annotate src/share/vm/gc_implementation/g1/concurrentG1Refine.hpp @ 1472:c18cbe5936b8

6941466: Oracle rebranding changes for Hotspot repositories Summary: Change all the Sun copyrights to Oracle copyright Reviewed-by: ohair
author trims
date Thu, 27 May 2010 19:08:38 -0700
parents b81f3572f355
children 2d160770d2e5
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ysr@342 1 /*
trims@1472 2 * Copyright (c) 2001, 2009, Oracle and/or its affiliates. All rights reserved.
ysr@342 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ysr@342 4 *
ysr@342 5 * This code is free software; you can redistribute it and/or modify it
ysr@342 6 * under the terms of the GNU General Public License version 2 only, as
ysr@342 7 * published by the Free Software Foundation.
ysr@342 8 *
ysr@342 9 * This code is distributed in the hope that it will be useful, but WITHOUT
ysr@342 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ysr@342 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
ysr@342 12 * version 2 for more details (a copy is included in the LICENSE file that
ysr@342 13 * accompanied this code).
ysr@342 14 *
ysr@342 15 * You should have received a copy of the GNU General Public License version
ysr@342 16 * 2 along with this work; if not, write to the Free Software Foundation,
ysr@342 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ysr@342 18 *
trims@1472 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1472 20 * or visit www.oracle.com if you need additional information or have any
trims@1472 21 * questions.
ysr@342 22 *
ysr@342 23 */
ysr@342 24
ysr@342 25 // Forward decl
ysr@342 26 class ConcurrentG1RefineThread;
ysr@342 27 class G1RemSet;
ysr@342 28
apetrusenko@549 29 class ConcurrentG1Refine: public CHeapObj {
iveresov@794 30 ConcurrentG1RefineThread** _threads;
iveresov@794 31 int _n_threads;
iveresov@1111 32 int _n_worker_threads;
iveresov@1111 33 /*
iveresov@1111 34 * The value of the update buffer queue length falls into one of 3 zones:
iveresov@1111 35 * green, yellow, red. If the value is in [0, green) nothing is
iveresov@1111 36 * done, the buffers are left unprocessed to enable the caching effect of the
iveresov@1111 37 * dirtied cards. In the yellow zone [green, yellow) the concurrent refinement
iveresov@1111 38 * threads are gradually activated. In [yellow, red) all threads are
iveresov@1111 39 * running. If the length becomes red (max queue length) the mutators start
iveresov@1111 40 * processing the buffers.
iveresov@1111 41 *
tonyp@1282 42 * There are some interesting cases (when G1UseAdaptiveConcRefinement
tonyp@1282 43 * is turned off):
iveresov@1111 44 * 1) green = yellow = red = 0. In this case the mutator will process all
iveresov@1111 45 * buffers. Except for those that are created by the deferred updates
iveresov@1111 46 * machinery during a collection.
iveresov@1111 47 * 2) green = 0. Means no caching. Can be a good way to minimize the
iveresov@1111 48 * amount of time spent updating rsets during a collection.
iveresov@1111 49 */
iveresov@1111 50 int _green_zone;
iveresov@1111 51 int _yellow_zone;
iveresov@1111 52 int _red_zone;
iveresov@1111 53
iveresov@1111 54 int _thread_threshold_step;
iveresov@1111 55
iveresov@1111 56 // Reset the threshold step value based of the current zone boundaries.
iveresov@1111 57 void reset_threshold_step();
johnc@890 58
ysr@342 59 // The cache for card refinement.
johnc@890 60 bool _use_cache;
johnc@890 61 bool _def_use_cache;
ysr@342 62
johnc@890 63 size_t _n_periods; // Used as clearing epoch
johnc@890 64
johnc@890 65 // An evicting cache of the number of times each card
johnc@890 66 // is accessed. Reduces, but does not eliminate, the amount
johnc@890 67 // of duplicated processing of dirty cards.
