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_CMS_ADAPTIVEFREELIST_HPP
26 #define SHARE_VM_GC_CMS_ADAPTIVEFREELIST_HPP
27
28 #include "gc/shared/allocationStats.hpp"
29 #include "memory/freeList.hpp"
30
31 class CompactibleFreeListSpace;
32
33 // A class for maintaining a free list of Chunk's. The FreeList
34 // maintains a the structure of the list (head, tail, etc.) plus
35 // statistics for allocations from the list. The links between items
36 // are not part of FreeList. The statistics are
37 // used to make decisions about coalescing Chunk's when they
38 // are swept during collection.
39 //
40 // See the corresponding .cpp file for a description of the specifics
41 // for that implementation.
42
43 class Mutex;
44
45 template <class Chunk>
46 class AdaptiveFreeList : public FreeList<Chunk> {
47 friend class CompactibleFreeListSpace;
48 friend class VMStructs;
49 // friend class PrintTreeCensusClosure<Chunk, FreeList_t>;
50
51 size_t _hint; // next larger size list with a positive surplus
52
53 AllocationStats _allocation_stats; // allocation-related statistics
54
55 public:
56
57 AdaptiveFreeList();
58
59 using FreeList<Chunk>::assert_proper_lock_protection;
60 #ifdef ASSERT
61 using FreeList<Chunk>::protecting_lock;
62 #endif
63 using FreeList<Chunk>::count;
64 using FreeList<Chunk>::size;
65 using FreeList<Chunk>::verify_chunk_in_free_list;
66 using FreeList<Chunk>::getFirstNChunksFromList;
67 using FreeList<Chunk>::print_on;
68 void return_chunk_at_head(Chunk* fc, bool record_return);
69 void return_chunk_at_head(Chunk* fc);
70 void return_chunk_at_tail(Chunk* fc, bool record_return);
71 void return_chunk_at_tail(Chunk* fc);
72 using FreeList<Chunk>::return_chunk_at_tail;
73 using FreeList<Chunk>::remove_chunk;
74 using FreeList<Chunk>::prepend;
75 using FreeList<Chunk>::print_labels_on;
76 using FreeList<Chunk>::get_chunk_at_head;
77
78 // Initialize.
79 void initialize();
80
81 // Reset the head, tail, hint, and count of a free list.
82 void reset(size_t hint);
83
84 void print_on(outputStream* st, const char* c = NULL) const;
85
86 size_t hint() const {
87 return _hint;
88 }
89 void set_hint(size_t v) {
90 assert_proper_lock_protection();
91 assert(v == 0 || size() < v, "Bad hint");
92 _hint = v;
93 }
94
95 size_t get_better_size();
96
97 // Accessors for statistics
98 void init_statistics(bool split_birth = false);
99
100 AllocationStats* allocation_stats() {
101 assert_proper_lock_protection();
102 return &_allocation_stats;
103 }
104
105 ssize_t desired() const {
106 return _allocation_stats.desired();
107 }
108 void set_desired(ssize_t v) {
109 assert_proper_lock_protection();
110 _allocation_stats.set_desired(v);
111 }
112 void compute_desired(float inter_sweep_current,
113 float inter_sweep_estimate,
114 float intra_sweep_estimate) {
115 assert_proper_lock_protection();
116 _allocation_stats.compute_desired(count(),
117 inter_sweep_current,
118 inter_sweep_estimate,
119 intra_sweep_estimate);
120 }
121 ssize_t coal_desired() const {
122 return _allocation_stats.coal_desired();
123 }
124 void set_coal_desired(ssize_t v) {
125 assert_proper_lock_protection();
126 _allocation_stats.set_coal_desired(v);
127 }
128
129 ssize_t surplus() const {
130 return _allocation_stats.surplus();
131 }
132 void set_surplus(ssize_t v) {
133 assert_proper_lock_protection();
134 _allocation_stats.set_surplus(v);
135 }
136 void increment_surplus() {
137 assert_proper_lock_protection();
138 _allocation_stats.increment_surplus();
139 }
140 void decrement_surplus() {
141 assert_proper_lock_protection();
142 _allocation_stats.decrement_surplus();
143 }
144
145 ssize_t bfr_surp() const {
146 return _allocation_stats.bfr_surp();
147 }
148 void set_bfr_surp(ssize_t v) {
149 assert_proper_lock_protection();
150 _allocation_stats.set_bfr_surp(v);
151 }
152 ssize_t prev_sweep() const {
153 return _allocation_stats.prev_sweep();
154 }
155 void set_prev_sweep(ssize_t v) {
156 assert_proper_lock_protection();
157 _allocation_stats.set_prev_sweep(v);
158 }
159 ssize_t before_sweep() const {
160 return _allocation_stats.before_sweep();
161 }
162 void set_before_sweep(ssize_t v) {
163 assert_proper_lock_protection();
164 _allocation_stats.set_before_sweep(v);
165 }
166
167 ssize_t coal_births() const {
168 return _allocation_stats.coal_births();
169 }
170 void set_coal_births(ssize_t v) {
171 assert_proper_lock_protection();
172 _allocation_stats.set_coal_births(v);
173 }
174 void increment_coal_births() {
175 assert_proper_lock_protection();
176 _allocation_stats.increment_coal_births();
177 }
178
179 ssize_t coal_deaths() const {
180 return _allocation_stats.coal_deaths();
181 }
182 void set_coal_deaths(ssize_t v) {
183 assert_proper_lock_protection();
184 _allocation_stats.set_coal_deaths(v);
185 }
186 void increment_coal_deaths() {
187 assert_proper_lock_protection();
188 _allocation_stats.increment_coal_deaths();
189 }
190
191 ssize_t split_births() const {
192 return _allocation_stats.split_births();
193 }
194 void set_split_births(ssize_t v) {
195 assert_proper_lock_protection();
196 _allocation_stats.set_split_births(v);
197 }
198 void increment_split_births() {
199 assert_proper_lock_protection();
200 _allocation_stats.increment_split_births();
201 }
202
203 ssize_t split_deaths() const {
204 return _allocation_stats.split_deaths();
205 }
206 void set_split_deaths(ssize_t v) {
207 assert_proper_lock_protection();
208 _allocation_stats.set_split_deaths(v);
209 }
210 void increment_split_deaths() {
211 assert_proper_lock_protection();
212 _allocation_stats.increment_split_deaths();
213 }
214
215 #ifndef PRODUCT
216 // For debugging. The "_returned_bytes" in all the lists are summed
217 // and compared with the total number of bytes swept during a
218 // collection.
219 size_t returned_bytes() const { return _allocation_stats.returned_bytes(); }
220 void set_returned_bytes(size_t v) { _allocation_stats.set_returned_bytes(v); }
221 void increment_returned_bytes_by(size_t v) {
222 _allocation_stats.set_returned_bytes(_allocation_stats.returned_bytes() + v);
223 }
224 // Stats verification
225 void verify_stats() const;
226 #endif // NOT PRODUCT
227 };
228
229 #endif // SHARE_VM_GC_CMS_ADAPTIVEFREELIST_HPP