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/cms/allocationStats.hpp"
29#include "memory/freeList.hpp"
30
31class 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
43class Mutex;
44
45template <class Chunk>
46class 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
230