8211446: Replace oop_pc_follow_contents with oop_iterate and closure

Reviewed-by: sjohanss, tschatzl

src/hotspot/share/gc/parallel/pcTasks.cpp

@@ -35,6 +35,7 @@
 #include "gc/shared/gcTimer.hpp"
 #include "gc/shared/gcTraceTime.inline.hpp"
 #include "logging/log.hpp"
+#include "memory/iterator.inline.hpp"
 #include "memory/resourceArea.hpp"
 #include "memory/universe.hpp"
 #include "oops/objArrayKlass.inline.hpp"
@@ -58,7 +59,7 @@ void ThreadRootsMarkingTask::do_it(GCTaskManager* manager, uint which) {
   ParCompactionManager* cm =
     ParCompactionManager::gc_thread_compaction_manager(which);
 
-  ParCompactionManager::MarkAndPushClosure mark_and_push_closure(cm);
+  PCMarkAndPushClosure mark_and_push_closure(cm);
   MarkingCodeBlobClosure mark_and_push_in_blobs(&mark_and_push_closure, !CodeBlobToOopClosure::FixRelocations);
 
   _thread->oops_do(&mark_and_push_closure, &mark_and_push_in_blobs);
@@ -73,7 +74,7 @@ void MarkFromRootsTask::do_it(GCTaskManager* manager, uint which) {
 
   ParCompactionManager* cm =
     ParCompactionManager::gc_thread_compaction_manager(which);
-  ParCompactionManager::MarkAndPushClosure mark_and_push_closure(cm);
+  PCMarkAndPushClosure mark_and_push_closure(cm);
 
   switch (_root_type) {
     case universe:
@@ -139,7 +140,7 @@ void RefProcTaskProxy::do_it(GCTaskManager* manager, uint which)
 
   ParCompactionManager* cm =
     ParCompactionManager::gc_thread_compaction_manager(which);
-  ParCompactionManager::MarkAndPushClosure mark_and_push_closure(cm);
+  PCMarkAndPushClosure mark_and_push_closure(cm);
   ParCompactionManager::FollowStackClosure follow_stack_closure(cm);
   _rp_task.work(_work_id, *PSParallelCompact::is_alive_closure(),
                 mark_and_push_closure, follow_stack_closure);
@@ -182,13 +183,12 @@ void StealMarkingTask::do_it(GCTaskManager* manager, uint which) {
 
   ParCompactionManager* cm =
     ParCompactionManager::gc_thread_compaction_manager(which);
-  ParCompactionManager::MarkAndPushClosure mark_and_push_closure(cm);
 
   oop obj = NULL;
   ObjArrayTask task;
   do {
     while (ParCompactionManager::steal_objarray(which,  task)) {
-      cm->follow_contents((objArrayOop)task.obj(), task.index());
+      cm->follow_array((objArrayOop)task.obj(), task.index());
       cm->follow_marking_stacks();
     }
     while (ParCompactionManager::steal(which, obj)) {

src/hotspot/share/gc/parallel/psCompactionManager.cpp

@@ -132,113 +132,6 @@ ParCompactionManager::gc_thread_compaction_manager(uint index) {
   return _manager_array[index];
 }
 
