1 /*
   2  * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_INLINE_HPP
  26 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_INLINE_HPP
  27 
  28 #include "gc_implementation/parallelScavenge/cardTableExtension.hpp"
  29 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
  30 #include "gc_implementation/parallelScavenge/psPromotionManager.hpp"
  31 #include "gc_implementation/parallelScavenge/psScavenge.hpp"
  32 
  33 inline void PSScavenge::save_to_space_top_before_gc() {
  34   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
  35   _to_space_top_before_gc = heap->young_gen()->to_space()->top();
  36 }
  37 
  38 template <class T> inline bool PSScavenge::should_scavenge(T* p) {
  39   T heap_oop = oopDesc::load_heap_oop(p);
  40   if (oopDesc::is_null(heap_oop)) return false;
  41   oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
  42   return PSScavenge::is_obj_in_young((HeapWord*)obj);
  43 }
  44 
  45 template <class T>
  46 inline bool PSScavenge::should_scavenge(T* p, MutableSpace* to_space) {
  47   if (should_scavenge(p)) {
  48     oop obj = oopDesc::load_decode_heap_oop_not_null(p);
  49     // Skip objects copied to to_space since the scavenge started.
  50     HeapWord* const addr = (HeapWord*)obj;
  51     return addr < to_space_top_before_gc() || addr >= to_space->end();
  52   }
  53   return false;
  54 }
  55 
  56 template <class T>
  57 inline bool PSScavenge::should_scavenge(T* p, bool check_to_space) {
  58   if (check_to_space) {
  59     ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
  60     return should_scavenge(p, heap->young_gen()->to_space());
  61   }
  62   return should_scavenge(p);
  63 }
  64 
  65 // Attempt to "claim" oop at p via CAS, push the new obj if successful
  66 // This version tests the oop* to make sure it is within the heap before
  67 // attempting marking.
  68 template <class T>
  69 inline void PSScavenge::copy_and_push_safe_barrier(PSPromotionManager* pm,
  70                                                    T*                  p) {
  71   assert(should_scavenge(p, true), "revisiting object?");
  72 
  73   oop o = oopDesc::load_decode_heap_oop_not_null(p);
  74   oop new_obj = o->is_forwarded()
  75         ? o->forwardee()
  76         : pm->copy_to_survivor_space(o);
  77   oopDesc::encode_store_heap_oop_not_null(p, new_obj);
  78 
  79   // We cannot mark without test, as some code passes us pointers
  80   // that are outside the heap.
  81   if ((!PSScavenge::is_obj_in_young((HeapWord*)p)) &&
  82       Universe::heap()->is_in_reserved(p)) {
  83     if (PSScavenge::is_obj_in_young((HeapWord*)new_obj)) {
  84       card_table()->inline_write_ref_field_gc(p, new_obj);
  85     }
  86   }
  87 }
  88 
  89 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_INLINE_HPP