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.
22 *
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
36 class PSYoungGen : public CHeapObj<mtGC> {
37 friend class VMStructs;
38 friend class ParallelScavengeHeap;
39 friend class AdjoiningGenerations;
40
41 protected:
42 MemRegion _reserved;
43 PSVirtualSpace* _virtual_space;
44
45 // Spaces
46 MutableSpace* _eden_space;
47 MutableSpace* _from_space;
48 MutableSpace* _to_space;
49
50
51 // MarkSweep Decorators
52 PSMarkSweepDecorator* _eden_mark_sweep;
53 PSMarkSweepDecorator* _from_mark_sweep;
54 PSMarkSweepDecorator* _to_mark_sweep;
55
56 // Sizing information, in bytes, set in constructor
57 const size_t _init_gen_size;
58 const size_t _min_gen_size;
59 const size_t _max_gen_size;
60
61 // Performance counters
62 PSGenerationCounters* _gen_counters;
63 SpaceCounters* _eden_counters;
64 SpaceCounters* _from_counters;
65 SpaceCounters* _to_counters;
66
67 // Initialize the space boundaries
68 void compute_initial_space_boundaries();
69
70 // Space boundary helper
71 void set_space_boundaries(size_t eden_size, size_t survivor_size);
72
73 virtual bool resize_generation(size_t eden_size, size_t survivor_size);
74 virtual void resize_spaces(size_t eden_size, size_t survivor_size);
75
76 // Adjust the spaces to be consistent with the virtual space.
77 void post_resize();
78
79 // Return number of bytes that the generation can change.
80 // These should not be used by PSYoungGen
81 virtual size_t available_for_expansion();
82 virtual size_t available_for_contraction();
83
84 // Given a desired shrinkage in the size of the young generation,
85 // return the actual size available for shrinkage.
86 virtual size_t limit_gen_shrink(size_t desired_change);
87 // returns the number of bytes available from the current size
88 // down to the minimum generation size.
89 size_t available_to_min_gen();
90 // Return the number of bytes available for shrinkage considering
91 // the location the live data in the generation.
92 virtual size_t available_to_live();
93
94 public:
95 // Initialize the generation.
96 PSYoungGen(size_t initial_byte_size,
97 size_t minimum_byte_size,
98 size_t maximum_byte_size);
99 void initialize_work();
100 virtual void initialize(ReservedSpace rs, size_t alignment);
101 virtual void initialize_virtual_space(ReservedSpace rs, size_t alignment);
102
103 MemRegion reserved() const { return _reserved; }
104
105 bool is_in(const void* p) const {
106 return _virtual_space->contains((void *)p);
107 }
108
109 bool is_in_reserved(const void* p) const {
110 return reserved().contains((void *)p);
111 }
112
113 MutableSpace* eden_space() const { return _eden_space; }
114 MutableSpace* from_space() const { return _from_space; }
115 MutableSpace* to_space() const { return _to_space; }
116 PSVirtualSpace* virtual_space() const { return _virtual_space; }
117
118 // For Adaptive size policy
119 size_t min_gen_size() { return _min_gen_size; }
120
121 // MarkSweep support
122 PSMarkSweepDecorator* eden_mark_sweep() const { return _eden_mark_sweep; }
123 PSMarkSweepDecorator* from_mark_sweep() const { return _from_mark_sweep; }
124 PSMarkSweepDecorator* to_mark_sweep() const { return _to_mark_sweep; }
125
126 #if INCLUDE_SERIALGC
127 void precompact();
128 void adjust_pointers();
129 void compact();
130 #endif
131
132 // Called during/after GC
133 void swap_spaces();
134
135 // Resize generation using suggested free space size and survivor size
136 // NOTE: "eden_size" and "survivor_size" are suggestions only. Current
137 // heap layout (particularly, live objects in from space) might
138 // not allow us to use these values.
139 void resize(size_t eden_size, size_t survivor_size);
140
141 // Size info
142 size_t capacity_in_bytes() const;
143 size_t used_in_bytes() const;
144 size_t free_in_bytes() const;
145
146 size_t capacity_in_words() const;
147 size_t used_in_words() const;
148 size_t free_in_words() const;
149
150 // The max this generation can grow to
151 size_t max_size() const { return _reserved.byte_size(); }
152
153 // The max this generation can grow to if the boundary between
154 // the generations are allowed to move.
155 size_t gen_size_limit() const { return _max_gen_size; }
156
157 bool is_maximal_no_gc() const {
158 return true; // Never expands except at a GC
159 }
160
161 // Allocation
162 HeapWord* allocate(size_t word_size) {
163 HeapWord* result = eden_space()->cas_allocate(word_size);
164 return result;
165 }
166
167 HeapWord* volatile* top_addr() const { return eden_space()->top_addr(); }
168 HeapWord** end_addr() const { return eden_space()->end_addr(); }
169
170 // Iteration.
171 void oop_iterate(ExtendedOopClosure* cl);
172 void object_iterate(ObjectClosure* cl);
173
174 virtual void reset_after_change();
175 virtual void reset_survivors_after_shrink();
176
177 // Performance Counter support
178 void update_counters();
179
180 // Debugging - do not use for time critical operations
181 void print() const;
182 void print_on(outputStream* st) const;
183 void print_used_change(size_t prev_used) const;
184 virtual const char* name() const { return "PSYoungGen"; }
185
186 void verify();
187
188 // Space boundary invariant checker
189 void space_invariants() PRODUCT_RETURN;
190
191 // Helper for mangling survivor spaces.
192 void mangle_survivors(MutableSpace* s1,
193 MemRegion s1MR,
194 MutableSpace* s2,
195 MemRegion s2MR) PRODUCT_RETURN;
196
197 void record_spaces_top() PRODUCT_RETURN;
198 };
199
200 #endif // SHARE_VM_GC_PARALLEL_PSYOUNGGEN_HPP