-void InstanceKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
-  assert(obj != NULL, "can't follow the content of NULL object");
-
-  cm->follow_klass(this);
-  // Only mark the header and let the scan of the meta-data mark
-  // everything else.
-
-  ParCompactionManager::MarkAndPushClosure cl(cm);
-  if (UseCompressedOops) {
-    InstanceKlass::oop_oop_iterate_oop_maps<narrowOop>(obj, &cl);
-  } else {
-    InstanceKlass::oop_oop_iterate_oop_maps<oop>(obj, &cl);
-  }
-}
-
-void InstanceMirrorKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
-  InstanceKlass::oop_pc_follow_contents(obj, cm);
-
-  // Follow the klass field in the mirror.
-  Klass* klass = java_lang_Class::as_Klass(obj);
-  if (klass != NULL) {
-    // An unsafe anonymous class doesn't have its own class loader,
-    // so the call to follow_klass will mark and push its java mirror instead of the
-    // class loader. When handling the java mirror for an unsafe anonymous
-    // class we need to make sure its class loader data is claimed, this is done
-    // by calling follow_class_loader explicitly. For non-anonymous classes the
-    // call to follow_class_loader is made when the class loader itself is handled.
-    if (klass->is_instance_klass() &&
-        InstanceKlass::cast(klass)->is_unsafe_anonymous()) {
-      cm->follow_class_loader(klass->class_loader_data());
-    } else {
-      cm->follow_klass(klass);
-    }
-  } else {
-    // If klass is NULL then this a mirror for a primitive type.
-    // We don't have to follow them, since they are handled as strong
-    // roots in Universe::oops_do.
-    assert(java_lang_Class::is_primitive(obj), "Sanity check");
-  }
-
-  ParCompactionManager::MarkAndPushClosure cl(cm);
-  if (UseCompressedOops) {
-    oop_oop_iterate_statics<narrowOop>(obj, &cl);
-  } else {
-    oop_oop_iterate_statics<oop>(obj, &cl);
-  }
-}
-
-void InstanceClassLoaderKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
-  InstanceKlass::oop_pc_follow_contents(obj, cm);
-
-  ClassLoaderData * const loader_data = java_lang_ClassLoader::loader_data_acquire(obj);
-  if (loader_data != NULL) {
-    cm->follow_class_loader(loader_data);
-  }
-}
-
-template <class T>
-static void oop_pc_follow_contents_specialized(InstanceRefKlass* klass, oop obj, ParCompactionManager* cm) {
-  T* referent_addr = (T*)java_lang_ref_Reference::referent_addr_raw(obj);
-  T heap_oop = RawAccess<>::oop_load(referent_addr);
-  log_develop_trace(gc, ref)("InstanceRefKlass::oop_pc_follow_contents " PTR_FORMAT, p2i(obj));
-  if (!CompressedOops::is_null(heap_oop)) {
-    oop referent = CompressedOops::decode_not_null(heap_oop);
-    if (PSParallelCompact::mark_bitmap()->is_unmarked(referent) &&
-        PSParallelCompact::ref_processor()->discover_reference(obj, klass->reference_type())) {
-      // reference already enqueued, referent will be traversed later
-      klass->InstanceKlass::oop_pc_follow_contents(obj, cm);
-      log_develop_trace(gc, ref)("       Non NULL enqueued " PTR_FORMAT, p2i(obj));
-      return;
-    } else {
-      // treat referent as normal oop
-      log_develop_trace(gc, ref)("       Non NULL normal " PTR_FORMAT, p2i(obj));
-      cm->mark_and_push(referent_addr);
-    }
-  }
-  // Treat discovered as normal oop.
-  T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr_raw(obj);
-  cm->mark_and_push(discovered_addr);
-  klass->InstanceKlass::oop_pc_follow_contents(obj, cm);
-}
-
-
-void InstanceRefKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
-  if (UseCompressedOops) {
-    oop_pc_follow_contents_specialized<narrowOop>(this, obj, cm);
-  } else {
-    oop_pc_follow_contents_specialized<oop>(this, obj, cm);
-  }
-}
-
-void ObjArrayKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
-  cm->follow_klass(this);
-
-  if (UseCompressedOops) {
-    oop_pc_follow_contents_specialized<narrowOop>(objArrayOop(obj), 0, cm);
-  } else {
-    oop_pc_follow_contents_specialized<oop>(objArrayOop(obj), 0, cm);
-  }
-}
-
-void TypeArrayKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
-  assert(obj->is_typeArray(),"must be a type array");
-  // Performance tweak: We skip iterating over the klass pointer since we
-  // know that Universe::TypeArrayKlass never moves.
-}
-
 void ParCompactionManager::follow_marking_stacks() {
   do {
     // Drain the overflow stack first, to allow stealing from the marking stack.
@@ -253,7 +146,7 @@ void ParCompactionManager::follow_marking_stacks() {
     // Process ObjArrays one at a time to avoid marking stack bloat.
     ObjArrayTask task;
     if (_objarray_stack.pop_overflow(task) || _objarray_stack.pop_local(task)) {
-      follow_contents((objArrayOop)task.obj(), task.index());
+      follow_array((objArrayOop)task.obj(), task.index());
     }
   } while (!marking_stacks_empty());
 

src/hotspot/share/gc/parallel/psCompactionManager.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2018, 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
@@ -171,24 +171,10 @@ private:
   void drain_region_stacks();
 
   void follow_contents(oop obj);
-  void follow_contents(objArrayOop array, int index);
+  void follow_array(objArrayOop array, int index);
 
   void update_contents(oop obj);
 
