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_PARALLEL_PSOLDGEN_HPP
26 #define SHARE_VM_GC_PARALLEL_PSOLDGEN_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 #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 #if INCLUDE_SERIALGC
49 PSMarkSweepDecorator* _object_mark_sweep; // The mark sweep view of _object_space
50 #endif
51 const char* const _name; // Name of this generation.
52
53 // Performance Counters
54 PSGenerationCounters* _gen_counters;
55 SpaceCounters* _space_counters;
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 // Used when initializing the _name field.
63 static inline const char* select_name();
64
65 #ifdef ASSERT
66 void assert_block_in_covered_region(MemRegion new_memregion) {
67 // Explictly capture current covered_region in a local
68 MemRegion covered_region = this->start_array()->covered_region();
69 assert(covered_region.contains(new_memregion),
70 "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(this->object_space()->used_region().start()),
78 p2i(this->object_space()->used_region().end()));
79 }
80 #endif
81
82 HeapWord* allocate_noexpand(size_t word_size) {
83 // We assume the heap lock is held here.
84 assert_locked_or_safepoint(Heap_lock);
85 HeapWord* res = object_space()->allocate(word_size);
86 if (res != NULL) {
87 DEBUG_ONLY(assert_block_in_covered_region(MemRegion(res, word_size)));
88 _start_array.allocate_block(res);
89 }
90 return res;
91 }
92
93 // Support for MT garbage collection. CAS allocation is lower overhead than grabbing
94 // and releasing the heap lock, which is held during gc's anyway. This method is not
95 // safe for use at the same time as allocate_noexpand()!
96 HeapWord* cas_allocate_noexpand(size_t word_size) {
97 assert(SafepointSynchronize::is_at_safepoint(), "Must only be called at safepoint");
98 HeapWord* res = object_space()->cas_allocate(word_size);
99 if (res != NULL) {
100 DEBUG_ONLY(assert_block_in_covered_region(MemRegion(res, word_size)));
101 _start_array.allocate_block(res);
102 }
103 return res;
104 }
105
106 // Support for MT garbage collection. See above comment.
107 HeapWord* cas_allocate(size_t word_size) {
108 HeapWord* res = cas_allocate_noexpand(word_size);
109 return (res == NULL) ? expand_and_cas_allocate(word_size) : res;
110 }
111
112 HeapWord* expand_and_allocate(size_t word_size);
113 HeapWord* expand_and_cas_allocate(size_t word_size);
114 void expand(size_t bytes);
115 bool expand_by(size_t bytes);
116 bool expand_to_reserved();
117
118 void shrink(size_t bytes);
119
120 void post_resize();
121
122 public:
123 // Initialize the generation.
124 PSOldGen(ReservedSpace rs, size_t alignment,
125 size_t initial_size, size_t min_size, size_t max_size,
126 const char* perf_data_name, int level);
127
128 PSOldGen(size_t initial_size, size_t min_size, size_t max_size,
129 const char* perf_data_name, int level);
130
131 virtual void initialize(ReservedSpace rs, size_t alignment,
132 const char* perf_data_name, int level);
133 void initialize_virtual_space(ReservedSpace rs, size_t alignment);
134 virtual void initialize_work(const char* perf_data_name, int level);
135 virtual void initialize_performance_counters(const char* perf_data_name, int level);
136
137 MemRegion reserved() const { return _reserved; }
138 virtual size_t max_gen_size() { return _max_gen_size; }
139 size_t min_gen_size() { return _min_gen_size; }
140
141 // Returns limit on the maximum size of the generation. This
142 // is the same as _max_gen_size for PSOldGen but need not be
143 // for a derived class.
144 virtual size_t gen_size_limit();
145
146 bool is_in(const void* p) const {
147 return _virtual_space->contains((void *)p);
148 }
149
150 bool is_in_reserved(const void* p) const {
151 return reserved().contains(p);
152 }
153
154 MutableSpace* object_space() const { return _object_space; }
155 #if INCLUDE_SERIALGC
156 PSMarkSweepDecorator* object_mark_sweep() const { return _object_mark_sweep; }
157 #endif
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 #if INCLUDE_SERIALGC
165 // MarkSweep methods
166 virtual void precompact();
167 void adjust_pointers();
168 void compact();
169 #endif
170
171 // Size info
172 size_t capacity_in_bytes() const { return object_space()->capacity_in_bytes(); }
173 size_t used_in_bytes() const { return object_space()->used_in_bytes(); }
174 size_t free_in_bytes() const { return object_space()->free_in_bytes(); }
175
176 size_t capacity_in_words() const { return object_space()->capacity_in_words(); }
177 size_t used_in_words() const { return object_space()->used_in_words(); }
178 size_t free_in_words() const { return object_space()->free_in_words(); }
179
180 // Includes uncommitted memory
181 size_t contiguous_available() const;
182
183 bool is_maximal_no_gc() const {
184 return virtual_space()->uncommitted_size() == 0;
185 }
186
187 // Calculating new sizes
188 void resize(size_t desired_free_space);
189
190 // Allocation. We report all successful allocations to the size policy
191 // Note that the perm gen does not use this method, and should not!
192 HeapWord* allocate(size_t word_size);
193
194 // Iteration.
195 void oop_iterate(OopIterateClosure* cl) { object_space()->oop_iterate(cl); }
196 void object_iterate(ObjectClosure* cl) { object_space()->object_iterate(cl); }
197
198 // Debugging - do not use for time critical operations
199 virtual void print() const;
200 virtual void print_on(outputStream* st) const;
201 void print_used_change(size_t prev_used) const;
202
203 void verify();
204 void verify_object_start_array();
205
206 // These should not used
207 virtual void reset_after_change();
208
209 // These should not used
210 virtual size_t available_for_expansion();
211 virtual size_t available_for_contraction();
212
213 void space_invariants() PRODUCT_RETURN;
214
215 // Performance Counter support
216 void update_counters();
217
218 // Printing support
219 virtual const char* name() const { return _name; }
220
221 // Debugging support
222 // Save the tops of all spaces for later use during mangling.
223 void record_spaces_top() PRODUCT_RETURN;
224 };
225
226 #endif // SHARE_VM_GC_PARALLEL_PSOLDGEN_HPP