1 /*
 2  * Copyright (c) 2016, 2020, 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_SHENANDOAHCOLLECTIONSET_HPP
26 #define SHARE_GC_SHENANDOAH_SHENANDOAHCOLLECTIONSET_HPP
27 
28 #include "memory/allocation.hpp"
29 #include "memory/virtualspace.hpp"
30 #include "gc/shenandoah/shenandoahHeap.hpp"
31 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
32 #include "gc/shenandoah/shenandoahPadding.hpp"
33 
34 class ShenandoahCollectionSet : public CHeapObj<mtGC> {
35   friend class ShenandoahHeap;
36 private:
37   size_t const          _map_size;
38   size_t const          _region_size_bytes_shift;
39   ReservedSpace         _map_space;
40   char* const           _cset_map;
41   // Bias cset map's base address for fast test if an oop is in cset
42   char* const           _biased_cset_map;
43 
44   ShenandoahHeap* const _heap;
45 
46   bool                  _has_old_regions;
47   size_t                _garbage;
48   size_t                _used;
49   size_t                _region_count;
50 
51   shenandoah_padding(0);
52   volatile size_t       _current_index;
53   shenandoah_padding(1);
54 
55 public:
56   ShenandoahCollectionSet(ShenandoahHeap* heap, ReservedSpace space, char* heap_base);
57 
58   // Add region to collection set
59   void add_region(ShenandoahHeapRegion* r);
60 
61   // MT version
62   ShenandoahHeapRegion* claim_next();
63 
64   // Single-thread version
65   ShenandoahHeapRegion* next();
66 
67   size_t count()  const { return _region_count; }
68   bool is_empty() const { return _region_count == 0; }
69 
70   void clear_current_index() {
71     _current_index = 0;
72   }
73 
74   inline bool is_in(ShenandoahHeapRegion* r) const;
75   inline bool is_in(size_t region_idx)       const;
76   inline bool is_in(oop obj)                 const;
77   inline bool is_in_loc(void* loc)           const;
78 
79   void print_on(outputStream* out) const;
80 
81   bool has_old_regions() const { return _has_old_regions; }
82   size_t used()          const { return _used; }
83 
84   size_t garbage()       const { return _garbage; }
85   void clear();
86 
87 private:
88   char* map_address() const {
89     return _cset_map;
90   }
91   char* biased_map_address() const {
92     return _biased_cset_map;
93   }
94 };
95 
96 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHCOLLECTIONSET_HPP