-  class MarkAndPushClosure: public BasicOopIterateClosure {
-   private:
-    ParCompactionManager* _compaction_manager;
-   public:
-    MarkAndPushClosure(ParCompactionManager* cm) : _compaction_manager(cm) { }
-
-    template <typename T> void do_oop_work(T* p);
-    virtual void do_oop(oop* p);
-    virtual void do_oop(narrowOop* p);
-
-    // This closure provides its own oop verification code.
-    debug_only(virtual bool should_verify_oops() { return false; })
-  };
-
   class FollowStackClosure: public VoidClosure {
    private:
     ParCompactionManager* _compaction_manager;

src/hotspot/share/gc/parallel/psCompactionManager.inline.hpp

@@ -25,6 +25,7 @@
 #ifndef SHARE_VM_GC_PARALLEL_PSCOMPACTIONMANAGER_INLINE_HPP
 #define SHARE_VM_GC_PARALLEL_PSCOMPACTIONMANAGER_INLINE_HPP
 
+#include "classfile/javaClasses.inline.hpp"
 #include "gc/parallel/parMarkBitMap.hpp"
 #include "gc/parallel/psCompactionManager.hpp"
 #include "gc/parallel/psParallelCompact.inline.hpp"
@@ -37,6 +38,37 @@
 #include "utilities/debug.hpp"
 #include "utilities/globalDefinitions.hpp"
 
+class PCMarkAndPushClosure: public OopClosure {
+private:
+  ParCompactionManager* _compaction_manager;
+public:
+  PCMarkAndPushClosure(ParCompactionManager* cm) : _compaction_manager(cm) { }
+
+  template <typename T> void do_oop_nv(T* p)      { _compaction_manager->mark_and_push(p); }
+  virtual void do_oop(oop* p)                     { do_oop_nv(p); }
+  virtual void do_oop(narrowOop* p)               { do_oop_nv(p); }
+
+  // This closure provides its own oop verification code.
+  debug_only(virtual bool should_verify_oops()    { return false; })
+};
+
+class PCIterateMarkAndPushClosure: public MetadataVisitingOopIterateClosure {
+private:
+  ParCompactionManager* _compaction_manager;
+public:
+  PCIterateMarkAndPushClosure(ParCompactionManager* cm, ReferenceProcessor* rp) : MetadataVisitingOopIterateClosure(rp), _compaction_manager(cm) { }
+
+  template <typename T> void do_oop_nv(T* p)      { _compaction_manager->mark_and_push(p); }
+  virtual void do_oop(oop* p)                     { do_oop_nv(p); }
+  virtual void do_oop(narrowOop* p)               { do_oop_nv(p); }
+
+  void do_klass_nv(Klass* k)                      { _compaction_manager->follow_klass(k); }
+  void do_cld_nv(ClassLoaderData* cld)            { _compaction_manager->follow_class_loader(cld); }
+
+  // This closure provides its own oop verification code.
+  debug_only(virtual bool should_verify_oops()    { return false; })
+};
+
 inline bool ParCompactionManager::steal(int queue_num, oop& t) {
   return stack_array()->steal(queue_num, t);
 }
@@ -84,14 +116,6 @@ inline void ParCompactionManager::mark_and_push(T* p) {
   }
 }
 
-template <typename T>
-inline void ParCompactionManager::MarkAndPushClosure::do_oop_work(T* p) {
-  _compaction_manager->mark_and_push(p);
-}
-
-inline void ParCompactionManager::MarkAndPushClosure::do_oop(oop* p)       { do_oop_work(p); }
-inline void ParCompactionManager::MarkAndPushClosure::do_oop(narrowOop* p) { do_oop_work(p); }
-
 inline void ParCompactionManager::follow_klass(Klass* klass) {
   oop holder = klass->klass_holder();
   mark_and_push(&holder);
@@ -101,19 +125,8 @@ inline void ParCompactionManager::FollowStackClosure::do_void() {
   _compaction_manager->follow_marking_stacks();
 }
 
