8011803: release_C_heap_structures is never called for anonymous classes.

Summary: Call this function from the ClassLoaderData destructor instead of the system dictionary walk.
Reviewed-by: stefank, mgerdin

src/share/vm/classfile/classLoaderData.cpp

@@ -277,6 +277,9 @@ void ClassLoaderData::remove_class(Klass* scratch_class) {
 void ClassLoaderData::unload() {
   _unloading = true;
 
+  // Tell serviceability tools these classes are unloading
+  classes_do(InstanceKlass::notify_unload_class);
+
   if (TraceClassLoaderData) {
     ResourceMark rm;
     tty->print("[ClassLoaderData: unload loader data "PTR_FORMAT, this);
@@ -300,6 +303,9 @@ bool ClassLoaderData::is_alive(BoolObjectClosure* is_alive_closure) const {
 
 
 ClassLoaderData::~ClassLoaderData() {
+  // Release C heap structures for all the classes.
+  classes_do(InstanceKlass::release_C_heap_structures);
+
   Metaspace *m = _metaspace;
   if (m != NULL) {
     _metaspace = NULL;

src/share/vm/classfile/dictionary.cpp

@@ -27,7 +27,6 @@
 #include "classfile/systemDictionary.hpp"
 #include "oops/oop.inline.hpp"
 #include "prims/jvmtiRedefineClassesTrace.hpp"
-#include "services/classLoadingService.hpp"
 #include "utilities/hashtable.inline.hpp"
 
 
@@ -156,19 +155,7 @@ bool Dictionary::do_unloading() {
           if (k_def_class_loader_data == loader_data) {
             // This is the defining entry, so the referred class is about
             // to be unloaded.
-            // Notify the debugger and clean up the class.
             class_was_unloaded = true;
-            // notify the debugger
-            if (JvmtiExport::should_post_class_unload()) {
-              JvmtiExport::post_class_unload(ik);
-            }
-
-            // notify ClassLoadingService of class unload
-            ClassLoadingService::notify_class_unloaded(ik);
-
-            // Clean up C heap
-            ik->release_C_heap_structures();
-            ik->constants()->release_C_heap_structures();
           }
           // Also remove this system dictionary entry.
           purge_entry = true;

src/share/vm/oops/instanceKlass.cpp

@@ -54,6 +54,7 @@
 #include "runtime/javaCalls.hpp"
 #include "runtime/mutexLocker.hpp"
 #include "runtime/thread.inline.hpp"
+#include "services/classLoadingService.hpp"
 #include "services/threadService.hpp"
 #include "utilities/dtrace.hpp"
 #include "utilities/macros.hpp"
@@ -2312,7 +2313,29 @@ static void clear_all_breakpoints(Method* m) {
   m->clear_all_breakpoints();
 }
 
+
+void InstanceKlass::notify_unload_class(InstanceKlass* ik) {
+  // notify the debugger
+  if (JvmtiExport::should_post_class_unload()) {
+    JvmtiExport::post_class_unload(ik);
+  }
+
+  // notify ClassLoadingService of class unload
+  ClassLoadingService::notify_class_unloaded(ik);
+}
+
+void InstanceKlass::release_C_heap_structures(InstanceKlass* ik) {
+  // Clean up C heap
+  ik->release_C_heap_structures();
+  ik->constants()->release_C_heap_structures();
+}
+
 void InstanceKlass::release_C_heap_structures() {
+
+  // Can't release the constant pool here because the constant pool can be
+  // deallocated separately from the InstanceKlass for default methods and
+  // redefine classes.
+
   // Deallocate oop map cache
   if (_oop_map_cache != NULL) {
     delete _oop_map_cache;

src/share/vm/oops/instanceKlass.hpp

@@ -236,7 +236,7 @@ class InstanceKlass: public Klass {
     _misc_rewritten            = 1 << 0, // methods rewritten.
     _misc_has_nonstatic_fields = 1 << 1, // for sizing with UseCompressedOops
     _misc_should_verify_class  = 1 << 2, // allow caching of preverification
-    _misc_is_anonymous         = 1 << 3, // has embedded _inner_classes field
+    _misc_is_anonymous         = 1 << 3, // has embedded _host_klass field
     _misc_is_contended         = 1 << 4, // marked with contended annotation
     _misc_has_default_methods  = 1 << 5  // class/superclass/implemented interfaces has default methods
   };
@@ -934,7 +934,9 @@ class InstanceKlass: public Klass {
   // referenced by handles.
   bool on_stack() const { return _constants->on_stack(); }
 
-  void release_C_heap_structures();
+  // callbacks for actions during class unloading
+  static void notify_unload_class(InstanceKlass* ik);
+  static void release_C_heap_structures(InstanceKlass* ik);
 
   // Parallel Scavenge and Parallel Old
   PARALLEL_GC_DECLS
@@ -1022,6 +1024,8 @@ private:
   // Returns the array class with this class as element type
   Klass* array_klass_impl(bool or_null, TRAPS);
 
+  // Free CHeap allocated fields.
+  void release_C_heap_structures();
 public:
   // CDS support - remove and restore oops from metadata. Oops are not shared.
   virtual void remove_unshareable_info();