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 void AdaptiveFreeList<Chunk>::initialize() {
55 FreeList<Chunk>::initialize();
56 set_hint(0);
57 init_statistics(true /* split_birth */);
58 }
59
60 template <class Chunk>
61 void AdaptiveFreeList<Chunk>::reset(size_t hint) {
62 FreeList<Chunk>::reset();
63 set_hint(hint);
64 }
65
66 #ifndef PRODUCT
67 template <class Chunk>
68 void AdaptiveFreeList<Chunk>::assert_proper_lock_protection_work() const {
69 assert(protecting_lock() != NULL, "Don't call this directly");
70 assert(ParallelGCThreads > 0, "Don't call this directly");
71 Thread* thr = Thread::current();
72 if (thr->is_VM_thread() || thr->is_ConcurrentGC_thread()) {
73 // assert that we are holding the freelist lock
74 } else if (thr->is_GC_task_thread()) {
75 assert(protecting_lock()->owned_by_self(), "FreeList RACE DETECTED");
76 } else if (thr->is_Java_thread()) {
77 assert(!SafepointSynchronize::is_at_safepoint(), "Should not be executing");
78 } else {
79 ShouldNotReachHere(); // unaccounted thread type?
80 }
81 }
82 #endif
83 template <class Chunk>
84 void AdaptiveFreeList<Chunk>::init_statistics(bool split_birth) {
85 _allocation_stats.initialize(split_birth);
86 }
87
88 template <class Chunk>
89 size_t AdaptiveFreeList<Chunk>::get_better_size() {
90
91 // A candidate chunk has been found. If it is already under
92 // populated and there is a hinT, REturn the hint(). Else
93 // return the size of this chunk.
94 if (surplus() <= 0) {
95 if (hint() != 0) {
96 return hint();
97 } else {
98 return size();
99 }
100 } else {
101 // This list has a surplus so use it.
102 return size();
103 }
104 }
105
106
107 template <class Chunk>
108 void AdaptiveFreeList<Chunk>::return_chunk_at_head(Chunk* chunk) {
109 assert_proper_lock_protection();
110 return_chunk_at_head(chunk, true);
111 }
112
113 template <class Chunk>
114 void AdaptiveFreeList<Chunk>::return_chunk_at_head(Chunk* chunk, bool record_return) {
115 FreeList<Chunk>::return_chunk_at_head(chunk, record_return);
116 #ifdef ASSERT
117 if (record_return) {
118 increment_returned_bytes_by(size()*HeapWordSize);
119 }
120 #endif
121 }
122
123 template <class Chunk>
124 void AdaptiveFreeList<Chunk>::return_chunk_at_tail(Chunk* chunk) {
125 return_chunk_at_tail(chunk, true);
126 }
127
128 template <class Chunk>
129 void AdaptiveFreeList<Chunk>::return_chunk_at_tail(Chunk* chunk, bool record_return) {
130 FreeList<Chunk>::return_chunk_at_tail(chunk, record_return);
131 #ifdef ASSERT
132 if (record_return) {
133 increment_returned_bytes_by(size()*HeapWordSize);
134 }
135 #endif
136 }
137
138 #ifndef PRODUCT
139 template <class Chunk>
140 void AdaptiveFreeList<Chunk>::verify_stats() const {
141 // The +1 of the LH comparand is to allow some "looseness" in
142 // checking: we usually call this interface when adding a block
143 // and we'll subsequently update the stats; we cannot update the
144 // stats beforehand because in the case of the large-block BT
145 // dictionary for example, this might be the first block and
146 // in that case there would be no place that we could record
147 // the stats (which are kept in the block itself).
148 assert((_allocation_stats.prev_sweep() + _allocation_stats.split_births()
149 + _allocation_stats.coal_births() + 1) // Total Production Stock + 1
150 >= (_allocation_stats.split_deaths() + _allocation_stats.coal_deaths()
151 + (ssize_t)count()), // Total Current Stock + depletion
152 err_msg("FreeList " PTR_FORMAT " of size " SIZE_FORMAT
153 " violates Conservation Principle: "
154 "prev_sweep(" SIZE_FORMAT ")"
155 " + split_births(" SIZE_FORMAT ")"
156 " + coal_births(" SIZE_FORMAT ") + 1 >= "
157 " split_deaths(" SIZE_FORMAT ")"
158 " coal_deaths(" SIZE_FORMAT ")"
159 " + count(" SSIZE_FORMAT ")",
160 this, size(), _allocation_stats.prev_sweep(), _allocation_stats.split_births(),
161 _allocation_stats.split_births(), _allocation_stats.split_deaths(),
162 _allocation_stats.coal_deaths(), count()));
163 }
164 #endif
165
166 // Needs to be after the definitions have been seen.
167 template class AdaptiveFreeList<FreeChunk>;