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 /*

  * Copyright (c) 2002, 2012, 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

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  */

 #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_INLINE_HPP

 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_INLINE_HPP

 #include "gc_implementation/parallelScavenge/cardTableExtension.hpp"

 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"

 #include "gc_implementation/parallelScavenge/psPromotionManager.hpp"

 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"

 #include "gc_implementation/parallelScavenge/psScavenge.hpp"

 #include "memory/iterator.hpp"

 inline void PSScavenge::save_to_space_top_before_gc() {

   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();

   _to_space_top_before_gc = heap->young_gen()->to_space()->top();

 }

 template <class T> inline bool PSScavenge::should_scavenge(T* p) {

   T heap_oop = oopDesc::load_heap_oop(p);

   if (oopDesc::is_null(heap_oop)) return false;

   oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);

   return PSScavenge::is_obj_in_young((HeapWord*)obj);

 }

 template <class T>

 inline bool PSScavenge::should_scavenge(T* p, MutableSpace* to_space) {

   if (should_scavenge(p)) {

     oop obj = oopDesc::load_decode_heap_oop_not_null(p);

     // Skip objects copied to to_space since the scavenge started.

     HeapWord* const addr = (HeapWord*)obj;

     return addr < to_space_top_before_gc() || addr >= to_space->end();

   }

   return false;

 }

 template <class T>

 inline bool PSScavenge::should_scavenge(T* p, bool check_to_space) {

   if (check_to_space) {

     ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();

     return should_scavenge(p, heap->young_gen()->to_space());

   }

   return should_scavenge(p);

 }

 // Attempt to "claim" oop at p via CAS, push the new obj if successful

 // This version tests the oop* to make sure it is within the heap before

 // attempting marking.

 template <class T, bool promote_immediately>

 inline void PSScavenge::copy_and_push_safe_barrier(PSPromotionManager* pm,

                                                    T*                  p) {

   assert(should_scavenge(p, true), "revisiting object?");

   oop o = oopDesc::load_decode_heap_oop_not_null(p);

   oop new_obj = o->is_forwarded()

         ? o->forwardee()

         : pm->copy_to_survivor_space<promote_immediately>(o);

 #ifndef PRODUCT

   // This code must come after the CAS test, or it will print incorrect

   // information.

   if (TraceScavenge &&  o->is_forwarded()) {

     gclog_or_tty->print_cr("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",

        "forwarding",

        new_obj->klass()->internal_name(), o, new_obj, new_obj->size());

   }

 #endif

   oopDesc::encode_store_heap_oop_not_null(p, new_obj);

   // We cannot mark without test, as some code passes us pointers

   // that are outside the heap. These pointers are either from roots

   // or from metadata.

   if ((!PSScavenge::is_obj_in_young((HeapWord*)p)) &&

       Universe::heap()->is_in_reserved(p)) {

     if (PSScavenge::is_obj_in_young((HeapWord*)new_obj)) {

       card_table()->inline_write_ref_field_gc(p, new_obj);

     }

   }

 }

 template<bool promote_immediately>

 class PSRootsClosure: public OopClosure {

  private:

   PSPromotionManager* _promotion_manager;

  protected:

   template <class T> void do_oop_work(T *p) {

     if (PSScavenge::should_scavenge(p)) {

       // We never card mark roots, maybe call a func without test?

       PSScavenge::copy_and_push_safe_barrier<T, promote_immediately>(_promotion_manager, p);

     }

   }

  public:

   PSRootsClosure(PSPromotionManager* pm) : _promotion_manager(pm) { }

   void do_oop(oop* p)       { PSRootsClosure::do_oop_work(p); }

   void do_oop(narrowOop* p) { PSRootsClosure::do_oop_work(p); }

 };

 typedef PSRootsClosure</*promote_immediately=*/false> PSScavengeRootsClosure;

 typedef PSRootsClosure</*promote_immediately=*/true> PSPromoteRootsClosure;

 // Scavenges a single oop in a Klass.

 class PSScavengeFromKlassClosure: public OopClosure {

  private:

   PSPromotionManager* _pm;

   // Used to redirty a scanned klass if it has oops

   // pointing to the young generation after being scanned.

   Klass*             _scanned_klass;

  public:

   PSScavengeFromKlassClosure(PSPromotionManager* pm) : _pm(pm), _scanned_klass(NULL) { }

   void do_oop(narrowOop* p) { ShouldNotReachHere(); }

   void do_oop(oop* p)       {

     ParallelScavengeHeap* psh = ParallelScavengeHeap::heap();

     assert(!psh->is_in_reserved(p), "GC barrier needed");

     if (PSScavenge::should_scavenge(p)) {

       assert(!Universe::heap()->is_in_reserved(p), "Not from meta-data?");

       assert(PSScavenge::should_scavenge(p, true), "revisiting object?");

       oop o = *p;

       oop new_obj;

       if (o->is_forwarded()) {

         new_obj = o->forwardee();

       } else {

         new_obj = _pm->copy_to_survivor_space</*promote_immediately=*/false>(o);

       }

       oopDesc::encode_store_heap_oop_not_null(p, new_obj);

       if (PSScavenge::is_obj_in_young((HeapWord*)new_obj)) {

         do_klass_barrier();

       }

     }

   }

   void set_scanned_klass(Klass* klass) {

     assert(_scanned_klass == NULL || klass == NULL, "Should always only handling one klass at a time");

     _scanned_klass = klass;

   }

  private:

   void do_klass_barrier() {

     assert(_scanned_klass != NULL, "Should not be called without having a scanned klass");

     _scanned_klass->record_modified_oops();

   }

 };

 // Scavenges the oop in a Klass.

 class PSScavengeKlassClosure: public KlassClosure {

  private:

   PSScavengeFromKlassClosure _oop_closure;

  protected:

  public:

   PSScavengeKlassClosure(PSPromotionManager* pm) : _oop_closure(pm) { }

   void do_klass(Klass* klass) {

     // If the klass has not been dirtied we know that there's

     // no references into  the young gen and we can skip it.

 #ifndef PRODUCT

     if (TraceScavenge) {

       ResourceMark rm;

       gclog_or_tty->print_cr("PSScavengeKlassClosure::do_klass %p, %s, dirty: %s",

                              klass,

                              klass->external_name(),

                              klass->has_modified_oops() ? "true" : "false");

     }

 #endif

     if (klass->has_modified_oops()) {

       // Clean the klass since we're going to scavenge all the metadata.

       klass->clear_modified_oops();

       // Setup the promotion manager to redirty this klass

       // if references are left in the young gen.

       _oop_closure.set_scanned_klass(klass);

       klass->oops_do(&_oop_closure);

       _oop_closure.set_scanned_klass(NULL);

     }

   }

 };

 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_INLINE_HPP