1 /*
2 * Copyright (c) 2013, 2015, Red Hat, Inc. and/or its affiliates.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This code is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 * version 2 for more details (a copy is included in the LICENSE file that
12 * accompanied this code).
13 *
14 * You should have received a copy of the GNU General Public License version
15 * 2 along with this work; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 * or visit www.oracle.com if you need additional information or have any
20 * questions.
21 *
22 */
23
24 #ifndef SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEAPREGION_HPP
25 #define SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEAPREGION_HPP
26
27 #include "gc/shared/space.hpp"
28 #include "memory/universe.hpp"
29 #include "utilities/sizes.hpp"
30
31 class ShenandoahHeapRegion : public ContiguousSpace {
32 private:
33 static Monitor _mem_protect_lock;
34
35 public:
36 static size_t RegionSizeBytes;
37 static size_t RegionSizeShift;
38
39 private:
40 ShenandoahHeap* _heap;
41 size_t _region_number;
42 volatile jint _live_data;
43 MemRegion reserved;
44
45 bool _humongous_start;
46 bool _humongous_continuation;
47 bool _humongous_obj_array;
48
49 bool _recycled;
50 bool _root;
51
52 HeapWord* _new_top;
53
54 volatile jint _critical_pins;
55
56 #ifdef ASSERT
57 int _mem_protection_level;
58 #endif
59
60 public:
61 ShenandoahHeapRegion(ShenandoahHeap* heap, HeapWord* start, size_t regionSize, size_t index);
62
63 static void setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size);
64
65 size_t region_number() const;
66
67 // Allocation (return NULL if full)
68 inline HeapWord* allocate(size_t word_size);
69
70 // Roll back the previous allocation of an object with specified size.
71 // Returns TRUE when successful, FALSE if not successful or not supported.
72 bool rollback_allocation(uint size);
73
74 void clear_live_data();
75 void set_live_data(size_t s);
76 inline void increase_live_data_words(jint s);
77
78 void set_recently_allocated(bool value);
79 bool is_recently_allocated() const;
80
81 bool has_live() const;
82 size_t get_live_data_bytes() const;
83 size_t get_live_data_words() const;
84
85 void print_on(outputStream* st) const;
86
87 size_t garbage() const;
88
89 void recycle();
90
91 void object_iterate_interruptible(ObjectClosure* blk, bool allow_cancel);
92
93 HeapWord* object_iterate_careful(ObjectClosureCareful* cl);
94 void oop_iterate(ExtendedOopClosure* cl);
95
96 private:
97 void oop_iterate_objects(ExtendedOopClosure* cl);
98 void oop_iterate_humongous(ExtendedOopClosure* cl);
99
100 public:
101 HeapWord* block_start_const(const void* p) const;
102
103 // Just before GC we need to fill the current region.
104 void fill_region();
105
106 bool in_collection_set() const;
107
108 void set_in_collection_set(bool b);
109
110 void set_humongous_start(bool start);
111 void set_humongous_continuation(bool continuation);
112 void set_humongous_obj_array(bool obj_array);
113
114 bool is_humongous() const;
115 bool is_humongous_start() const;
116 bool is_humongous_continuation() const;
117 bool is_humongous_obj_array() const;
118
119 #ifdef ASSERT
120 void memProtectionOn();
121 void memProtectionOff();
122 #endif
123
124 // The following are for humongous regions. We need to save the
125 markOop saved_mark_word;
126 void save_mark_word(oop obj) {saved_mark_word = obj->mark();}
127 markOop mark_word() {return saved_mark_word;}
128
129 virtual CompactibleSpace* next_compaction_space() const;
130
131 // Override for scan_and_forward support.
132 void prepare_for_compaction(CompactPoint* cp);
133 void adjust_pointers();
134 void compact();
135
136 void set_new_top(HeapWord* new_top) { _new_top = new_top; }
137 HeapWord* new_top() const { return _new_top; }
138
139 void pin();
140 void unpin();
141
142 bool is_pinned();
143
144 void set_root(bool r) {
145 _root = r;
146 }
147 bool is_root() {
148 return _root;
149 }
150 };
151
152 #endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEAPREGION_HPP