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 "memory/space.hpp"
28
29 class ShenandoahHeapRegion : public ContiguousSpace {
30 private:
31 static Monitor _mem_protect_lock;
32
33 private:
34 static size_t RegionSizeBytes;
35 static size_t RegionSizeShift;
36
37 private:
38 ShenandoahHeap* _heap;
39 size_t _region_number;
40 volatile jint _live_data;
41 MemRegion reserved;
42
43 bool _humongous_start;
44 bool _humongous_continuation;
45
46 bool _recycled;
47
48 HeapWord* _new_top;
49
50 volatile jint _critical_pins;
51
52 #ifdef ASSERT
53 int _mem_protection_level;
54 #endif
55
56 public:
57 ShenandoahHeapRegion(ShenandoahHeap* heap, HeapWord* start, size_t regionSize, size_t index);
58
59 static void setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size);
60
61 inline static size_t region_size_bytes() {
62 return ShenandoahHeapRegion::RegionSizeBytes;
63 }
64
65 inline static size_t region_size_shift() {
66 return ShenandoahHeapRegion::RegionSizeShift;
67 }
68
69 // Convert to jint with sanity checking
70 inline static jint region_size_bytes_jint() {
71 assert (ShenandoahHeapRegion::RegionSizeBytes <= (size_t)max_jint, "sanity");
72 return (jint)ShenandoahHeapRegion::RegionSizeBytes;
73 }
74
75 // Convert to jint with sanity checking
76 inline static jint region_size_shift_jint() {
77 assert (ShenandoahHeapRegion::RegionSizeShift <= (size_t)max_jint, "sanity");
78 return (jint)ShenandoahHeapRegion::RegionSizeShift;
79 }
80
81 size_t region_number() const;
82
83 // Roll back the previous allocation of an object with specified size.
84 // Returns TRUE when successful, FALSE if not successful or not supported.
85 bool rollback_allocation(uint size);
86
87 void clear_live_data();
88 void set_live_data(size_t s);
89 inline void increase_live_data_words(size_t s);
90 inline void increase_live_data_words(jint s);
91
92 void set_recently_allocated(bool value);
93 bool is_recently_allocated() const;
94
95 bool has_live() const;
96 size_t get_live_data_bytes() const;
97 size_t get_live_data_words() const;
98
99 void print_on(outputStream* st) const;
100
101 size_t garbage() const;
102
103 void recycle();
104
105 void oop_iterate_skip_unreachable(ExtendedOopClosure* cl, bool skip_unreachable_objects);
106
107 void object_iterate_interruptible(ObjectClosure* blk, bool allow_cancel);
108
109 HeapWord* object_iterate_careful(ObjectClosureCareful* cl);
110
111 HeapWord* block_start_const(const void* p) const;
112
113 // Just before GC we need to fill the current region.
114 void fill_region();
115
116 bool in_collection_set() const;
117
118 void set_in_collection_set(bool b);
119
120 void set_humongous_start(bool start);
121 void set_humongous_continuation(bool continuation);
122
123 bool is_humongous() const;
124 bool is_humongous_start() const;
125 bool is_humongous_continuation() const;
126
127 #ifdef ASSERT
128 void memProtectionOn();
129 void memProtectionOff();
130 #endif
131
132 // The following are for humongous regions. We need to save the
133 markOop saved_mark_word;
134 void save_mark_word(oop obj) {saved_mark_word = obj->mark();}
135 markOop mark_word() {return saved_mark_word;}
136
137 void set_new_top(HeapWord* new_top) { _new_top = new_top; }
138 HeapWord* new_top() const { return _new_top; }
139
140 void pin();
141 void unpin();
142
143 bool is_pinned();
144
145 };
146
147 #endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEAPREGION_HPP