1 /*
2 * Copyright (c) 2001, 2010, 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 *
77 enum SomePrivateConstants {
78 epoch_bits = 32,
79 card_num_shift = epoch_bits,
80 epoch_mask = AllBits,
81 card_num_mask = AllBits,
82
83 // The initial cache size is approximately this fraction
84 // of a maximal cache (i.e. the size needed for all cards
85 // in the heap)
86 InitialCacheFraction = 512
87 };
88
89 const static julong card_num_mask_in_place =
90 (julong) card_num_mask << card_num_shift;
91
92 typedef struct {
93 julong _value; // | card_num | epoch |
94 } CardEpochCacheEntry;
95
96 julong make_epoch_entry(unsigned int card_num, unsigned int epoch) {
97 assert(0 <= card_num && card_num < _max_n_card_counts, "Bounds");
98 assert(0 <= epoch && epoch <= _n_periods, "must be");
99
100 return ((julong) card_num << card_num_shift) | epoch;
101 }
102
103 unsigned int extract_epoch(julong v) {
104 return (v & epoch_mask);
105 }
106
107 unsigned int extract_card_num(julong v) {
108 return (v & card_num_mask_in_place) >> card_num_shift;
109 }
110
111 typedef struct {
112 unsigned char _count;
113 unsigned char _evict_count;
114 } CardCountCacheEntry;
115
116 CardCountCacheEntry* _card_counts;
117 CardEpochCacheEntry* _card_epochs;
118
119 // The current number of buckets in the card count cache
120 unsigned _n_card_counts;
121
122 // The max number of buckets required for the number of
123 // cards for the entire reserved heap
124 unsigned _max_n_card_counts;
125
126 // Possible sizes of the cache: odd primes that roughly double in size.
127 // (See jvmtiTagMap.cpp).
128 static int _cc_cache_sizes[];
129
130 // The index in _cc_cache_sizes corresponding to the size of
131 // _card_counts.
132 int _cache_size_index;
133
134 bool _expand_card_counts;
135
136 const jbyte* _ct_bot;
137
138 jbyte** _hot_cache;
139 int _hot_cache_size;
140 int _n_hot;
141 int _hot_cache_idx;
142
143 int _hot_cache_par_chunk_size;
144 volatile int _hot_cache_par_claimed_idx;
145
146 // Needed to workaround 6817995
147 CardTableModRefBS* _ct_bs;
148 G1CollectedHeap* _g1h;
149
150 // Expands the array that holds the card counts to the next size up
151 void expand_card_count_cache();
152
153 // hash a given key (index of card_ptr) with the specified size
154 static unsigned int hash(size_t key, int size) {
155 return (unsigned int) key % size;
156 }
157
158 // hash a given key (index of card_ptr)
159 unsigned int hash(size_t key) {
160 return hash(key, _n_card_counts);
161 }
162
163 unsigned ptr_2_card_num(jbyte* card_ptr) {
164 return (unsigned) (card_ptr - _ct_bot);
165 }
166
167 jbyte* card_num_2_ptr(unsigned card_num) {
168 return (jbyte*) (_ct_bot + card_num);
169 }
170
171 // Returns the count of this card after incrementing it.
|
1 /*
2 * Copyright (c) 2001, 2011, 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 *
77 enum SomePrivateConstants {
78 epoch_bits = 32,
79 card_num_shift = epoch_bits,
80 epoch_mask = AllBits,
81 card_num_mask = AllBits,
82
83 // The initial cache size is approximately this fraction
84 // of a maximal cache (i.e. the size needed for all cards
85 // in the heap)
86 InitialCacheFraction = 512
87 };
88
89 const static julong card_num_mask_in_place =
90 (julong) card_num_mask << card_num_shift;
91
92 typedef struct {
93 julong _value; // | card_num | epoch |
94 } CardEpochCacheEntry;
95
96 julong make_epoch_entry(unsigned int card_num, unsigned int epoch) {
97 assert(0 <= card_num && card_num < _max_cards, "Bounds");
98 assert(0 <= epoch && epoch <= _n_periods, "must be");
99
100 return ((julong) card_num << card_num_shift) | epoch;
101 }
102
103 unsigned int extract_epoch(julong v) {
104 return (v & epoch_mask);
105 }
106
107 unsigned int extract_card_num(julong v) {
108 return (v & card_num_mask_in_place) >> card_num_shift;
109 }
110
111 typedef struct {
112 unsigned char _count;
113 unsigned char _evict_count;
114 } CardCountCacheEntry;
115
116 CardCountCacheEntry* _card_counts;
117 CardEpochCacheEntry* _card_epochs;
118
119 // The current number of buckets in the card count cache
120 unsigned _n_card_counts;
121
122 // The number of cards for the entire reserved heap
123 unsigned _max_cards;
124
125 // The max number of buckets for the card counts and epochs caches.
126 // This is the maximum that the counts and epochs will grow to.
127 // It is specified as a fraction or percentage of _max_cards using
128 // G1MaxHotCardCountSizePercent (currently 50%).
129 unsigned _max_n_card_counts;
130
131 // Possible sizes of the cache: odd primes that roughly double in size.
132 // (See jvmtiTagMap.cpp).
133 enum {
134 MAX_CC_CACHE_INDEX = 15 // maximum index into the cache size array.
135 };
136
137 static int _cc_cache_sizes[MAX_CC_CACHE_INDEX];
138
139 // The index in _cc_cache_sizes corresponding to the size of
140 // _card_counts.
141 int _cache_size_index;
142
143 bool _expand_card_counts;
144
145 const jbyte* _ct_bot;
146
147 jbyte** _hot_cache;
148 int _hot_cache_size;
149 int _n_hot;
150 int _hot_cache_idx;
151
152 int _hot_cache_par_chunk_size;
153 volatile int _hot_cache_par_claimed_idx;
154
155 // Needed to workaround 6817995
156 CardTableModRefBS* _ct_bs;
157 G1CollectedHeap* _g1h;
158
159 // Helper routine for expand_card_count_cache().
160 // The arrays used to hold the card counts and the epochs must have
161 // a 1:1 correspondence. Hence they are allocated and freed together.
162 // Returns true if the allocations of both the counts and epochs
163 // were successful; false otherwise.
164 bool allocate_card_count_cache(int n, CardCountCacheEntry** counts,
165 CardEpochCacheEntry** epochs);
166
167 // Expands the arrays that hold the card counts and epochs
168 // to the cache size at index. Returns true if the expansion/
169 // allocation was successful; false otherwise.
170 bool expand_card_count_cache(int index);
171
172 // hash a given key (index of card_ptr) with the specified size
173 static unsigned int hash(size_t key, int size) {
174 return (unsigned int) key % size;
175 }
176
177 // hash a given key (index of card_ptr)
178 unsigned int hash(size_t key) {
179 return hash(key, _n_card_counts);
180 }
181
182 unsigned ptr_2_card_num(jbyte* card_ptr) {
183 return (unsigned) (card_ptr - _ct_bot);
184 }
185
186 jbyte* card_num_2_ptr(unsigned card_num) {
187 return (jbyte*) (_ct_bot + card_num);
188 }
189
190 // Returns the count of this card after incrementing it.
|