ysr@777: /*
xdono@1014:  * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
ysr@777:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ysr@777:  *
ysr@777:  * This code is free software; you can redistribute it and/or modify it
ysr@777:  * under the terms of the GNU General Public License version 2 only, as
ysr@777:  * published by the Free Software Foundation.
ysr@777:  *
ysr@777:  * This code is distributed in the hope that it will be useful, but WITHOUT
ysr@777:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ysr@777:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
ysr@777:  * version 2 for more details (a copy is included in the LICENSE file that
ysr@777:  * accompanied this code).
ysr@777:  *
ysr@777:  * You should have received a copy of the GNU General Public License version
ysr@777:  * 2 along with this work; if not, write to the Free Software Foundation,
ysr@777:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ysr@777:  *
ysr@777:  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
ysr@777:  * CA 95054 USA or visit www.sun.com if you need additional information or
ysr@777:  * have any questions.
ysr@777:  *
ysr@777:  */
ysr@777: 
ysr@777: // Forward decl
ysr@777: class ConcurrentG1RefineThread;
ysr@777: class G1RemSet;
ysr@777: 
apetrusenko@984: class ConcurrentG1Refine: public CHeapObj {
iveresov@1229:   ConcurrentG1RefineThread** _threads;
iveresov@1229:   int _n_threads;
johnc@1325: 
ysr@777:   // The cache for card refinement.
johnc@1325:   bool   _use_cache;
johnc@1325:   bool   _def_use_cache;
ysr@777: 
johnc@1325:   size_t _n_periods;    // Used as clearing epoch
johnc@1325: 
johnc@1325:   // An evicting cache of the number of times each card
johnc@1325:   // is accessed. Reduces, but does not eliminate, the amount
johnc@1325:   // of duplicated processing of dirty cards.
johnc@1325: 
johnc@1325:   enum SomePrivateConstants {
johnc@1325:     epoch_bits           = 32,
johnc@1325:     card_num_shift       = epoch_bits,
johnc@1325:     epoch_mask           = AllBits,
johnc@1325:     card_num_mask        = AllBits,
johnc@1325: 
johnc@1325:     // The initial cache size is approximately this fraction
johnc@1325:     // of a maximal cache (i.e. the size needed for all cards
johnc@1325:     // in the heap)
johnc@1325:     InitialCacheFraction = 512
johnc@1325:   };
johnc@1325: 
johnc@1325:   const static julong card_num_mask_in_place =
johnc@1325:                         (julong) card_num_mask << card_num_shift;
johnc@1325: 
johnc@1325:   typedef struct {
johnc@1325:     julong _value;      // |  card_num   |  epoch   |
johnc@1325:   } CardEpochCacheEntry;
johnc@1325: 
johnc@1325:   julong make_epoch_entry(unsigned int card_num, unsigned int epoch) {
johnc@1325:     assert(0 <= card_num && card_num < _max_n_card_counts, "Bounds");
johnc@1325:     assert(0 <= epoch && epoch <= _n_periods, "must be");
johnc@1325: 
johnc@1325:     return ((julong) card_num << card_num_shift) | epoch;
johnc@1325:   }
johnc@1325: 
johnc@1325:   unsigned int extract_epoch(julong v) {
johnc@1325:     return (v & epoch_mask);
johnc@1325:   }
johnc@1325: 
johnc@1325:   unsigned int extract_card_num(julong v) {
johnc@1325:     return (v & card_num_mask_in_place) >> card_num_shift;
johnc@1325:   }
johnc@1325: 
johnc@1325:   typedef struct {
johnc@1325:     unsigned char _count;
johnc@1325:     unsigned char _evict_count;
johnc@1325:   } CardCountCacheEntry;
johnc@1325: 
johnc@1325:   CardCountCacheEntry* _card_counts;
johnc@1325:   CardEpochCacheEntry* _card_epochs;
johnc@1325: 
johnc@1325:   // The current number of buckets in the card count cache
johnc@1325:   unsigned _n_card_counts;
johnc@1325: 
johnc@1325:   // The max number of buckets required for the number of
johnc@1325:   // cards for the entire reserved heap
johnc@1325:   unsigned _max_n_card_counts;
johnc@1325: 
johnc@1325:   // Possible sizes of the cache: odd primes that roughly double in size.
johnc@1325:   // (See jvmtiTagMap.cpp).
