1 /*
2 * Copyright (c) 2001, 2015, 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_IMPLEMENTATION_PARALLELSCAVENGE_PSOLDGEN_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSOLDGEN_HPP
27
28 #include "gc_implementation/parallelScavenge/objectStartArray.hpp"
29 #include "gc_implementation/parallelScavenge/psGenerationCounters.hpp"
30 #include "gc_implementation/parallelScavenge/psVirtualspace.hpp"
31 #include "gc_implementation/shared/mutableSpace.hpp"
32 #include "gc_implementation/shared/spaceCounters.hpp"
33 #include "runtime/safepoint.hpp"
34
35 class PSMarkSweepDecorator;
36
37 class PSOldGen : public CHeapObj<mtGC> {
38 friend class VMStructs;
39 friend class PSPromotionManager; // Uses the cas_allocate methods
40 friend class ParallelScavengeHeap;
41 friend class AdjoiningGenerations;
42
43 protected:
44 MemRegion _reserved; // Used for simple containment tests
45 PSVirtualSpace* _virtual_space; // Controls mapping and unmapping of virtual mem
46 ObjectStartArray _start_array; // Keeps track of where objects start in a 512b block
47 MutableSpace* _object_space; // Where all the objects live
48 PSMarkSweepDecorator* _object_mark_sweep; // The mark sweep view of _object_space
49 const char* const _name; // Name of this generation.
50
51 // Performance Counters
52 PSGenerationCounters* _gen_counters;
53 SpaceCounters* _space_counters;
54
55 // Sizing information, in bytes, set in constructor
56 const size_t _init_gen_size;
57 const size_t _min_gen_size;
58 const size_t _max_gen_size;
59
60 // Used when initializing the _name field.
61 static inline const char* select_name();
62
63 #ifdef ASSERT
64 #define assert_block_in_covered_region(_block_start_, _word_size_) \
65 do { \
66 MemRegion __covered_region__ = this->start_array()->covered_region(); \
67 MemRegion __new_memregion__(_block_start_, _word_size_); \
68 MemRegion __used__ = this->object_space()->used_region(); \
69 assert(__covered_region__.contains(__new_memregion__), \
70 err_msg("new region is not in covered_region [ "PTR_FORMAT", "PTR_FORMAT" ], " \
71 "new region [ "PTR_FORMAT", "PTR_FORMAT" ], " \
72 "object space [ "PTR_FORMAT", "PTR_FORMAT" ]", \
73 p2i(__covered_region__.start()), \
74 p2i(__covered_region__.end()), \
75 p2i(__new_memregion__.start()), \
76 p2i(__new_memregion__.end()), \
77 p2i(__used__.start()), \
78 p2i(__used__.end()))); \
79 } while (0)
80 #else
81 #define assert_block_in_covered_region(_block_start_, _word_size_)
82 #endif
83
84 HeapWord* allocate_noexpand(size_t word_size) {
85 // We assume the heap lock is held here.
86 assert_locked_or_safepoint(Heap_lock);
87 HeapWord* res = object_space()->allocate(word_size);
88 if (res != NULL) {
89 assert_block_in_covered_region(res, word_size);
90 _start_array.allocate_block(res);
91 }
92 return res;
93 }
94
95 // Support for MT garbage collection. CAS allocation is lower overhead than grabbing
96 // and releasing the heap lock, which is held during gc's anyway. This method is not
97 // safe for use at the same time as allocate_noexpand()!
98 HeapWord* cas_allocate_noexpand(size_t word_size) {
99 assert(SafepointSynchronize::is_at_safepoint(), "Must only be called at safepoint");
100 HeapWord* res = object_space()->cas_allocate(word_size);
101 if (res != NULL) {
102 assert_block_in_covered_region(res, word_size);
103 _start_array.allocate_block(res);
104 }
105 return res;
106 }
107
108 // Support for MT garbage collection. See above comment.
