1 /*
2 * Copyright (c) 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 #include "precompiled.hpp"
26 #include "gc_implementation/concurrentMarkSweep/adaptiveFreeList.hpp"
27 #include "gc_implementation/concurrentMarkSweep/freeChunk.hpp"
28 #include "memory/freeBlockDictionary.hpp"
29 #include "memory/sharedHeap.hpp"
30 #include "runtime/globals.hpp"
31 #include "runtime/mutex.hpp"
32 #include "runtime/vmThread.hpp"
33
34 template <>
35 void AdaptiveFreeList<FreeChunk>::print_on(outputStream* st, const char* c) const {
36 if (c != NULL) {
37 st->print("%16s", c);
38 } else {
39 st->print(SIZE_FORMAT_W(16), size());
40 }
41 st->print("\t"
42 SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t"
43 SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\t" SSIZE_FORMAT_W(14) "\n",
44 bfr_surp(), surplus(), desired(), prev_sweep(), before_sweep(),
45 count(), coal_births(), coal_deaths(), split_births(), split_deaths());
46 }
47
48 template <class Chunk>
49 AdaptiveFreeList<Chunk>::AdaptiveFreeList() : FreeList<Chunk>(), _hint(0) {
50 init_statistics();
51 }
52
53 template <class Chunk>
54 AdaptiveFreeList<Chunk>::AdaptiveFreeList(Chunk* fc) : FreeList<Chunk>(fc), _hint(0) {
55 init_statistics();
56 #ifndef PRODUCT
57 _allocation_stats.set_returned_bytes(size() * HeapWordSize);
58 #endif
59 }
60
61 template <class Chunk>
62 void AdaptiveFreeList<Chunk>::initialize() {
63 FreeList<Chunk>::initialize();
64 set_hint(0);
65 init_statistics(true /* split_birth */);
66 }
67
68 template <class Chunk>
69 void AdaptiveFreeList<Chunk>::reset(size_t hint) {
70 FreeList<Chunk>::reset();
71 set_hint(hint);
72 }
73
74 #ifndef PRODUCT
75 template <class Chunk>
76 void AdaptiveFreeList<Chunk>::assert_proper_lock_protection_work() const {
77 assert(protecting_lock() != NULL, "Don't call this directly");
78 assert(ParallelGCThreads > 0, "Don't call this directly");
79 Thread* thr = Thread::current();
80 if (thr->is_VM_thread() || thr->is_ConcurrentGC_thread()) {
81 // assert that we are holding the freelist lock
82 } else if (thr->is_GC_task_thread()) {
83 assert(protecting_lock()->owned_by_self(), "FreeList RACE DETECTED");
84 } else if (thr->is_Java_thread()) {
85 assert(!SafepointSynchronize::is_at_safepoint(), "Should not be executing");
86 } else {
87 ShouldNotReachHere(); // unaccounted thread type?
88 }
89 }
90 #endif
91 template <class Chunk>
92 void AdaptiveFreeList<Chunk>::init_statistics(bool split_birth) {
93 _allocation_stats.initialize(split_birth);
94 }
95
96 template <class Chunk>
97 size_t AdaptiveFreeList<Chunk>::get_better_size() {
98
99 // A candidate chunk has been found. If it is already under
100 // populated and there is a hinT, REturn the hint(). Else
101 // return the size of this chunk.
102 if (surplus() <= 0) {
103 if (hint() != 0) {
104 return hint();
105 } else {
106 return size();
107 }
108 } else {
109 // This list has a surplus so use it.
110 return size();
111 }
112 }
113
114
115 template <class Chunk>
116 void AdaptiveFreeList<Chunk>::return_chunk_at_head(Chunk* chunk) {
117 assert_proper_lock_protection();
118 return_chunk_at_head(chunk, true);
119 }
120
121 template <class Chunk>
122 void AdaptiveFreeList<Chunk>::return_chunk_at_head(Chunk* chunk, bool record_return) {
123 FreeList<Chunk>::return_chunk_at_head(chunk, record_return);
124 #ifdef ASSERT
125 if (record_return) {
126 increment_returned_bytes_by(size()*HeapWordSize);
127 }
128 #endif
129 }
130
131 template <class Chunk>
132 void AdaptiveFreeList<Chunk>::return_chunk_at_tail(Chunk* chunk) {
133 return_chunk_at_tail(chunk, true);
134 }
135
136 template <class Chunk>
137 void AdaptiveFreeList<Chunk>::return_chunk_at_tail(Chunk* chunk, bool record_return) {
138 FreeList<Chunk>::return_chunk_at_tail(chunk, record_return);
139 #ifdef ASSERT
140 if (record_return) {
141 increment_returned_bytes_by(size()*HeapWordSize);
142 }
143 #endif
144 }
145
146 #ifndef PRODUCT
147 template <class Chunk>
148 void AdaptiveFreeList<Chunk>::verify_stats() const {
149 // The +1 of the LH comparand is to allow some "looseness" in
150 // checking: we usually call this interface when adding a block
151 // and we'll subsequently update the stats; we cannot update the
152 // stats beforehand because in the case of the large-block BT
153 // dictionary for example, this might be the first block and
154 // in that case there would be no place that we could record
155 // the stats (which are kept in the block itself).
156 assert((_allocation_stats.prev_sweep() + _allocation_stats.split_births()
157 + _allocation_stats.coal_births() + 1) // Total Production Stock + 1
158 >= (_allocation_stats.split_deaths() + _allocation_stats.coal_deaths()
159 + (ssize_t)count()), // Total Current Stock + depletion
160 err_msg("FreeList " PTR_FORMAT " of size " SIZE_FORMAT
161 " violates Conservation Principle: "
162 "prev_sweep(" SIZE_FORMAT ")"
163 " + split_births(" SIZE_FORMAT ")"
164 " + coal_births(" SIZE_FORMAT ") + 1 >= "
165 " split_deaths(" SIZE_FORMAT ")"
166 " coal_deaths(" SIZE_FORMAT ")"
167 " + count(" SSIZE_FORMAT ")",
168 this, size(), _allocation_stats.prev_sweep(), _allocation_stats.split_births(),
169 _allocation_stats.split_births(), _allocation_stats.split_deaths(),
170 _allocation_stats.coal_deaths(), count()));
171 }
172 #endif
173
174 // Needs to be after the definitions have been seen.
175 template class AdaptiveFreeList<FreeChunk>;
--- EOF ---