1 /*
   2  * Copyright (c) 2001, 2013, 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_G1_G1MARKSWEEP_HPP
  26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1MARKSWEEP_HPP
  27 
  28 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
  29 #include "gc_implementation/g1/heapRegion.hpp"
  30 #include "memory/genMarkSweep.hpp"
  31 #include "memory/generation.hpp"
  32 #include "memory/universe.hpp"
  33 #include "oops/markOop.hpp"
  34 #include "oops/oop.hpp"
  35 #include "runtime/timer.hpp"
  36 #include "utilities/growableArray.hpp"
  37 
  38 class ReferenceProcessor;
  39 
  40 // G1MarkSweep takes care of global mark-compact garbage collection for a
  41 // G1CollectedHeap using a four-phase pointer forwarding algorithm.  All
  42 // generations are assumed to support marking; those that can also support
  43 // compaction.
  44 //
  45 // Class unloading will only occur when a full gc is invoked.
  46 class G1PrepareCompactClosure;
  47 
  48 class G1MarkSweep : AllStatic {
  49   friend class VM_G1MarkSweep;
  50   friend class Scavenge;
  51 
  52  public:
  53 
  54   static void invoke_at_safepoint(ReferenceProcessor* rp,
  55                                   bool clear_all_softrefs);
  56 
  57   static STWGCTimer* gc_timer() { return GenMarkSweep::_gc_timer; }
  58   static SerialOldTracer* gc_tracer() { return GenMarkSweep::_gc_tracer; }
  59 
  60  private:
  61 
  62   // Mark live objects
  63   static void mark_sweep_phase1(bool& marked_for_deopt,
  64                                 bool clear_all_softrefs);
  65   // Calculate new addresses
  66   static void mark_sweep_phase2();
  67   // Update pointers
  68   static void mark_sweep_phase3();
  69   // Move objects to new positions
  70   static void mark_sweep_phase4();
  71 
  72   static void allocate_stacks();
  73   static void prepare_compaction();
  74   static void prepare_compaction_work(G1PrepareCompactClosure* blk);
  75 };
  76 
  77 class G1PrepareCompactClosure : public HeapRegionClosure {
  78  protected:
  79   G1CollectedHeap* _g1h;
  80   ModRefBarrierSet* _mrbs;
  81   CompactPoint _cp;
  82   HeapRegionSetCount _humongous_regions_removed;
  83 
  84   virtual void prepare_for_compaction(HeapRegion* hr, HeapWord* end);
  85   void prepare_for_compaction_work(CompactPoint* cp, HeapRegion* hr, HeapWord* end);
  86   void free_humongous_region(HeapRegion* hr);
  87   bool is_cp_initialized() const { return _cp.space != NULL; }
  88 
  89  public:
  90   G1PrepareCompactClosure() :
  91     _g1h(G1CollectedHeap::heap()),
  92     _mrbs(_g1h->g1_barrier_set()),
  93     _humongous_regions_removed() { }
  94 
  95   void update_sets();
  96   bool doHeapRegion(HeapRegion* hr);
  97 };
  98 
  99 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1MARKSWEEP_HPP