johnc@1325:   static int _cc_cache_sizes[];
johnc@1325: 
johnc@1325:   // The index in _cc_cache_sizes corresponding to the size of
johnc@1325:   // _card_counts.
johnc@1325:   int _cache_size_index;
johnc@1325: 
johnc@1325:   bool _expand_card_counts;
johnc@1325: 
johnc@1325:   const jbyte* _ct_bot;
johnc@1324: 
johnc@1324:   jbyte**      _hot_cache;
johnc@1324:   int          _hot_cache_size;
johnc@1324:   int          _n_hot;
johnc@1324:   int          _hot_cache_idx;
johnc@1324: 
johnc@1324:   int          _hot_cache_par_chunk_size;
johnc@1324:   volatile int _hot_cache_par_claimed_idx;
ysr@777: 
johnc@1325:   // Needed to workaround 6817995
johnc@1325:   CardTableModRefBS* _ct_bs;
johnc@1325:   G1CollectedHeap*   _g1h;
johnc@1325: 
johnc@1325:   // Expands the array that holds the card counts to the next size up
johnc@1325:   void expand_card_count_cache();
johnc@1325: 
johnc@1325:   // hash a given key (index of card_ptr) with the specified size
johnc@1325:   static unsigned int hash(size_t key, int size) {
johnc@1325:     return (unsigned int) key % size;
johnc@1325:   }
johnc@1325: 
johnc@1325:   // hash a given key (index of card_ptr)
johnc@1325:   unsigned int hash(size_t key) {
johnc@1325:     return hash(key, _n_card_counts);
johnc@1325:   }
johnc@1325: 
johnc@1325:   unsigned ptr_2_card_num(jbyte* card_ptr) {
johnc@1325:     return (unsigned) (card_ptr - _ct_bot);
johnc@1325:   }
johnc@1325: 
johnc@1325:   jbyte* card_num_2_ptr(unsigned card_num) {
johnc@1325:     return (jbyte*) (_ct_bot + card_num);
johnc@1325:   }
johnc@1325: 
ysr@777:   // Returns the count of this card after incrementing it.
johnc@1325:   jbyte* add_card_count(jbyte* card_ptr, int* count, bool* defer);
ysr@777: 
johnc@1325:   // Returns true if this card is in a young region
johnc@1325:   bool is_young_card(jbyte* card_ptr);
johnc@1325: 
ysr@777:  public:
ysr@777:   ConcurrentG1Refine();
ysr@777:   ~ConcurrentG1Refine();
ysr@777: 
ysr@777:   void init(); // Accomplish some initialization that has to wait.
iveresov@1229:   void stop();
ysr@777: 
iveresov@1229:   // Iterate over the conc refine threads
iveresov@1229:   void threads_do(ThreadClosure *tc);
ysr@777: 
ysr@777:   // If this is the first entry for the slot, writes into the cache and
ysr@777:   // returns NULL.  If it causes an eviction, returns the evicted pointer.
ysr@777:   // Otherwise, its a cache hit, and returns NULL.
johnc@1325:   jbyte* cache_insert(jbyte* card_ptr, bool* defer);
ysr@777: 
ysr@777:   // Process the cached entries.
ysr@777:   void clean_up_cache(int worker_i, G1RemSet* g1rs);
ysr@777: 
johnc@1324:   // Set up for parallel processing of the cards in the hot cache
johnc@1324:   void clear_hot_cache_claimed_index() {
johnc@1324:     _hot_cache_par_claimed_idx = 0;
johnc@1324:   }
johnc@1324: 
ysr@777:   // Discard entries in the hot cache.
ysr@777:   void clear_hot_cache() {
ysr@777:     _hot_cache_idx = 0; _n_hot = 0;
ysr@777:   }
ysr@777: 
ysr@777:   bool hot_cache_is_empty() { return _n_hot == 0; }
ysr@777: 
ysr@777:   bool use_cache() { return _use_cache; }
ysr@777:   void set_use_cache(bool b) {
ysr@777:     if (b) _use_cache = _def_use_cache;
ysr@777:     else   _use_cache = false;
ysr@777:   }
ysr@777: 
ysr@777:   void clear_and_record_card_counts();
iveresov@1230: 
iveresov@1230:   static size_t thread_num();
tonyp@1454: 
tonyp@1454:   void print_worker_threads_on(outputStream* st) const;
ysr@777: };