8329135: Store Universe::*exception_instance() in CDS archive

Reviewed-by: vlivanov, ccheung

Author: iklam

src/hotspot/share/cds/heapShared.cpp

@@ -430,6 +430,12 @@ void HeapShared::archive_strings() {
   StringTable::set_shared_strings_array_index(append_root(shared_strings_array));
 }
 
+int HeapShared::archive_exception_instance(oop exception) {
+  bool success = archive_reachable_objects_from(1, _default_subgraph_info, exception);
+  assert(success, "sanity");
+  return append_root(exception);
+}
+
 void HeapShared::mark_native_pointers(oop orig_obj) {
   if (java_lang_Class::is_instance(orig_obj)) {
     ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset());
@@ -589,6 +595,7 @@ void HeapShared::copy_special_objects() {
   init_seen_objects_table();
   archive_java_mirrors();
   archive_strings();
+  Universe::archive_exception_instances();
   delete_seen_objects_table();
 }
 
@@ -1387,11 +1394,15 @@ void HeapShared::check_default_subgraph_classes() {
           i, subgraph_k->external_name());
     }
 
-    guarantee(subgraph_k->name()->equals("java/lang/Class") ||
-              subgraph_k->name()->equals("java/lang/String") ||
-              subgraph_k->name()->equals("[Ljava/lang/Object;") ||
-              subgraph_k->name()->equals("[C") ||
-              subgraph_k->name()->equals("[B"),
+    Symbol* name = ArchiveBuilder::current()->get_source_addr(subgraph_k->name());
+    guarantee(name == vmSymbols::java_lang_Class() ||
+              name == vmSymbols::java_lang_String() ||
+              name == vmSymbols::java_lang_ArithmeticException() ||
+              name == vmSymbols::java_lang_NullPointerException() ||
+              name == vmSymbols::java_lang_VirtualMachineError() ||
+              name == vmSymbols::object_array_signature() ||
+              name == vmSymbols::byte_array_signature() ||
+              name == vmSymbols::char_array_signature(),
               "default subgraph can have only these objects");
   }
 }

src/hotspot/share/cds/heapShared.hpp

@@ -365,6 +365,7 @@ class HeapShared: AllStatic {
     return _archived_object_cache;
   }
 
+  static int archive_exception_instance(oop exception);
   static void archive_objects(ArchiveHeapInfo* heap_info);
   static void copy_objects();
   static void copy_special_objects();

src/hotspot/share/cds/metaspaceShared.cpp

@@ -1466,8 +1466,7 @@ void MetaspaceShared::initialize_shared_spaces() {
   // done after ReadClosure.
   static_mapinfo->patch_heap_embedded_pointers();
   ArchiveHeapLoader::finish_initialization();
-
-  CDS_JAVA_HEAP_ONLY(Universe::update_archived_basic_type_mirrors());
+  Universe::load_archived_object_instances();
 
   // Close the mapinfo file
   static_mapinfo->close();

src/hotspot/share/memory/universe.cpp

@@ -149,10 +149,6 @@ volatile jint Universe::_preallocated_out_of_memory_error_avail_count = 0;
 OopHandle Universe::_msg_metaspace;
 OopHandle Universe::_msg_class_metaspace;
 
-OopHandle Universe::_null_ptr_exception_instance;
-OopHandle Universe::_arithmetic_exception_instance;
-OopHandle Universe::_virtual_machine_error_instance;
-
 OopHandle Universe::_reference_pending_list;
 
 Array<Klass*>* Universe::_the_array_interfaces_array = nullptr;
@@ -186,6 +182,52 @@ OopStorage*     Universe::_vm_global = nullptr;
 
 CollectedHeap*  Universe::_collectedHeap = nullptr;
 
+// These are the exceptions that are always created and are guatanteed to exist.
+// If possible, they can be stored as CDS archived objects to speed up AOT code.
+class BuiltinException {
+  OopHandle _instance;
+  CDS_JAVA_HEAP_ONLY(int _archived_root_index;)
+
+public:
+  BuiltinException() : _instance() {
+    CDS_JAVA_HEAP_ONLY(_archived_root_index = 0);
+  }
+
+  void init_if_empty(Symbol* symbol, TRAPS) {
+    if (_instance.is_empty()) {
+      Klass* k = SystemDictionary::resolve_or_fail(symbol, true, CHECK);
+      oop obj = InstanceKlass::cast(k)->allocate_instance(CHECK);
+      _instance = OopHandle(Universe::vm_global(), obj);
+    }
+  }
+
+  oop instance() {
+    return _instance.resolve();
+  }
+
+#if INCLUDE_CDS_JAVA_HEAP
+  void store_in_cds() {
+    _archived_root_index = HeapShared::archive_exception_instance(instance());
+  }
+
+  void load_from_cds() {
+    if (_archived_root_index >= 0) {
+      oop obj = HeapShared::get_root(_archived_root_index);
+      assert(obj != nullptr, "must be");
+      _instance = OopHandle(Universe::vm_global(), obj);
+    }
+  }
+
+  void serialize(SerializeClosure *f) {
+    f->do_int(&_archived_root_index);
+  }
+#endif
+};
+
+static BuiltinException _null_ptr_exception;
+static BuiltinException _arithmetic_exception;
+static BuiltinException _virtual_machine_error;
+
 objArrayOop Universe::the_empty_class_array ()  {
   return (objArrayOop)_the_empty_class_array.resolve();
 }
@@ -199,9 +241,9 @@ void Universe::set_system_thread_group(oop group) { _system_thread_group = OopHa
 oop Universe::the_null_string()                   { return _the_null_string.resolve(); }
 oop Universe::the_min_jint_string()               { return _the_min_jint_string.resolve(); }
 
