| /* |
| * Copyright (c) 2013, 2016, 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_VM_GC_G1_G1FROMCARDCACHE_HPP |
| #define SHARE_VM_GC_G1_G1FROMCARDCACHE_HPP |
| |
| #include "memory/allocation.hpp" |
| #include "utilities/ostream.hpp" |
| |
| // G1FromCardCache remembers the most recently processed card on the heap on |
| // a per-region and per-thread basis. |
| class G1FromCardCache : public AllStatic { |
| private: |
| // Array of card indices. Indexed by heap region (rows) and thread (columns) to minimize |
| // thread contention. |
| // This order minimizes the time to clear all entries for a given region during region |
| // freeing. I.e. a single clear of a single memory area instead of multiple separate |
| // accesses with a large stride per region. |
| static int** _cache; |
| static uint _max_regions; |
| static size_t _static_mem_size; |
| #ifdef ASSERT |
| static uint _max_workers; |
| |
| static void check_bounds(uint worker_id, uint region_idx) { |
| assert(worker_id < _max_workers, "Worker_id %u is larger than maximum %u", worker_id, _max_workers); |
| assert(region_idx < _max_regions, "Region_idx %u is larger than maximum %u", region_idx, _max_regions); |
| } |
| #endif |
| |
| public: |
| enum { |
| InvalidCard = -1 // Card value of an invalid card, i.e. a card index not otherwise used. |
| }; |
| |
| static void clear(uint region_idx); |
| |
| // Returns true if the given card is in the cache at the given location, or |
| // replaces the card at that location and returns false. |
| static bool contains_or_replace(uint worker_id, uint region_idx, int card) { |
| int card_in_cache = at(worker_id, region_idx); |
| if (card_in_cache == card) { |
| return true; |
| } else { |
| set(worker_id, region_idx, card); |
| return false; |
| } |
| } |
| |
| static int at(uint worker_id, uint region_idx) { |
| DEBUG_ONLY(check_bounds(worker_id, region_idx);) |
| return _cache[region_idx][worker_id]; |
| } |
| |
| static void set(uint worker_id, uint region_idx, int val) { |
| DEBUG_ONLY(check_bounds(worker_id, region_idx);) |
| _cache[region_idx][worker_id] = val; |
| } |
| |
| static void initialize(uint num_par_rem_sets, uint max_num_regions); |
| |
| static void invalidate(uint start_idx, size_t num_regions); |
| |
| static void print(outputStream* out = tty) PRODUCT_RETURN; |
| |
| static size_t static_mem_size() { |
| return _static_mem_size; |
| } |
| }; |
| |
| #endif // SHARE_VM_GC_G1_G1FROMCARDCACHE_HPP |