1 /*

     2  * Copyright (c) 2001, 2017, 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_G1_G1MARKSWEEP_HPP

    26 #define SHARE_VM_GC_G1_G1MARKSWEEP_HPP

    27 

    28 #include "gc/g1/g1CollectedHeap.hpp"

    29 #include "gc/g1/heapRegion.hpp"

    30 #include "gc/serial/genMarkSweep.hpp"

    31 #include "gc/shared/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 class G1ArchiveRegionMap;

    48 

    49 class G1MarkSweep : AllStatic {

    50  public:

    51 

    52   static void invoke_at_safepoint(ReferenceProcessor* rp,

    53                                   bool clear_all_softrefs);

    54 

    55   static STWGCTimer* gc_timer();

    56   static SerialOldTracer* gc_tracer();

    57 

    58 private:

    59   // Mark live objects

    60   static void mark_sweep_phase1(bool& marked_for_deopt,

    61                                 bool clear_all_softrefs);

    62   // Calculate new addresses

    63   static void mark_sweep_phase2();

    64   // Update pointers

    65   static void mark_sweep_phase3();

    66   // Move objects to new positions

    67   static void mark_sweep_phase4();

    68 

    69   static void allocate_stacks();

    70   static void prepare_compaction();

    71   static void prepare_compaction_work(G1PrepareCompactClosure* blk);

    72 };

    73 

    74 class G1PrepareCompactClosure : public HeapRegionClosure {

    75  protected:

    76   G1CollectedHeap* _g1h;

    77   ModRefBarrierSet* _mrbs;

    78   CompactPoint _cp;

    79   uint _humongous_regions_removed;

    80 

    81   virtual void prepare_for_compaction(HeapRegion* hr, HeapWord* end);

    82   void prepare_for_compaction_work(CompactPoint* cp, HeapRegion* hr, HeapWord* end);

    83   void free_humongous_region(HeapRegion* hr);

    84   bool is_cp_initialized() const { return _cp.space != NULL; }

    85 

    86  public:

    87   G1PrepareCompactClosure() :

    88     _g1h(G1CollectedHeap::heap()),

    89     _mrbs(_g1h->g1_barrier_set()),

    90     _humongous_regions_removed(0) { }

    91 

    92   void update_sets();

    93   bool doHeapRegion(HeapRegion* hr);

    94 };

    95 

    96 #endif // SHARE_VM_GC_G1_G1MARKSWEEP_HPP