1 /*
2 * Copyright (c) 2001, 2012, 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_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 _start_array.allocate_block(res);
69 }
70 return res;
71 }
72
73 // Support for MT garbage collection. CAS allocation is lower overhead than grabbing
74 // and releasing the heap lock, which is held during gc's anyway. This method is not
75 // safe for use at the same time as allocate_noexpand()!
76 HeapWord* cas_allocate_noexpand(size_t word_size) {
77 assert(SafepointSynchronize::is_at_safepoint(), "Must only be called at safepoint");
78 HeapWord* res = object_space()->cas_allocate(word_size);
79 if (res != NULL) {
80 _start_array.allocate_block(res);
81 }
82 return res;
83 }
84
85 // Support for MT garbage collection. See above comment.
86 HeapWord* cas_allocate(size_t word_size) {
87 HeapWord* res = cas_allocate_noexpand(word_size);
88 return (res == NULL) ? expand_and_cas_allocate(word_size) : res;
89 }
90
91 HeapWord* expand_and_allocate(size_t word_size);
92 HeapWord* expand_and_cas_allocate(size_t word_size);
93 void expand(size_t bytes);
94 bool expand_by(size_t bytes);
95 bool expand_to_reserved();
96
97 void shrink(size_t bytes);
98
99 void post_resize();
100
101 public:
102 // Initialize the generation.
103 PSOldGen(ReservedSpace rs, size_t alignment,
104 size_t initial_size, size_t min_size, size_t max_size,
105 const char* perf_data_name, int level);
106
107 PSOldGen(size_t initial_size, size_t min_size, size_t max_size,
108 const char* perf_data_name, int level);
109
110 virtual void initialize(ReservedSpace rs, size_t alignment,
111 const char* perf_data_name, int level);
112 void initialize_virtual_space(ReservedSpace rs, size_t alignment);
113 virtual void initialize_work(const char* perf_data_name, int level);
114 virtual void initialize_performance_counters(const char* perf_data_name, int level);
115
116 MemRegion reserved() const { return _reserved; }
117 virtual size_t max_gen_size() { return _max_gen_size; }
118 size_t min_gen_size() { return _min_gen_size; }
119
120 // Returns limit on the maximum size of the generation. This
121 // is the same as _max_gen_size for PSOldGen but need not be
122 // for a derived class.
123 virtual size_t gen_size_limit();
124
125 bool is_in(const void* p) const {
126 return _virtual_space->contains((void *)p);
127 }
128
129 bool is_in_reserved(const void* p) const {
130 return reserved().contains(p);
131 }
132
133 MutableSpace* object_space() const { return _object_space; }
134 PSMarkSweepDecorator* object_mark_sweep() const { return _object_mark_sweep; }
135 ObjectStartArray* start_array() { return &_start_array; }
136 PSVirtualSpace* virtual_space() const { return _virtual_space;}
137
138 // Has the generation been successfully allocated?
139 bool is_allocated();
140
141 // MarkSweep methods
142 virtual void precompact();
143 void adjust_pointers();
144 void compact();
145
146 // Size info
147 size_t capacity_in_bytes() const { return object_space()->capacity_in_bytes(); }
148 size_t used_in_bytes() const { return object_space()->used_in_bytes(); }
149 size_t free_in_bytes() const { return object_space()->free_in_bytes(); }
150
151 size_t capacity_in_words() const { return object_space()->capacity_in_words(); }
152 size_t used_in_words() const { return object_space()->used_in_words(); }
153 size_t free_in_words() const { return object_space()->free_in_words(); }
154
155 // Includes uncommitted memory
156 size_t contiguous_available() const;
157
158 bool is_maximal_no_gc() const {
159 return virtual_space()->uncommitted_size() == 0;
160 }
161
162 // Calculating new sizes
163 void resize(size_t desired_free_space);
164
165 // Allocation. We report all successful allocations to the size policy
166 // Note that the perm gen does not use this method, and should not!
167 HeapWord* allocate(size_t word_size);
168
169 // Iteration.
170 void oop_iterate_no_header(OopClosure* cl) { object_space()->oop_iterate_no_header(cl); }
171 void object_iterate(ObjectClosure* cl) { object_space()->object_iterate(cl); }
172
173 // Debugging - do not use for time critical operations
174 virtual void print() const;
175 virtual void print_on(outputStream* st) const;
176 void print_used_change(size_t prev_used) const;
177
178 void verify();
179 void verify_object_start_array();
180
181 // These should not used
182 virtual void reset_after_change();
183
184 // These should not used
185 virtual size_t available_for_expansion();
186 virtual size_t available_for_contraction();
187
188 void space_invariants() PRODUCT_RETURN;
189
190 // Performace Counter support
191 void update_counters();
192
193 // Printing support
194 virtual const char* name() const { return _name; }
195
196 // Debugging support
197 // Save the tops of all spaces for later use during mangling.
198 void record_spaces_top() PRODUCT_RETURN;
199 };
200
201 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSOLDGEN_HPP