1 /*
   2  * Copyright (c) 2005, 2012, 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_OOPS_OOP_PCGC_INLINE_HPP
  26 #define SHARE_VM_OOPS_OOP_PCGC_INLINE_HPP
  27 
  28 #include "utilities/macros.hpp"
  29 #if INCLUDE_ALL_GCS
  30 #include "gc_implementation/parNew/parNewGeneration.hpp"
  31 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
  32 #include "gc_implementation/parallelScavenge/psCompactionManager.hpp"
  33 #include "gc_implementation/parallelScavenge/psParallelCompact.hpp"
  34 #include "gc_implementation/parallelScavenge/psScavenge.hpp"
  35 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
  36 #endif // INCLUDE_ALL_GCS
  37 
  38 inline void oopDesc::update_contents(ParCompactionManager* cm) {
  39   // The klass field must be updated before anything else
  40   // can be done.
  41   DEBUG_ONLY(Klass* original_klass = klass());
  42 
  43   Klass* new_klass = klass();
  44   if (!new_klass->oop_is_typeArray()) {
  45     // It might contain oops beyond the header, so take the virtual call.
  46     new_klass->oop_update_pointers(cm, this);
  47   }
  48   // Else skip it.  The TypeArrayKlass in the header never needs scavenging.
  49 }
  50 
  51 inline void oopDesc::follow_contents(ParCompactionManager* cm) {
  52   assert (PSParallelCompact::mark_bitmap()->is_marked(this),
  53     "should be marked");
  54   klass()->oop_follow_contents(cm, this);
  55 }
  56 
  57 // Used by parallel old GC.
  58 
  59 inline oop oopDesc::forward_to_atomic(oop p) {
  60   assert(ParNewGeneration::is_legal_forward_ptr(p),
  61          "illegal forwarding pointer value.");
  62   markOop oldMark = mark();
  63   markOop forwardPtrMark = markOopDesc::encode_pointer_as_mark(p);
  64   markOop curMark;
  65 
  66   assert(forwardPtrMark->decode_pointer() == p, "encoding must be reversable");
  67   assert(sizeof(markOop) == sizeof(intptr_t), "CAS below requires this.");
  68 
  69   while (!oldMark->is_marked()) {
  70     curMark = (markOop)Atomic::cmpxchg_ptr(forwardPtrMark, &_mark, oldMark);
  71     assert(is_forwarded(), "object should have been forwarded");
  72     if (curMark == oldMark) {
  73       return NULL;
  74     }
  75     // If the CAS was unsuccessful then curMark->is_marked()
  76     // should return true as another thread has CAS'd in another
  77     // forwarding pointer.
  78     oldMark = curMark;
  79   }
  80   return forwardee();
  81 }
  82 
  83 inline void oopDesc::update_header(ParCompactionManager* cm) {
  84   PSParallelCompact::adjust_klass(cm, klass());
  85 }
  86 
  87 #endif // SHARE_VM_OOPS_OOP_PCGC_INLINE_HPP