Antonios Printezis b5c83abcd4 6928059: G1: command line parameter renaming
Rename G1 parameters to make them more consistent.

Reviewed-by: jmasa, johnc
2010-02-23 23:13:23 -05:00

226 lines
7.0 KiB
C++

/*
* Copyright 2001-2009 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
*/
// Forward decl
class ConcurrentG1RefineThread;
class G1RemSet;
class ConcurrentG1Refine: public CHeapObj {
ConcurrentG1RefineThread** _threads;
int _n_threads;
int _n_worker_threads;
/*
* The value of the update buffer queue length falls into one of 3 zones:
* green, yellow, red. If the value is in [0, green) nothing is
* done, the buffers are left unprocessed to enable the caching effect of the
* dirtied cards. In the yellow zone [green, yellow) the concurrent refinement
* threads are gradually activated. In [yellow, red) all threads are
* running. If the length becomes red (max queue length) the mutators start
* processing the buffers.
*
* There are some interesting cases (when G1UseAdaptiveConcRefinement
* is turned off):
* 1) green = yellow = red = 0. In this case the mutator will process all
* buffers. Except for those that are created by the deferred updates
* machinery during a collection.
* 2) green = 0. Means no caching. Can be a good way to minimize the
* amount of time spent updating rsets during a collection.
*/
int _green_zone;
int _yellow_zone;
int _red_zone;
int _thread_threshold_step;
// Reset the threshold step value based of the current zone boundaries.
void reset_threshold_step();
// The cache for card refinement.
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 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;
int _n_hot;
int _hot_cache_idx;
int _hot_cache_par_chunk_size;
volatile int _hot_cache_par_claimed_idx;
// 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;
}
// 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();
void init(); // Accomplish some initialization that has to wait.
void stop();
void reinitialize_threads();
// Iterate over the conc refine threads
void threads_do(ThreadClosure *tc);
// 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, bool* defer);
// Process the cached entries.
void clean_up_cache(int worker_i, G1RemSet* g1rs);
// Set up for parallel processing of the cards in the hot cache
void clear_hot_cache_claimed_index() {
_hot_cache_par_claimed_idx = 0;
}
// Discard entries in the hot cache.
void clear_hot_cache() {
_hot_cache_idx = 0; _n_hot = 0;
}
bool hot_cache_is_empty() { return _n_hot == 0; }
bool use_cache() { return _use_cache; }
void set_use_cache(bool b) {
if (b) _use_cache = _def_use_cache;
else _use_cache = false;
}
void clear_and_record_card_counts();
static int thread_num();
void print_worker_threads_on(outputStream* st) const;
void set_green_zone(int x) { _green_zone = x; }
void set_yellow_zone(int x) { _yellow_zone = x; }
void set_red_zone(int x) { _red_zone = x; }
int green_zone() const { return _green_zone; }
int yellow_zone() const { return _yellow_zone; }
int red_zone() const { return _red_zone; }
int total_thread_num() const { return _n_threads; }
int worker_thread_num() const { return _n_worker_threads; }
int thread_threshold_step() const { return _thread_threshold_step; }
};