-oop Universe::null_ptr_exception_instance()       { return _null_ptr_exception_instance.resolve(); }
-oop Universe::arithmetic_exception_instance()     { return _arithmetic_exception_instance.resolve(); }
-oop Universe::virtual_machine_error_instance()    { return _virtual_machine_error_instance.resolve(); }
+oop Universe::null_ptr_exception_instance()       { return _null_ptr_exception.instance(); }
+oop Universe::arithmetic_exception_instance()     { return _arithmetic_exception.instance(); }
+oop Universe::virtual_machine_error_instance()    { return _virtual_machine_error.instance(); }
 
 oop Universe::the_null_sentinel()                 { return _the_null_sentinel.resolve(); }
 
@@ -254,7 +296,13 @@ void Universe::set_archived_basic_type_mirror_index(BasicType t, int index) {
   _archived_basic_type_mirror_indices[t] = index;
 }
 
-void Universe::update_archived_basic_type_mirrors() {
+void Universe::archive_exception_instances() {
+  _null_ptr_exception.store_in_cds();
+  _arithmetic_exception.store_in_cds();
+  _virtual_machine_error.store_in_cds();
+}
+
+void Universe::load_archived_object_instances() {
   if (ArchiveHeapLoader::is_in_use()) {
     for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
       int index = _archived_basic_type_mirror_indices[i];
@@ -264,6 +312,10 @@ void Universe::update_archived_basic_type_mirrors() {
         _basic_type_mirrors[i] = OopHandle(vm_global(), mirror_oop);
       }
     }
+
+    _null_ptr_exception.load_from_cds();
+    _arithmetic_exception.load_from_cds();
+    _virtual_machine_error.load_from_cds();
   }
 }
 #endif
@@ -275,8 +327,11 @@ void Universe::serialize(SerializeClosure* f) {
     f->do_int(&_archived_basic_type_mirror_indices[i]);
     // if f->reading(): We can't call HeapShared::get_root() yet, as the heap
     // contents may need to be relocated. _basic_type_mirrors[i] will be
-    // updated later in Universe::update_archived_basic_type_mirrors().
+    // updated later in Universe::load_archived_object_instances().
   }
+  _null_ptr_exception.serialize(f);
+  _arithmetic_exception.serialize(f);
+  _virtual_machine_error.serialize(f);
 #endif
 
   f->do_ptr(&_fillerArrayKlassObj);
@@ -1021,27 +1076,19 @@ bool universe_post_init() {
     Universe::_delayed_stack_overflow_error_message = OopHandle(Universe::vm_global(), instance);
   }
 
-  // Setup preallocated NullPointerException
-  // (this is currently used for a cheap & dirty solution in compiler exception handling)
-  Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_NullPointerException(), true, CHECK_false);
-  instance = InstanceKlass::cast(k)->allocate_instance(CHECK_false);
-  Universe::_null_ptr_exception_instance = OopHandle(Universe::vm_global(), instance);
-
-  // Setup preallocated ArithmeticException
-  // (this is currently used for a cheap & dirty solution in compiler exception handling)
-  k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_ArithmeticException(), true, CHECK_false);
-  instance = InstanceKlass::cast(k)->allocate_instance(CHECK_false);
-  Universe::_arithmetic_exception_instance = OopHandle(Universe::vm_global(), instance);
+  // Setup preallocated NullPointerException/ArithmeticException
+  // (used for a cheap & dirty solution in compiler exception handling)
+  _null_ptr_exception.init_if_empty(vmSymbols::java_lang_NullPointerException(), CHECK_false);
+  _arithmetic_exception.init_if_empty(vmSymbols::java_lang_ArithmeticException(), CHECK_false);
 
   // Virtual Machine Error for when we get into a situation we can't resolve
-  k = vmClasses::VirtualMachineError_klass();
+  Klass* k = vmClasses::VirtualMachineError_klass();
   bool linked = InstanceKlass::cast(k)->link_class_or_fail(CHECK_false);
   if (!linked) {
      tty->print_cr("Unable to link/verify VirtualMachineError class");
      return false; // initialization failed
   }
-  instance = InstanceKlass::cast(k)->allocate_instance(CHECK_false);
-  Universe::_virtual_machine_error_instance = OopHandle(Universe::vm_global(), instance);
+  _virtual_machine_error.init_if_empty(vmSymbols::java_lang_VirtualMachineError(), CHECK_false);
 
   Handle msg = java_lang_String::create_from_str("/ by zero", CHECK_false);
   java_lang_Throwable::set_message(Universe::arithmetic_exception_instance(), msg());

src/hotspot/share/memory/universe.hpp

@@ -106,10 +106,6 @@ class Universe: AllStatic {
   static OopHandle _msg_metaspace;
   static OopHandle _msg_class_metaspace;
 
-  static OopHandle    _null_ptr_exception_instance;   // preallocated exception object
-  static OopHandle    _arithmetic_exception_instance; // preallocated exception object
-  static OopHandle    _virtual_machine_error_instance; // preallocated exception object
-
   // References waiting to be transferred to the ReferenceHandler
   static OopHandle    _reference_pending_list;
 
@@ -211,9 +207,10 @@ class Universe: AllStatic {
 
   static oop java_mirror(BasicType t);
 
+  static void load_archived_object_instances() NOT_CDS_JAVA_HEAP_RETURN;
 #if INCLUDE_CDS_JAVA_HEAP
   static void set_archived_basic_type_mirror_index(BasicType t, int index);
-  static void update_archived_basic_type_mirrors();
+  static void archive_exception_instances();
 #endif
 
   static oop      main_thread_group();