--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentG1Refine.hpp Mon Aug 03 12:59:30 2009 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentG1Refine.hpp Tue Aug 04 16:00:17 2009 -0700
@@ -29,18 +29,77 @@
class ConcurrentG1Refine: public CHeapObj {
ConcurrentG1RefineThread** _threads;
int _n_threads;
+
// The cache for card refinement.
- bool _use_cache;
- bool _def_use_cache;
- size_t _n_periods;
- size_t _total_cards;
- size_t _total_travs;
+ bool _use_cache;
+ bool _def_use_cache;
+
+ size_t _n_periods; // Used as clearing epoch
+
+ // An evicting cache of the number of times each card
+ // is accessed. Reduces, but does not eliminate, the amount
+ // of duplicated processing of dirty cards.
+
+ enum SomePrivateConstants {
+ epoch_bits = 32,
+ card_num_shift = epoch_bits,
+ epoch_mask = AllBits,
+ card_num_mask = AllBits,
+
+ // The initial cache size is approximately this fraction
+ // of a maximal cache (i.e. the size needed for all cards
+ // in the heap)
+ InitialCacheFraction = 512
+ };
+
+ const static julong card_num_mask_in_place =
+ (julong) card_num_mask << card_num_shift;
+
+ typedef struct {
+ julong _value; // | card_num | epoch |
+ } CardEpochCacheEntry;
+
+ julong make_epoch_entry(unsigned int card_num, unsigned int epoch) {
+ assert(0 <= card_num && card_num < _max_n_card_counts, "Bounds");
+ assert(0 <= epoch && epoch <= _n_periods, "must be");
+
+ return ((julong) card_num << card_num_shift) | epoch;
+ }
- unsigned char* _card_counts;
- unsigned _n_card_counts;
- const jbyte* _ct_bot;
- unsigned* _cur_card_count_histo;
- unsigned* _cum_card_count_histo;
+ unsigned int extract_epoch(julong v) {
+ return (v & epoch_mask);
+ }
+
+ unsigned int extract_card_num(julong v) {
+ return (v & card_num_mask_in_place) >> card_num_shift;
+ }
+
+ typedef struct {
+ unsigned char _count;
+ unsigned char _evict_count;
+ } CardCountCacheEntry;
+
+ CardCountCacheEntry* _card_counts;
+ CardEpochCacheEntry* _card_epochs;
+
+ // The current number of buckets in the card count cache
+ unsigned _n_card_counts;
+
+ // The max number of buckets required for the number of
+ // cards for the entire reserved heap
+ unsigned _max_n_card_counts;
+
+ // Possible sizes of the cache: odd primes that roughly double in size.
+ // (See jvmtiTagMap.cpp).
+ static int _cc_cache_sizes[];
+
+ // The index in _cc_cache_sizes corresponding to the size of
+ // _card_counts.
+ int _cache_size_index;
+
+ bool _expand_card_counts;
+
+ const jbyte* _ct_bot;
jbyte** _hot_cache;
int _hot_cache_size;
@@ -50,12 +109,37 @@
int _hot_cache_par_chunk_size;
volatile int _hot_cache_par_claimed_idx;
- // Returns the count of this card after incrementing it.
- int add_card_count(jbyte* card_ptr);
+ // Needed to workaround 6817995
+ CardTableModRefBS* _ct_bs;
+ G1CollectedHeap* _g1h;
+
+ // Expands the array that holds the card counts to the next size up
+ void expand_card_count_cache();
+
+ // hash a given key (index of card_ptr) with the specified size
+ static unsigned int hash(size_t key, int size) {
+ return (unsigned int) key % size;
+ }
- void print_card_count_histo_range(unsigned* histo, int from, int to,
- float& cum_card_pct,
- float& cum_travs_pct);
+ // hash a given key (index of card_ptr)
+ unsigned int hash(size_t key) {
+ return hash(key, _n_card_counts);
+ }
+
+ unsigned ptr_2_card_num(jbyte* card_ptr) {
+ return (unsigned) (card_ptr - _ct_bot);
+ }
+
+ jbyte* card_num_2_ptr(unsigned card_num) {
+ return (jbyte*) (_ct_bot + card_num);
+ }
+
+ // Returns the count of this card after incrementing it.
+ jbyte* add_card_count(jbyte* card_ptr, int* count, bool* defer);
+
+ // Returns true if this card is in a young region
+ bool is_young_card(jbyte* card_ptr);
+
public:
ConcurrentG1Refine();
~ConcurrentG1Refine();
@@ -69,7 +153,7 @@
// If this is the first entry for the slot, writes into the cache and
// returns NULL. If it causes an eviction, returns the evicted pointer.
// Otherwise, its a cache hit, and returns NULL.
- jbyte* cache_insert(jbyte* card_ptr);
+ jbyte* cache_insert(jbyte* card_ptr, bool* defer);
// Process the cached entries.
void clean_up_cache(int worker_i, G1RemSet* g1rs);
@@ -93,7 +177,6 @@
}
void clear_and_record_card_counts();
- void print_final_card_counts();
static size_t thread_num();
};