1 /*
 2  * Copyright (c) 2021, Red Hat, Inc. 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
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23  */
24 
25 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHDEGENERATEDGC_HPP
26 #define SHARE_GC_SHENANDOAH_SHENANDOAHDEGENERATEDGC_HPP
27 
28 #include "gc/shenandoah/shenandoahGC.hpp"
29 
30 class VM_ShenandoahDegeneratedGC;
31 class ShenandoahGeneration;
32 
33 class ShenandoahDegenGC : public ShenandoahGC {
34   friend class VM_ShenandoahDegeneratedGC;
35 private:
36   const ShenandoahDegenPoint  _degen_point;
37   ShenandoahGeneration* _generation;
38   bool _abbreviated;
39 
40 public:
41   ShenandoahDegenGC(ShenandoahDegenPoint degen_point, ShenandoahGeneration* generation);
42   bool collect(GCCause::Cause cause);
43 
44 private:
45   void vmop_degenerated();
46   void entry_degenerated();
47   void op_degenerated();
48 
49   void op_reset();
50   void op_mark();
51   void op_finish_mark();
52   void op_prepare_evacuation();
53   void op_cleanup_early();
54 
55   void op_evacuate();
56   void op_init_updaterefs();
57   void op_updaterefs();
58   void op_update_roots();
59   void op_cleanup_complete();
60 
61   // Fail handling
62   void op_degenerated_futile();
63   void op_degenerated_fail();
64 
65   // Turns this degenerated cycle into a full gc without leaving the safepoint
66   void upgrade_to_full();
67 
68   const char* degen_event_message(ShenandoahDegenPoint point) const;
69 
70   bool has_in_place_promotions(const ShenandoahHeap* heap) const;
71 };
72 
73 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHDEGENERATEDGC_HPP