-inline void ParCompactionManager::follow_class_loader(ClassLoaderData* cld) {
+template <typename T>
-  MarkAndPushClosure mark_and_push_closure(this);
+inline void follow_array_specialized(objArrayOop obj, int index, ParCompactionManager* cm) {
-
-  cld->oops_do(&mark_and_push_closure, true);
-}
-
-inline void ParCompactionManager::follow_contents(oop obj) {
-  assert(PSParallelCompact::mark_bitmap()->is_marked(obj), "should be marked");
-  obj->pc_follow_contents(this);
-}
-
-template <class T>
-inline void oop_pc_follow_contents_specialized(objArrayOop obj, int index, ParCompactionManager* cm) {
   const size_t len = size_t(obj->length());
   const size_t beg_index = size_t(index);
   assert(beg_index < len || len == 0, "index too large");
@@ -134,11 +147,11 @@ inline void oop_pc_follow_contents_specialized(objArrayOop obj, int index, ParCo
   }
 }
 
-inline void ParCompactionManager::follow_contents(objArrayOop obj, int index) {
+inline void ParCompactionManager::follow_array(objArrayOop obj, int index) {
   if (UseCompressedOops) {
-    oop_pc_follow_contents_specialized<narrowOop>(obj, index, this);
+    follow_array_specialized<narrowOop>(obj, index, this);
   } else {
-    oop_pc_follow_contents_specialized<oop>(obj, index, this);
+    follow_array_specialized<oop>(obj, index, this);
   }
 }
 
@@ -146,4 +159,19 @@ inline void ParCompactionManager::update_contents(oop obj) {
   obj->pc_update_contents(this);
 }
 
+inline void ParCompactionManager::follow_class_loader(ClassLoaderData* cld) {
+  PCMarkAndPushClosure mark_and_push_closure(this);
+  cld->oops_do(&mark_and_push_closure, true);
+}
+
+inline void ParCompactionManager::follow_contents(oop obj) {
+  assert(PSParallelCompact::mark_bitmap()->is_marked(obj), "should be marked");
+  if (obj->is_objArray()) {
+    follow_array(objArrayOop(obj), 0);
+  } else {
+    PCIterateMarkAndPushClosure cl(this, PSParallelCompact::ref_processor());
+    obj->oop_iterate(&cl);
+  }
+}
+
 #endif // SHARE_VM_GC_PARALLEL_PSCOMPACTIONMANAGER_INLINE_HPP

src/hotspot/share/gc/parallel/psParallelCompact.cpp

@@ -846,18 +846,43 @@ PSParallelCompact::IsAliveClosure PSParallelCompact::_is_alive_closure;
 
 bool PSParallelCompact::IsAliveClosure::do_object_b(oop p) { return mark_bitmap()->is_marked(p); }
 
-void PSParallelCompact::post_initialize() {
+class PCReferenceProcessor: public ReferenceProcessor {
-  ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
+public:
-  _span_based_discoverer.set_span(heap->reserved_region());
+  PCReferenceProcessor(
-  _ref_processor =
+    BoolObjectClosure* is_subject_to_discovery,
-    new ReferenceProcessor(&_span_based_discoverer,
+    BoolObjectClosure* is_alive_non_header) :
+      ReferenceProcessor(is_subject_to_discovery,
       ParallelRefProcEnabled && (ParallelGCThreads > 1), // mt processing
       ParallelGCThreads,   // mt processing degree
       true,                // mt discovery
       ParallelGCThreads,   // mt discovery degree
       true,                // atomic_discovery
-                           &_is_alive_closure,  // non-header is alive closure
+      is_alive_non_header) {
-                           false);              // disable adjusting number of processing threads
+  }
+
+  template<typename T> bool discover(oop obj, ReferenceType type) {
+    T* referent_addr = (T*) java_lang_ref_Reference::referent_addr_raw(obj);
+    T heap_oop = RawAccess<>::oop_load(referent_addr);
+    oop referent = CompressedOops::decode_not_null(heap_oop);
+    return PSParallelCompact::mark_bitmap()->is_unmarked(referent)
+        && ReferenceProcessor::discover_reference(obj, type);
+  }
+  virtual bool discover_reference(oop obj, ReferenceType type) {
+    if (UseCompressedOops) {
+      return discover<narrowOop>(obj, type);
+    } else {
+      return discover<oop>(obj, type);
+    }
+  }
+};
+
+void PSParallelCompact::post_initialize() {
+  ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
+  _span_based_discoverer.set_span(heap->reserved_region());
+  _ref_processor =
+    new PCReferenceProcessor(&_span_based_discoverer,
+                             &_is_alive_closure); // non-header is alive closure
+
   _counters = new CollectorCounters("PSParallelCompact", 1);
 
