1 /*
2 * Copyright (c) 2001, 2016, Oracle and/or its affiliates. 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.
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23 */
24
25 #ifndef SHARE_VM_GC_PARALLEL_PSYOUNGGEN_HPP
26 #define SHARE_VM_GC_PARALLEL_PSYOUNGGEN_HPP
27
28 #include "gc/parallel/mutableSpace.hpp"
29 #include "gc/parallel/objectStartArray.hpp"
30 #include "gc/parallel/psGenerationCounters.hpp"
31 #include "gc/parallel/psVirtualspace.hpp"
32 #include "gc/parallel/spaceCounters.hpp"
33
34 class PSMarkSweepDecorator;
35 class MarkSweep;
36
37 class PSYoungGen : public CHeapObj<mtGC> {
38 friend class VMStructs;
39 friend class ParallelScavengeHeap;
40 friend class AdjoiningGenerations;
41
42 protected:
43 MemRegion _reserved;
44 PSVirtualSpace* _virtual_space;
45
46 // Spaces
47 MutableSpace* _eden_space;
48 MutableSpace* _from_space;
49 MutableSpace* _to_space;
50
51
52 // MarkSweep Decorators
53 PSMarkSweepDecorator* _eden_mark_sweep;
54 PSMarkSweepDecorator* _from_mark_sweep;
55 PSMarkSweepDecorator* _to_mark_sweep;
56
57 // Sizing information, in bytes, set in constructor
58 const size_t _init_gen_size;
59 const size_t _min_gen_size;
60 const size_t _max_gen_size;
61
62 // Performance counters
63 PSGenerationCounters* _gen_counters;
64 SpaceCounters* _eden_counters;
65 SpaceCounters* _from_counters;
66 SpaceCounters* _to_counters;
67
68 // Initialize the space boundaries
69 void compute_initial_space_boundaries();
70
71 // Space boundary helper
72 void set_space_boundaries(size_t eden_size, size_t survivor_size);
73
74 virtual bool resize_generation(size_t eden_size, size_t survivor_size);
75 virtual void resize_spaces(size_t eden_size, size_t survivor_size);
76
77 // Adjust the spaces to be consistent with the virtual space.
78 void post_resize();
79
80 // Return number of bytes that the generation can change.
81 // These should not be used by PSYoungGen
82 virtual size_t available_for_expansion();
83 virtual size_t available_for_contraction();
84
85 // Given a desired shrinkage in the size of the young generation,
86 // return the actual size available for shrinkage.
87 virtual size_t limit_gen_shrink(size_t desired_change);
88 // returns the number of bytes available from the current size
89 // down to the minimum generation size.
90 size_t available_to_min_gen();
91 // Return the number of bytes available for shrinkage considering
92 // the location the live data in the generation.
93 virtual size_t available_to_live();
94
95 public:
96 // Initialize the generation.
97 PSYoungGen(size_t initial_byte_size,
98 size_t minimum_byte_size,
99 size_t maximum_byte_size);
100 void initialize_work();
101 virtual void initialize(ReservedSpace rs, size_t alignment);
102 virtual void initialize_virtual_space(ReservedSpace rs, size_t alignment);
103
104 MemRegion reserved() const { return _reserved; }
105
106 bool is_in(const void* p) const {
107 return _virtual_space->contains((void *)p);
108 }
109
110 bool is_in_reserved(const void* p) const {
111 return reserved().contains((void *)p);
112 }
113
114 MutableSpace* eden_space() const { return _eden_space; }
115 MutableSpace* from_space() const { return _from_space; }
116 MutableSpace* to_space() const { return _to_space; }
117 PSVirtualSpace* virtual_space() const { return _virtual_space; }
118
119 // For Adaptive size policy
120 size_t min_gen_size() { return _min_gen_size; }
121
122 // MarkSweep support
123 PSMarkSweepDecorator* eden_mark_sweep() const { return _eden_mark_sweep; }
124 PSMarkSweepDecorator* from_mark_sweep() const { return _from_mark_sweep; }
125 PSMarkSweepDecorator* to_mark_sweep() const { return _to_mark_sweep; }
126
127 void precompact();
128 void adjust_pointers(MarkSweep* ms);
129 void compact();
130
131 // Called during/after GC
132 void swap_spaces();
133
134 // Resize generation using suggested free space size and survivor size
135 // NOTE: "eden_size" and "survivor_size" are suggestions only. Current
136 // heap layout (particularly, live objects in from space) might
137 // not allow us to use these values.
138 void resize(size_t eden_size, size_t survivor_size);
139
140 // Size info
141 size_t capacity_in_bytes() const;
142 size_t used_in_bytes() const;
143 size_t free_in_bytes() const;
144
145 size_t capacity_in_words() const;
146 size_t used_in_words() const;
147 size_t free_in_words() const;
148
149 // The max this generation can grow to
150 size_t max_size() const { return _reserved.byte_size(); }
151
152 // The max this generation can grow to if the boundary between
153 // the generations are allowed to move.
154 size_t gen_size_limit() const { return _max_gen_size; }
155
156 bool is_maximal_no_gc() const {
157 return true; // Never expands except at a GC
158 }
159
160 // Allocation
161 HeapWord* allocate(size_t word_size) {
162 HeapWord* result = eden_space()->cas_allocate(word_size);
163 return result;
164 }
165
166 HeapWord* volatile* top_addr() const { return eden_space()->top_addr(); }
167 HeapWord** end_addr() const { return eden_space()->end_addr(); }
168
169 // Iteration.
170 void oop_iterate(ExtendedOopClosure* cl);
171 void object_iterate(ObjectClosure* cl);
172
173 virtual void reset_after_change();
174 virtual void reset_survivors_after_shrink();
175
176 // Performance Counter support
177 void update_counters();
178
179 // Debugging - do not use for time critical operations
180 void print() const;
181 void print_on(outputStream* st) const;
182 void print_used_change(size_t prev_used) const;
183 virtual const char* name() const { return "PSYoungGen"; }
184
185 void verify();
186
187 // Space boundary invariant checker
188 void space_invariants() PRODUCT_RETURN;
189
190 // Helper for mangling survivor spaces.
191 void mangle_survivors(MutableSpace* s1,
192 MemRegion s1MR,
193 MutableSpace* s2,
194 MemRegion s2MR) PRODUCT_RETURN;
195
196 void record_spaces_top() PRODUCT_RETURN;
197 };
198
199 #endif // SHARE_VM_GC_PARALLEL_PSYOUNGGEN_HPP