
+  }
+}

src/hotspot/share/cds/unregisteredClasses.hpp

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2021, 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.
+ *
+ * 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.
+ *
+ */
+
+#ifndef SHARE_CDS_UNREGISTEREDCLASSES_HPP
+#define SHARE_CDS_UNREGISTEREDCLASSES_HPP
+
+#include "runtime/handles.hpp"
+
+class UnregisteredClasses: AllStatic {
+public:
+  static InstanceKlass* load_class(Symbol* h_name, const char* path, TRAPS);
+
+private:
+  static Handle create_url_classloader(Symbol* path, TRAPS);
+  static Handle get_url_classloader(Symbol* path, TRAPS);
+};
+
+#endif // SHARE_CDS_UNREGISTEREDCLASSES_HPP

src/hotspot/share/classfile/classLoaderExt.cpp

@@ -25,15 +25,13 @@
 #include "precompiled.hpp"
 #include "cds/filemap.hpp"
 #include "classfile/classFileParser.hpp"
-#include "classfile/classFileStream.hpp"
 #include "classfile/classLoader.inline.hpp"
 #include "classfile/classLoaderExt.hpp"
 #include "classfile/classLoaderData.inline.hpp"
 #include "classfile/classLoadInfo.hpp"
 #include "classfile/klassFactory.hpp"
 #include "classfile/modules.hpp"
 #include "classfile/systemDictionary.hpp"
-#include "classfile/systemDictionaryShared.hpp"
 #include "classfile/vmSymbols.hpp"
 #include "gc/shared/collectedHeap.hpp"
 #include "logging/log.hpp"
@@ -46,9 +44,7 @@
 #include "runtime/arguments.hpp"
 #include "runtime/handles.inline.hpp"
 #include "runtime/java.hpp"
-#include "runtime/javaCalls.hpp"
 #include "runtime/os.hpp"
-#include "services/threadService.hpp"
 #include "utilities/stringUtils.hpp"
 
 jshort ClassLoaderExt::_app_class_paths_start_index = ClassLoaderExt::max_classpath_index;
@@ -250,90 +246,3 @@ void ClassLoaderExt::record_result(const s2 classpath_index, InstanceKlass* resu
   result->set_shared_classpath_index(classpath_index);
   result->set_shared_class_loader_type(classloader_type);
 }
-
-// Load the class of the given name from the location given by path. The path is specified by
-// the "source:" in the class list file (see classListParser.cpp), and can be a directory or
-// a JAR file.
-InstanceKlass* ClassLoaderExt::load_class(Symbol* name, const char* path, TRAPS) {
-  assert(name != NULL, "invariant");
-  assert(DumpSharedSpaces, "this function is only used with -Xshare:dump");
-  ResourceMark rm(THREAD);
-  const char* class_name = name->as_C_string();
-  const char* file_name = file_name_for_class_name(class_name,
-                                                   name->utf8_length());
-  assert(file_name != NULL, "invariant");
-
-  // Lookup stream for parsing .class file
-  ClassFileStream* stream = NULL;
-  ClassPathEntry* e = find_classpath_entry_from_cache(THREAD, path);
-  if (e == NULL) {
-    THROW_NULL(vmSymbols::java_lang_ClassNotFoundException());
-  }
-
-  {
-    PerfClassTraceTime vmtimer(perf_sys_class_lookup_time(),
-                               THREAD->get_thread_stat()->perf_timers_addr(),
-                               PerfClassTraceTime::CLASS_LOAD);
-    stream = e->open_stream(THREAD, file_name);
-  }
-
-  if (stream == NULL) {
-    // open_stream could return NULL even when no exception has be thrown (JDK-8263632).
-    THROW_NULL(vmSymbols::java_lang_ClassNotFoundException());
-    return NULL;
-  }
-  stream->set_verify(true);
-
-  ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();
-  Handle protection_domain;
-  ClassLoadInfo cl_info(protection_domain);
-  InstanceKlass* k = KlassFactory::create_from_stream(stream,
-                                                      name,
-                                                      loader_data,
-                                                      cl_info,
-                                                      CHECK_NULL);
-  return k;
-}
-
-struct CachedClassPathEntry {
-  const char* _path;
-  ClassPathEntry* _entry;
-};
-
-static GrowableArray<CachedClassPathEntry>* cached_path_entries = NULL;
-
-ClassPathEntry* ClassLoaderExt::find_classpath_entry_from_cache(JavaThread* current, const char* path) {
-  // This is called from dump time so it's single threaded and there's no need for a lock.
-  assert(DumpSharedSpaces, "this function is only used with -Xshare:dump");
-  if (cached_path_entries == NULL) {
-    cached_path_entries = new (ResourceObj::C_HEAP, mtClass) GrowableArray<CachedClassPathEntry>(20, mtClass);
-  }
-  CachedClassPathEntry ccpe;
-  for (int i=0; i<cached_path_entries->length(); i++) {
-    ccpe = cached_path_entries->at(i);
-    if (strcmp(ccpe._path, path) == 0) {
-      if (i != 0) {
-        // Put recent entries at the beginning to speed up searches.
-        cached_path_entries->remove_at(i);
-        cached_path_entries->insert_before(0, ccpe);
-      }
-      return ccpe._entry;
-    }
-  }
-
-  struct stat st;
-  if (os::stat(path, &st) != 0) {
-    // File or directory not found
-    return NULL;
-  }
-  ClassPathEntry* new_entry = NULL;
-
-  new_entry = create_class_path_entry(current, path, &st, false, false);
-  if (new_entry == NULL) {
-    return NULL;
-  }
-  ccpe._path = strdup(path);
-  ccpe._entry = new_entry;
-  cached_path_entries->insert_before(0, ccpe);
-  return new_entry;
-}

