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.
22 *
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 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 void assert_block_in_covered_region(MemRegion new_memregion) {
65 // Explictly capture current covered_region in a local
66 MemRegion covered_region = this->start_array()->covered_region();
67 assert(covered_region.contains(new_memregion),
68 "new region is not in covered_region [ " PTR_FORMAT ", " PTR_FORMAT " ], "
69 "new region [ " PTR_FORMAT ", " PTR_FORMAT " ], "
70 "object space [ " PTR_FORMAT ", " PTR_FORMAT " ]",
71 p2i(covered_region.start()),
72 p2i(covered_region.end()),
73 p2i(new_memregion.start()),
74 p2i(new_memregion.end()),
75 p2i(this->object_space()->used_region().start()),
76 p2i(this->object_space()->used_region().end()));
77 }
78 #endif
79
80 HeapWord* allocate_noexpand(size_t word_size) {
81 // We assume the heap lock is held here.
82 assert_locked_or_safepoint(Heap_lock);
83 HeapWord* res = object_space()->allocate(word_size);
84 if (res != NULL) {
85 DEBUG_ONLY(assert_block_in_covered_region(MemRegion(res, word_size)));
86 _start_array.allocate_block(res);
87 }
88 return res;
89 }
90
91 // Support for MT garbage collection. CAS allocation is lower overhead than grabbing
92 // and releasing the heap lock, which is held during gc's anyway. This method is not
93 // safe for use at the same time as allocate_noexpand()!
94 HeapWord* cas_allocate_noexpand(size_t word_size) {
95 assert(SafepointSynchronize::is_at_safepoint(), "Must only be called at safepoint");
96 HeapWord* res = object_space()->cas_allocate(word_size);
97 if (res != NULL) {
98 DEBUG_ONLY(assert_block_in_covered_region(MemRegion(res, word_size)));
99 _start_array.allocate_block(res);
100 }
101 return res;
102 }
103
104 // Support for MT garbage collection. See above comment.
105 HeapWord* cas_allocate(size_t word_size) {
106 HeapWord* res = cas_allocate_noexpand(word_size);
107 return (res == NULL) ? expand_and_cas_allocate(word_size) : res;
108 }
109
110 HeapWord* expand_and_allocate(size_t word_size);
111 HeapWord* expand_and_cas_allocate(size_t word_size);
112 void expand(size_t bytes);
113 bool expand_by(size_t bytes);
114 bool expand_to_reserved();
115
116 void shrink(size_t bytes);
117
118 void post_resize();
119
120 public:
121 // Initialize the generation.
122 PSOldGen(ReservedSpace rs, size_t alignment,
123 size_t initial_size, size_t min_size, size_t max_size,
124 const char* perf_data_name, int level);
125
126 PSOldGen(size_t initial_size, size_t min_size, size_t max_size,
127 const char* perf_data_name, int level);
128
129 virtual void initialize(ReservedSpace rs, size_t alignment,
130 const char* perf_data_name, int level);
131 void initialize_virtual_space(ReservedSpace rs, size_t alignment);
132 virtual void initialize_work(const char* perf_data_name, int level);
133 virtual void initialize_performance_counters(const char* perf_data_name, int level);
134
135 MemRegion reserved() const { return _reserved; }
136 virtual size_t max_gen_size() { return _max_gen_size; }
137 size_t min_gen_size() { return _min_gen_size; }
138
139 // Returns limit on the maximum size of the generation. This
140 // is the same as _max_gen_size for PSOldGen but need not be
141 // for a derived class.
142 virtual size_t gen_size_limit();
143
144 bool is_in(const void* p) const {
145 return _virtual_space->contains((void *)p);
146 }
147
148 bool is_in_reserved(const void* p) const {
149 return reserved().contains(p);
150 }
151
152 MutableSpace* object_space() const { return _object_space; }
153 PSMarkSweepDecorator* object_mark_sweep() const { return _object_mark_sweep; }
154 ObjectStartArray* start_array() { return &_start_array; }
155 PSVirtualSpace* virtual_space() const { return _virtual_space;}
156
157 // Has the generation been successfully allocated?
158 bool is_allocated();
159
160 // MarkSweep methods
161 virtual void precompact();
162 void adjust_pointers();
163 void compact();
164
165 // Size info
166 size_t capacity_in_bytes() const { return object_space()->capacity_in_bytes(); }
167 size_t used_in_bytes() const { return object_space()->used_in_bytes(); }
168 size_t free_in_bytes() const { return object_space()->free_in_bytes(); }
169
170 size_t capacity_in_words() const { return object_space()->capacity_in_words(); }
171 size_t used_in_words() const { return object_space()->used_in_words(); }
172 size_t free_in_words() const { return object_space()->free_in_words(); }
173
174 // Includes uncommitted memory
175 size_t contiguous_available() const;
176
177 bool is_maximal_no_gc() const {
178 return virtual_space()->uncommitted_size() == 0;
179 }
180
181 // Calculating new sizes
182 void resize(size_t desired_free_space);
183
184 // Allocation. We report all successful allocations to the size policy
185 // Note that the perm gen does not use this method, and should not!
186 HeapWord* allocate(size_t word_size);
187
188 // Iteration.
189 void oop_iterate_no_header(OopClosure* cl) { object_space()->oop_iterate_no_header(cl); }
190 void object_iterate(ObjectClosure* cl) { object_space()->object_iterate(cl); }
191
192 // Debugging - do not use for time critical operations
193 virtual void print() const;
194 virtual void print_on(outputStream* st) const;
195 void print_used_change(size_t prev_used) const;
196
197 void verify();
198 void verify_object_start_array();
199
200 // These should not used
201 virtual void reset_after_change();
202
203 // These should not used
204 virtual size_t available_for_expansion();
205 virtual size_t available_for_contraction();
206
207 void space_invariants() PRODUCT_RETURN;
208
209 // Performance Counter support
210 void update_counters();
211
212 // Printing support
213 virtual const char* name() const { return _name; }
214
215 // Debugging support
216 // Save the tops of all spaces for later use during mangling.
217 void record_spaces_top() PRODUCT_RETURN;
218 };
219
220 #endif // SHARE_VM_GC_PARALLEL_PSOLDGEN_HPP