johnc@890 68
johnc@890 69 enum SomePrivateConstants {
johnc@890 70 epoch_bits = 32,
johnc@890 71 card_num_shift = epoch_bits,
johnc@890 72 epoch_mask = AllBits,
johnc@890 73 card_num_mask = AllBits,
johnc@890 74
johnc@890 75 // The initial cache size is approximately this fraction
johnc@890 76 // of a maximal cache (i.e. the size needed for all cards
johnc@890 77 // in the heap)
johnc@890 78 InitialCacheFraction = 512
johnc@890 79 };
johnc@890 80
johnc@890 81 const static julong card_num_mask_in_place =
johnc@890 82 (julong) card_num_mask << card_num_shift;
johnc@890 83
johnc@890 84 typedef struct {
johnc@890 85 julong _value; // | card_num | epoch |
johnc@890 86 } CardEpochCacheEntry;
johnc@890 87
johnc@890 88 julong make_epoch_entry(unsigned int card_num, unsigned int epoch) {
johnc@890 89 assert(0 <= card_num && card_num < _max_n_card_counts, "Bounds");
johnc@890 90 assert(0 <= epoch && epoch <= _n_periods, "must be");
johnc@890 91
johnc@890 92 return ((julong) card_num << card_num_shift) | epoch;
johnc@890 93 }
johnc@890 94
johnc@890 95 unsigned int extract_epoch(julong v) {
johnc@890 96 return (v & epoch_mask);
johnc@890 97 }
johnc@890 98
johnc@890 99 unsigned int extract_card_num(julong v) {
johnc@890 100 return (v & card_num_mask_in_place) >> card_num_shift;
johnc@890 101 }
johnc@890 102
johnc@890 103 typedef struct {
johnc@890 104 unsigned char _count;
johnc@890 105 unsigned char _evict_count;
johnc@890 106 } CardCountCacheEntry;
johnc@890 107
johnc@890 108 CardCountCacheEntry* _card_counts;
johnc@890 109 CardEpochCacheEntry* _card_epochs;
johnc@890 110
johnc@890 111 // The current number of buckets in the card count cache
johnc@890 112 unsigned _n_card_counts;
johnc@890 113
johnc@890 114 // The max number of buckets required for the number of
johnc@890 115 // cards for the entire reserved heap
johnc@890 116 unsigned _max_n_card_counts;
johnc@890 117
johnc@890 118 // Possible sizes of the cache: odd primes that roughly double in size.
johnc@890 119 // (See jvmtiTagMap.cpp).
johnc@890 120 static int _cc_cache_sizes[];
johnc@890 121
johnc@890 122 // The index in _cc_cache_sizes corresponding to the size of
johnc@890 123 // _card_counts.
johnc@890 124 int _cache_size_index;
johnc@890 125
johnc@890 126 bool _expand_card_counts;
johnc@890 127
johnc@890 128 const jbyte* _ct_bot;
johnc@889 129
johnc@889 130 jbyte** _hot_cache;
johnc@889 131 int _hot_cache_size;
johnc@889 132 int _n_hot;
johnc@889 133 int _hot_cache_idx;
johnc@889 134
johnc@889 135 int _hot_cache_par_chunk_size;
johnc@889 136 volatile int _hot_cache_par_claimed_idx;
ysr@342 137
johnc@890 138 // Needed to workaround 6817995
johnc@890 139 CardTableModRefBS* _ct_bs;
johnc@890 140 G1CollectedHeap* _g1h;
johnc@890 141
johnc@890 142 // Expands the array that holds the card counts to the next size up
johnc@890 143 void expand_card_count_cache();
johnc@890 144
johnc@890 145 // hash a given key (index of card_ptr) with the specified size
johnc@890 146 static unsigned int hash(size_t key, int size) {
johnc@890 147 return (unsigned int) key % size;
johnc@890 148 }
johnc@890 149
johnc@890 150 // hash a given key (index of card_ptr)
johnc@890 151 unsigned int hash(size_t key) {
johnc@890 152 return hash(key, _n_card_counts);
johnc@890 153 }
johnc@890 154
johnc@890 155 unsigned ptr_2_card_num(jbyte* card_ptr) {
johnc@890 156 return (unsigned) (card_ptr - _ct_bot);
johnc@890 157 }
johnc@890 158
johnc@890 159 jbyte* card_num_2_ptr(unsigned card_num) {
johnc@890 160 return (jbyte*) (_ct_bot + card_num);
johnc@890 161 }
johnc@890 162
ysr@342 163 // Returns the count of this card after incrementing it.
