1 /*
 2  * Copyright (c) 2018, 2019, 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
21  * questions.
22  *
23  */
24 
25 #ifndef SHARE_GC_SHENANDOAH_HEURISTICS_SHENANDOAHCOMPACTHEURISTICS_HPP
26 #define SHARE_GC_SHENANDOAH_HEURISTICS_SHENANDOAHCOMPACTHEURISTICS_HPP
27 
28 #include "gc/shenandoah/heuristics/shenandoahHeuristics.hpp"
29 
30 /*
31  * This heuristic has simpler triggers than the adaptive heuristic. The
32  * size of the collection set is limited to 3/4 of available memory.
33  */
34 class ShenandoahCompactHeuristics : public ShenandoahHeuristics {
35 public:
36   ShenandoahCompactHeuristics(ShenandoahSpaceInfo* space_info);
37 
38   virtual bool should_start_gc();
39 
40   virtual void choose_collection_set_from_regiondata(ShenandoahCollectionSet* cset,
41                                                      RegionData* data, size_t size,
42                                                      size_t actual_free);
43 
44   virtual const char* name()     { return "Compact"; }
45   virtual bool is_diagnostic()   { return false; }
46   virtual bool is_experimental() { return false; }
47 };
48 
49 #endif // SHARE_GC_SHENANDOAH_HEURISTICS_SHENANDOAHCOMPACTHEURISTICS_HPP