109 HeapWord* cas_allocate(size_t word_size) {
110 HeapWord* res = cas_allocate_noexpand(word_size);
111 return (res == NULL) ? expand_and_cas_allocate(word_size) : res;
112 }
113
114 HeapWord* expand_and_allocate(size_t word_size);
115 HeapWord* expand_and_cas_allocate(size_t word_size);
116 void expand(size_t bytes);
117 bool expand_by(size_t bytes);
118 bool expand_to_reserved();
119
120 void shrink(size_t bytes);
121
122 void post_resize();
123
124 public:
125 // Initialize the generation.
126 PSOldGen(ReservedSpace rs, size_t alignment,
127 size_t initial_size, size_t min_size, size_t max_size,
128 const char* perf_data_name, int level);
129
130 PSOldGen(size_t initial_size, size_t min_size, size_t max_size,
131 const char* perf_data_name, int level);
132
133 virtual void initialize(ReservedSpace rs, size_t alignment,
134 const char* perf_data_name, int level);
135 void initialize_virtual_space(ReservedSpace rs, size_t alignment);
136 virtual void initialize_work(const char* perf_data_name, int level);
137 virtual void initialize_performance_counters(const char* perf_data_name, int level);
138
139 MemRegion reserved() const { return _reserved; }
140 virtual size_t max_gen_size() { return _max_gen_size; }
141 size_t min_gen_size() { return _min_gen_size; }
142
143 // Returns limit on the maximum size of the generation. This
144 // is the same as _max_gen_size for PSOldGen but need not be
145 // for a derived class.
146 virtual size_t gen_size_limit();
147
148 bool is_in(const void* p) const {
149 return _virtual_space->contains((void *)p);
150 }
151
152 bool is_in_reserved(const void* p) const {
153 return reserved().contains(p);
154 }
155
156 MutableSpace* object_space() const { return _object_space; }
157 PSMarkSweepDecorator* object_mark_sweep() const { return _object_mark_sweep; }
158 ObjectStartArray* start_array() { return &_start_array; }
159 PSVirtualSpace* virtual_space() const { return _virtual_space;}
160
161 // Has the generation been successfully allocated?
162 bool is_allocated();
163
164 // MarkSweep methods
165 virtual void precompact();
166 void adjust_pointers();
167 void compact();
168
169 // Size info
170 size_t capacity_in_bytes() const { return object_space()->capacity_in_bytes(); }
171 size_t used_in_bytes() const { return object_space()->used_in_bytes(); }
172 size_t free_in_bytes() const { return object_space()->free_in_bytes(); }
173
174 size_t capacity_in_words() const { return object_space()->capacity_in_words(); }
175 size_t used_in_words() const { return object_space()->used_in_words(); }
176 size_t free_in_words() const { return object_space()->free_in_words(); }
177
178 // Includes uncommitted memory
179 size_t contiguous_available() const;
180
181 bool is_maximal_no_gc() const {
182 return virtual_space()->uncommitted_size() == 0;
183 }
184
185 // Calculating new sizes
186 void resize(size_t desired_free_space);
187
188 // Allocation. We report all successful allocations to the size policy
189 // Note that the perm gen does not use this method, and should not!
190 HeapWord* allocate(size_t word_size);
191
192 // Iteration.
193 void oop_iterate_no_header(OopClosure* cl) { object_space()->oop_iterate_no_header(cl); }
194 void object_iterate(ObjectClosure* cl) { object_space()->object_iterate(cl); }
195
196 // Debugging - do not use for time critical operations
197 virtual void print() const;
198 virtual void print_on(outputStream* st) const;
199 void print_used_change(size_t prev_used) const;
200
201 void verify();
202 void verify_object_start_array();
203
204 // These should not used
205 virtual void reset_after_change();
206
207 // These should not used
208 virtual size_t available_for_expansion();
209 virtual size_t available_for_contraction();
210
211 void space_invariants() PRODUCT_RETURN;
212
213 // Performance Counter support
214 void update_counters();
215
216 // Printing support
217 virtual const char* name() const { return _name; }
218
219 // Debugging support
220 // Save the tops of all spaces for later use during mangling.
221 void record_spaces_top() PRODUCT_RETURN;
222 };
223
224 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSOLDGEN_HPP