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