   // Initialize static fields in ParCompactionManager.
@@ -2077,7 +2102,7 @@ void PSParallelCompact::marking_phase(ParCompactionManager* cm,
   TaskQueueSetSuper* qset = ParCompactionManager::stack_array();
   ParallelTaskTerminator terminator(active_gc_threads, qset);
 
-  ParCompactionManager::MarkAndPushClosure mark_and_push_closure(cm);
+  PCMarkAndPushClosure mark_and_push_closure(cm);
   ParCompactionManager::FollowStackClosure follow_stack_closure(cm);
 
   // Need new claim bits before marking starts.

src/hotspot/share/oops/instanceClassLoaderKlass.hpp

@@ -52,7 +52,6 @@ public:
   //
 #if INCLUDE_PARALLELGC
   // Parallel Compact
-  void oop_pc_follow_contents(oop obj, ParCompactionManager* cm);
   void oop_pc_update_pointers(oop obj, ParCompactionManager* cm);
 #endif
 

src/hotspot/share/oops/instanceKlass.hpp

@@ -1187,7 +1187,6 @@ public:
   //
 #if INCLUDE_PARALLELGC
   // Parallel Compact
-  void oop_pc_follow_contents(oop obj, ParCompactionManager* cm);
   void oop_pc_update_pointers(oop obj, ParCompactionManager* cm);
 #endif
 

src/hotspot/share/oops/instanceMirrorKlass.hpp

@@ -93,7 +93,6 @@ class InstanceMirrorKlass: public InstanceKlass {
   //
 #if INCLUDE_PARALLELGC
   // Parallel Compact
-  void oop_pc_follow_contents(oop obj, ParCompactionManager* cm);
   void oop_pc_update_pointers(oop obj, ParCompactionManager* cm);
 #endif
 

src/hotspot/share/oops/instanceRefKlass.hpp

@@ -62,7 +62,6 @@ class InstanceRefKlass: public InstanceKlass {
   //
 #if INCLUDE_PARALLELGC
   // Parallel Compact
-  void oop_pc_follow_contents(oop obj, ParCompactionManager* cm);
   void oop_pc_update_pointers(oop obj, ParCompactionManager* cm);
 #endif
 

src/hotspot/share/oops/klass.hpp

@@ -677,7 +677,6 @@ protected:
   //
 #if INCLUDE_PARALLELGC
   // Parallel Compact
-  virtual void oop_pc_follow_contents(oop obj, ParCompactionManager* cm) = 0;
   virtual void oop_pc_update_pointers(oop obj, ParCompactionManager* cm) = 0;
 #endif
 

src/hotspot/share/oops/objArrayKlass.hpp

@@ -124,7 +124,6 @@ class ObjArrayKlass : public ArrayKlass {
   //
 #if INCLUDE_PARALLELGC
   // Parallel Compact
-  void oop_pc_follow_contents(oop obj, ParCompactionManager* cm);
   void oop_pc_update_pointers(oop obj, ParCompactionManager* cm);
 #endif
 

src/hotspot/share/oops/oop.hpp

@@ -289,7 +289,6 @@ class oopDesc {
 
 #if INCLUDE_PARALLELGC
   // Parallel Compact
-  inline void pc_follow_contents(ParCompactionManager* cm);
   inline void pc_update_contents(ParCompactionManager* cm);
 #endif
 

src/hotspot/share/oops/oop.inline.hpp

@@ -427,9 +427,6 @@ void oopDesc::incr_age() {
 }
 
 #if INCLUDE_PARALLELGC
-void oopDesc::pc_follow_contents(ParCompactionManager* cm) {
-  klass()->oop_pc_follow_contents(this, cm);
-}
 
 void oopDesc::pc_update_contents(ParCompactionManager* cm) {
   Klass* k = klass();

src/hotspot/share/oops/typeArrayKlass.hpp

@@ -79,7 +79,6 @@ class TypeArrayKlass : public ArrayKlass {
 
 #if INCLUDE_PARALLELGC
   // Parallel Compact
-  void oop_pc_follow_contents(oop obj, ParCompactionManager* cm);
   void oop_pc_update_pointers(oop obj, ParCompactionManager* cm);
 #endif