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/*
* Copyright (c) 2013, 2019, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#ifndef SHARE_GC_G1_G1CARDCOUNTS_HPP
#define SHARE_GC_G1_G1CARDCOUNTS_HPP
#include "gc/g1/g1CardTable.hpp"
#include "gc/g1/g1RegionToSpaceMapper.hpp"
#include "memory/allocation.hpp"
#include "memory/virtualspace.hpp"
#include "utilities/globalDefinitions.hpp"
class CardTableBarrierSet;
class G1CardCounts;
class G1CollectedHeap;
class G1RegionToSpaceMapper;
class HeapRegion;
class G1CardCountsMappingChangedListener : public G1MappingChangedListener {
private:
G1CardCounts* _counts;
public:
void set_cardcounts(G1CardCounts* counts) { _counts = counts; }
virtual void on_commit(uint start_idx, size_t num_regions, bool zero_filled);
};
// Table to track the number of times a card has been refined. Once
// a card has been refined a certain number of times, it is
// considered 'hot' and its refinement is delayed by inserting the
// card into the hot card cache. The card will then be refined when
// it is evicted from the hot card cache, or when the hot card cache
// is 'drained' during the next evacuation pause.
class G1CardCounts: public CHeapObj<mtGC> {
public:
typedef CardTable::CardValue CardValue;
private:
G1CardCountsMappingChangedListener _listener;
G1CollectedHeap* _g1h;
G1CardTable* _ct;
// The table of counts
uint8_t* _card_counts;
// Max capacity of the reserved space for the counts table
size_t _reserved_max_card_num;
// CardTable bottom.
const CardValue* _ct_bot;
// Returns true if the card counts table has been reserved.
bool has_reserved_count_table() { return _card_counts != NULL; }
// Returns true if the card counts table has been reserved and committed.
bool has_count_table() {
return has_reserved_count_table();
}
size_t ptr_2_card_num(const CardValue* card_ptr) {
assert(card_ptr >= _ct_bot,
"Invalid card pointer: "
"card_ptr: " PTR_FORMAT ", "
"_ct_bot: " PTR_FORMAT,
p2i(card_ptr), p2i(_ct_bot));
size_t card_num = pointer_delta(card_ptr, _ct_bot, sizeof(CardValue));
assert(card_num < _reserved_max_card_num,
"card pointer out of range: " PTR_FORMAT, p2i(card_ptr));
return card_num;
}
CardValue* card_num_2_ptr(size_t card_num) {
assert(card_num < _reserved_max_card_num,
"card num out of range: " SIZE_FORMAT, card_num);
return (CardValue*) (_ct_bot + card_num);
}
// Clear the counts table for the given (exclusive) index range.
void clear_range(size_t from_card_num, size_t to_card_num);
public:
G1CardCounts(G1CollectedHeap* g1h);
// Return the number of slots needed for a card counts table
// that covers mem_region_words words.
static size_t compute_size(size_t mem_region_size_in_words);
// Returns how many bytes of the heap a single byte of the card counts table
// corresponds to.
static size_t heap_map_factor();
void initialize(G1RegionToSpaceMapper* mapper);
// Increments the refinement count for the given card.
// Returns the pre-increment count value.
uint add_card_count(CardValue* card_ptr);
// Returns true if the given count is high enough to be considered
// 'hot'; false otherwise.
bool is_hot(uint count);
// Clears the card counts for the cards spanned by the region
void clear_region(HeapRegion* hr);
// Clears the card counts for the cards spanned by the MemRegion
void clear_range(MemRegion mr);
// Clear the entire card counts table during GC.
void clear_all();
};
#endif // SHARE_GC_G1_G1CARDCOUNTS_HPP
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