1/*
2 * Copyright (c) 2018, 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#include "precompiled.hpp"
25
26#include "logging/log.hpp"
27#include "memory/binaryTreeDictionary.inline.hpp"
28#include "memory/metaspace/blockFreelist.hpp"
29#include "utilities/ostream.hpp"
30#include "utilities/globalDefinitions.hpp"
31
32
33namespace metaspace {
34
35
36BlockFreelist::BlockFreelist() : _dictionary(new BlockTreeDictionary()), _small_blocks(NULL) {}
37
38BlockFreelist::~BlockFreelist() {
39 delete _dictionary;
40 if (_small_blocks != NULL) {
41 delete _small_blocks;
42 }
43}
44
45void BlockFreelist::return_block(MetaWord* p, size_t word_size) {
46 assert(word_size >= SmallBlocks::small_block_min_size(), "never return dark matter");
47
48 Metablock* free_chunk = ::new (p) Metablock(word_size);
49 if (word_size < SmallBlocks::small_block_max_size()) {
50 small_blocks()->return_block(free_chunk, word_size);
51 } else {
52 dictionary()->return_chunk(free_chunk);
53}
54 log_trace(gc, metaspace, freelist, blocks)("returning block at " INTPTR_FORMAT " size = "
55 SIZE_FORMAT, p2i(free_chunk), word_size);
56}
57
58MetaWord* BlockFreelist::get_block(size_t word_size) {
59 assert(word_size >= SmallBlocks::small_block_min_size(), "never get dark matter");
60
61 // Try small_blocks first.
62 if (word_size < SmallBlocks::small_block_max_size()) {
63 // Don't create small_blocks() until needed. small_blocks() allocates the small block list for
64 // this space manager.
65 MetaWord* new_block = (MetaWord*) small_blocks()->get_block(word_size);
66 if (new_block != NULL) {
67 log_trace(gc, metaspace, freelist, blocks)("getting block at " INTPTR_FORMAT " size = " SIZE_FORMAT,
68 p2i(new_block), word_size);
69 return new_block;
70 }
71 }
72
73 if (word_size < BlockFreelist::min_dictionary_size()) {
74 // If allocation in small blocks fails, this is Dark Matter. Too small for dictionary.
75 return NULL;
76 }
77
78 Metablock* free_block = dictionary()->get_chunk(word_size);
79 if (free_block == NULL) {
80 return NULL;
81 }
82
83 const size_t block_size = free_block->size();
84 if (block_size > WasteMultiplier * word_size) {
85 return_block((MetaWord*)free_block, block_size);
86 return NULL;
87 }
88
89 MetaWord* new_block = (MetaWord*)free_block;
90 assert(block_size >= word_size, "Incorrect size of block from freelist");
91 const size_t unused = block_size - word_size;
92 if (unused >= SmallBlocks::small_block_min_size()) {
93 return_block(new_block + word_size, unused);
94 }
95
96 log_trace(gc, metaspace, freelist, blocks)("getting block at " INTPTR_FORMAT " size = " SIZE_FORMAT,
97 p2i(new_block), word_size);
98 return new_block;
99}
100
101void BlockFreelist::print_on(outputStream* st) const {
102 dictionary()->print_free_lists(st);
103 if (_small_blocks != NULL) {
104 _small_blocks->print_on(st);
105 }
106}
107
108} // namespace metaspace
109
110