johnc@890 164 jbyte* add_card_count(jbyte* card_ptr, int* count, bool* defer);
ysr@342 165
johnc@890 166 // Returns true if this card is in a young region
johnc@890 167 bool is_young_card(jbyte* card_ptr);
johnc@890 168
ysr@342 169 public:
ysr@342 170 ConcurrentG1Refine();
ysr@342 171 ~ConcurrentG1Refine();
ysr@342 172
ysr@342 173 void init(); // Accomplish some initialization that has to wait.
iveresov@794 174 void stop();
ysr@342 175
iveresov@1111 176 void reinitialize_threads();
iveresov@1111 177
iveresov@794 178 // Iterate over the conc refine threads
iveresov@794 179 void threads_do(ThreadClosure *tc);
ysr@342 180
ysr@342 181 // If this is the first entry for the slot, writes into the cache and
ysr@342 182 // returns NULL. If it causes an eviction, returns the evicted pointer.
ysr@342 183 // Otherwise, its a cache hit, and returns NULL.
johnc@890 184 jbyte* cache_insert(jbyte* card_ptr, bool* defer);
ysr@342 185
ysr@342 186 // Process the cached entries.
ysr@342 187 void clean_up_cache(int worker_i, G1RemSet* g1rs);
ysr@342 188
johnc@889 189 // Set up for parallel processing of the cards in the hot cache
johnc@889 190 void clear_hot_cache_claimed_index() {
johnc@889 191 _hot_cache_par_claimed_idx = 0;
johnc@889 192 }
johnc@889 193
ysr@342 194 // Discard entries in the hot cache.
ysr@342 195 void clear_hot_cache() {
ysr@342 196 _hot_cache_idx = 0; _n_hot = 0;
ysr@342 197 }
ysr@342 198
ysr@342 199 bool hot_cache_is_empty() { return _n_hot == 0; }
ysr@342 200
ysr@342 201 bool use_cache() { return _use_cache; }
ysr@342 202 void set_use_cache(bool b) {
ysr@342 203 if (b) _use_cache = _def_use_cache;
ysr@342 204 else _use_cache = false;
ysr@342 205 }
ysr@342 206
ysr@342 207 void clear_and_record_card_counts();
iveresov@795 208
iveresov@1111 209 static int thread_num();
tonyp@1019 210
tonyp@1019 211 void print_worker_threads_on(outputStream* st) const;
iveresov@1111 212
iveresov@1111 213 void set_green_zone(int x) { _green_zone = x; }
iveresov@1111 214 void set_yellow_zone(int x) { _yellow_zone = x; }
iveresov@1111 215 void set_red_zone(int x) { _red_zone = x; }
iveresov@1111 216
iveresov@1111 217 int green_zone() const { return _green_zone; }
iveresov@1111 218 int yellow_zone() const { return _yellow_zone; }
iveresov@1111 219 int red_zone() const { return _red_zone; }
iveresov@1111 220
iveresov@1111 221 int total_thread_num() const { return _n_threads; }
iveresov@1111 222 int worker_thread_num() const { return _n_worker_threads; }
iveresov@1111 223
iveresov@1111 224 int thread_threshold_step() const { return _thread_threshold_step; }
ysr@342 225 };