src/hotspot/share/classfile/classLoaderExt.hpp

@@ -59,7 +59,6 @@ class ClassLoaderExt: public ClassLoader { // AllStatic
   static bool _has_non_jar_in_classpath;
 
   static char* read_manifest(JavaThread* current, ClassPathEntry* entry, jint *manifest_size, bool clean_text);
-  static ClassPathEntry* find_classpath_entry_from_cache(JavaThread* current, const char* path);
 
 public:
   static void process_jar_manifest(JavaThread* current, ClassPathEntry* entry, bool check_for_duplicates);
@@ -113,7 +112,6 @@ class ClassLoaderExt: public ClassLoader { // AllStatic
   }
 
   static void record_result(const s2 classpath_index, InstanceKlass* result);
-  static InstanceKlass* load_class(Symbol* h_name, const char* path, TRAPS);
   static void set_has_app_classes() {
     _has_app_classes = true;
   }

src/hotspot/share/classfile/systemDictionaryShared.cpp

@@ -430,6 +430,7 @@ class UnregisteredClassesTable : public ResourceHashtable<
 
 static UnregisteredClassesTable* _unregistered_classes_table = NULL;
 
+// true == class was successfully added; false == a duplicated class (with the same name) already exists.
 bool SystemDictionaryShared::add_unregistered_class(Thread* current, InstanceKlass* klass) {
   // We don't allow duplicated unregistered classes with the same name.
   // We only archive the first class with that name that succeeds putting
@@ -448,18 +449,6 @@ bool SystemDictionaryShared::add_unregistered_class(Thread* current, InstanceKla
   return (klass == *v);
 }
 
-// true == class was successfully added; false == a duplicated class (with the same name) already exists.
-bool SystemDictionaryShared::add_unregistered_class_for_static_archive(Thread* current, InstanceKlass* k) {
-  assert(DumpSharedSpaces, "only when dumping");
-  if (add_unregistered_class(current, k)) {
-    MutexLocker mu_r(current, Compile_lock); // add_to_hierarchy asserts this.
-    SystemDictionary::add_to_hierarchy(k);
-    return true;
-  } else {
-    return false;
-  }
-}
-
 // This function is called to lookup the super/interfaces of shared classes for
 // unregistered loaders. E.g., SharedClass in the below example
 // where "super:" (and optionally "interface:") have been specified.

src/hotspot/share/classfile/systemDictionaryShared.hpp

@@ -208,7 +208,6 @@ class SystemDictionaryShared: public SystemDictionary {
 
   static bool is_builtin_loader(ClassLoaderData* loader_data);
 
-  static bool add_unregistered_class_for_static_archive(Thread* current, InstanceKlass* k);
   static InstanceKlass* lookup_super_for_unregistered_class(Symbol* class_name,
                                                             Symbol* super_name,  bool is_superclass);
 

src/hotspot/share/classfile/vmClassMacros.hpp

@@ -135,6 +135,7 @@
   /* support for CDS */                                                                                         \
   do_klass(ByteArrayInputStream_klass,                  java_io_ByteArrayInputStream                          ) \
   do_klass(URL_klass,                                   java_net_URL                                          ) \
+  do_klass(URLClassLoader_klass,                        java_net_URLClassLoader                               ) \
   do_klass(Jar_Manifest_klass,                          java_util_jar_Manifest                                ) \
   do_klass(jdk_internal_loader_BuiltinClassLoader_klass,jdk_internal_loader_BuiltinClassLoader                ) \
   do_klass(jdk_internal_loader_ClassLoaders_klass,      jdk_internal_loader_ClassLoaders                      ) \