1 /*
2 * Copyright (c) 2012, 2014, 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/orderAccess.inline.hpp"
33 #include "runtime/vmThread.hpp"
34
35 template <>
36 void AdaptiveFreeList<FreeChunk>::print_on(outputStream* st, const char* c) const {
37 if (c != NULL) {
38 st->print("%16s", c);
39 } else {
40 st->print(SIZE_FORMAT_W(16), size());
41 }
42 st->print("\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) "\t"
44 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",
45 bfr_surp(), surplus(), desired(), prev_sweep(), before_sweep(),
46 count(), coal_births(), coal_deaths(), split_births(), split_deaths());
47 }
48
49 template <class Chunk>
50 AdaptiveFreeList<Chunk>::AdaptiveFreeList() : FreeList<Chunk>(), _hint(0) {
51 init_statistics();
52 }
53
54 template <class Chunk>
55 void AdaptiveFreeList<Chunk>::initialize() {
56 FreeList<Chunk>::initialize();
57 set_hint(0);
58 init_statistics(true /* split_birth */);
59 }
60
61 template <class Chunk>
62 void AdaptiveFreeList<Chunk>::reset(size_t hint) {
63 FreeList<Chunk>::reset();
64 set_hint(hint);
65 }
66
67 #ifndef PRODUCT
68 template <class Chunk>
69 void AdaptiveFreeList<Chunk>::assert_proper_lock_protection_work() const {
70 assert(protecting_lock() != NULL, "Don't call this directly");
71 assert(ParallelGCThreads > 0, "Don't call this directly");
72 Thread* thr = Thread::current();
73 if (thr->is_VM_thread() || thr->is_ConcurrentGC_thread()) {
74 // assert that we are holding the freelist lock
75 } else if (thr->is_GC_task_thread()) {
76 assert(protecting_lock()->owned_by_self(), "FreeList RACE DETECTED");
77 } else if (thr->is_Java_thread()) {
78 assert(!SafepointSynchronize::is_at_safepoint(), "Should not be executing");
79 } else {
80 ShouldNotReachHere(); // unaccounted thread type?
81 }
82 }
83 #endif
84 template <class Chunk>
85 void AdaptiveFreeList<Chunk>::init_statistics(bool split_birth) {
86 _allocation_stats.initialize(split_birth);
87 }
88
89 template <class Chunk>
90 size_t AdaptiveFreeList<Chunk>::get_better_size() {
91
92 // A candidate chunk has been found. If it is already under
93 // populated and there is a hinT, REturn the hint(). Else
94 // return the size of this chunk.
95 if (surplus() <= 0) {
96 if (hint() != 0) {
97 return hint();
98 } else {
99 return size();
100 }
101 } else {
102 // This list has a surplus so use it.
103 return size();
104 }
105 }
106
107
108 template <class Chunk>
109 void AdaptiveFreeList<Chunk>::return_chunk_at_head(Chunk* chunk) {
110 assert_proper_lock_protection();
111 return_chunk_at_head(chunk, true);
112 }
113
114 template <class Chunk>
115 void AdaptiveFreeList<Chunk>::return_chunk_at_head(Chunk* chunk, bool record_return) {
116 FreeList<Chunk>::return_chunk_at_head(chunk, record_return);
117 #ifdef ASSERT
118 if (record_return) {
119 increment_returned_bytes_by(size()*HeapWordSize);
120 }
121 #endif
122 }
123
124 template <class Chunk>
125 void AdaptiveFreeList<Chunk>::return_chunk_at_tail(Chunk* chunk) {
126 AdaptiveFreeList<Chunk>::return_chunk_at_tail(chunk, true);
127 }
128
129 template <class Chunk>
130 void AdaptiveFreeList<Chunk>::return_chunk_at_tail(Chunk* chunk, bool record_return) {
131 FreeList<Chunk>::return_chunk_at_tail(chunk, record_return);
132 #ifdef ASSERT
133 if (record_return) {
134 increment_returned_bytes_by(size()*HeapWordSize);
135 }
136 #endif
137 }
138
139 #ifndef PRODUCT
140 template <class Chunk>
141 void AdaptiveFreeList<Chunk>::verify_stats() const {
142 // The +1 of the LH comparand is to allow some "looseness" in
143 // checking: we usually call this interface when adding a block
144 // and we'll subsequently update the stats; we cannot update the
145 // stats beforehand because in the case of the large-block BT
146 // dictionary for example, this might be the first block and
147 // in that case there would be no place that we could record
148 // the stats (which are kept in the block itself).
149 assert((_allocation_stats.prev_sweep() + _allocation_stats.split_births()
150 + _allocation_stats.coal_births() + 1) // Total Production Stock + 1
151 >= (_allocation_stats.split_deaths() + _allocation_stats.coal_deaths()
152 + (ssize_t)count()), // Total Current Stock + depletion
153 err_msg("FreeList " PTR_FORMAT " of size " SIZE_FORMAT
154 " violates Conservation Principle: "
155 "prev_sweep(" SIZE_FORMAT ")"
156 " + split_births(" SIZE_FORMAT ")"
157 " + coal_births(" SIZE_FORMAT ") + 1 >= "
158 " split_deaths(" SIZE_FORMAT ")"
159 " coal_deaths(" SIZE_FORMAT ")"
160 " + count(" SSIZE_FORMAT ")",
161 p2i(this), size(), _allocation_stats.prev_sweep(), _allocation_stats.split_births(),
162 _allocation_stats.coal_births(), _allocation_stats.split_deaths(),
163 _allocation_stats.coal_deaths(), count()));
164 }
165 #endif
166
167 // Needs to be after the definitions have been seen.
168 template class AdaptiveFreeList<FreeChunk>;