8315998: Remove dead ClassLoaderDataGraphKlassIteratorStatic

Reviewed-by: coleenp

src/hotspot/share/classfile/classLoaderData.cpp

@@ -558,9 +558,6 @@ void ClassLoaderData::initialize_holder(Handle loader_or_mirror) {
 void ClassLoaderData::remove_class(Klass* scratch_class) {
   assert_locked_or_safepoint(ClassLoaderDataGraph_lock);
 
-  // Adjust global class iterator.
-  ClassLoaderDataGraph::adjust_saved_class(scratch_class);
-
   Klass* prev = nullptr;
   for (Klass* k = _klasses; k != nullptr; k = k->next_link()) {
     if (k == scratch_class) {
@@ -620,9 +617,6 @@ void ClassLoaderData::unload() {
   if (_jmethod_ids != nullptr) {
     Method::clear_jmethod_ids(this);
   }
-
-  // Clean up global class iterator for compiler
-  ClassLoaderDataGraph::adjust_saved_class(this);
 }
 
 ModuleEntryTable* ClassLoaderData::modules() {

src/hotspot/share/classfile/classLoaderDataGraph.cpp

@@ -80,85 +80,6 @@ void ClassLoaderDataGraph::verify_claimed_marks_cleared(int claim) {
 #endif
 }
 
-// Class iterator used by the compiler.  It gets some number of classes at
-// a safepoint to decay invocation counters on the methods.
-class ClassLoaderDataGraphKlassIteratorStatic {
-  ClassLoaderData* _current_loader_data;
-  Klass*           _current_class_entry;
- public:
-
-  ClassLoaderDataGraphKlassIteratorStatic() : _current_loader_data(nullptr), _current_class_entry(nullptr) {}
-
-  InstanceKlass* try_get_next_class() {
-    assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
-    size_t max_classes = ClassLoaderDataGraph::num_instance_classes();
-    assert(max_classes > 0, "should not be called with no instance classes");
-    for (size_t i = 0; i < max_classes; ) {
-
-      if (_current_class_entry != nullptr) {
-        Klass* k = _current_class_entry;
-        _current_class_entry = _current_class_entry->next_link();
-
-        if (k->is_instance_klass()) {
-          InstanceKlass* ik = InstanceKlass::cast(k);
-          i++;  // count all instance classes found
-          // Not yet loaded classes are counted in max_classes
-          // but only return loaded classes.
-          if (ik->is_loaded()) {
-            return ik;
-          }
-        }
-      } else {
-        // Go to next CLD
-        if (_current_loader_data != nullptr) {
-          _current_loader_data = _current_loader_data->next();
-        }
-        // Start at the beginning
-        if (_current_loader_data == nullptr) {
-          _current_loader_data = ClassLoaderDataGraph::_head;
-        }
-
-        _current_class_entry = _current_loader_data->klasses();
-      }
-    }
-    // Should never be reached unless all instance classes have failed or are not fully loaded.
-    // Caller handles null.
-    return nullptr;
-  }
-
-  // If the current class for the static iterator is a class being unloaded or
-  // deallocated, adjust the current class.
-  void adjust_saved_class(ClassLoaderData* cld) {
-    if (_current_loader_data == cld) {
-      _current_loader_data = cld->next();
-      if (_current_loader_data != nullptr) {
-        _current_class_entry = _current_loader_data->klasses();
-      }  // else try_get_next_class will start at the head
-    }
-  }
-
-  void adjust_saved_class(Klass* klass) {
-    if (_current_class_entry == klass) {
-      _current_class_entry = klass->next_link();
-    }
-  }
-};
-
-static ClassLoaderDataGraphKlassIteratorStatic static_klass_iterator;
-
-InstanceKlass* ClassLoaderDataGraph::try_get_next_class() {
-  assert(SafepointSynchronize::is_at_safepoint(), "only called at safepoint");
-  return static_klass_iterator.try_get_next_class();
-}
-
-void ClassLoaderDataGraph::adjust_saved_class(ClassLoaderData* cld) {
-  return static_klass_iterator.adjust_saved_class(cld);
-}
-
-void ClassLoaderDataGraph::adjust_saved_class(Klass* klass) {
-  return static_klass_iterator.adjust_saved_class(klass);
-}
-
 void ClassLoaderDataGraph::clean_deallocate_lists(bool walk_previous_versions) {
   assert(SafepointSynchronize::is_at_safepoint(), "must only be called at safepoint");
   uint loaders_processed = 0;

src/hotspot/share/classfile/classLoaderDataGraph.hpp

@@ -97,11 +97,6 @@ class ClassLoaderDataGraph : public AllStatic {
   // Called from VMOperation
   static void walk_metadata_and_clean_metaspaces();
 
-  // VM_CounterDecay iteration support
-  static InstanceKlass* try_get_next_class();
-  static void adjust_saved_class(ClassLoaderData* cld);
-  static void adjust_saved_class(Klass* klass);
-
   static void verify_dictionary();
   static void print_dictionary(outputStream* st);
   static void print_table_statistics(outputStream* st);

src/hotspot/share/interpreter/invocationCounter.cpp

@@ -59,10 +59,6 @@ void InvocationCounter::reset() {
   update(0);
 }
 
-void InvocationCounter::decay() {
-  update(count() >> 1);
-}
-
 void InvocationCounter::print() {
   uint counter = raw_counter();
   tty->print_cr("invocation count: up = %d, limit = " INTX_FORMAT ", carry = %s",

src/hotspot/share/interpreter/invocationCounter.hpp

@@ -60,7 +60,6 @@ class InvocationCounter {
   // Manipulation
   void reset();
   void init();
-  void decay();                                  // decay counter (divide by two)
   void set_carry_on_overflow();
   void set(uint count);
   void increment()                 { _counter += count_increment; }