--- old/src/hotspot/share/memory/metaspace/occupancyMap.hpp 2019-07-25 15:30:14.413588122 +0200 +++ /dev/null 2019-07-25 13:07:35.456009699 +0200 @@ -1,242 +0,0 @@ -/* - * Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2018 SAP SE. 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_MEMORY_METASPACE_OCCUPANCYMAP_HPP -#define SHARE_MEMORY_METASPACE_OCCUPANCYMAP_HPP - -#include "memory/allocation.hpp" -#include "utilities/debug.hpp" -#include "utilities/globalDefinitions.hpp" - - -namespace metaspace { - -class Metachunk; - -// Helper for Occupancy Bitmap. A type trait to give an all-bits-are-one-unsigned constant. -template struct all_ones { static const T value; }; -template <> struct all_ones { static const uint64_t value = 0xFFFFFFFFFFFFFFFFULL; }; -template <> struct all_ones { static const uint32_t value = 0xFFFFFFFF; }; - -// The OccupancyMap is a bitmap which, for a given VirtualSpaceNode, -// keeps information about -// - where a chunk starts -// - whether a chunk is in-use or free -// A bit in this bitmap represents one range of memory in the smallest -// chunk size (SpecializedChunk or ClassSpecializedChunk). -class OccupancyMap : public CHeapObj { - - // The address range this map covers. - const MetaWord* const _reference_address; - const size_t _word_size; - - // The word size of a specialized chunk, aka the number of words one - // bit in this map represents. - const size_t _smallest_chunk_word_size; - - // map data - // Data are organized in two bit layers: - // The first layer is the chunk-start-map. Here, a bit is set to mark - // the corresponding region as the head of a chunk. - // The second layer is the in-use-map. Here, a set bit indicates that - // the corresponding belongs to a chunk which is in use. - uint8_t* _map[2]; - - enum { layer_chunk_start_map = 0, layer_in_use_map = 1 }; - - // length, in bytes, of bitmap data - size_t _map_size; - - // Returns true if bit at position pos at bit-layer layer is set. - bool get_bit_at_position(unsigned pos, unsigned layer) const { - assert(layer == 0 || layer == 1, "Invalid layer %d", layer); - const unsigned byteoffset = pos / 8; - assert(byteoffset < _map_size, - "invalid byte offset (%u), map size is " SIZE_FORMAT ".", byteoffset, _map_size); - const unsigned mask = 1 << (pos % 8); - return (_map[layer][byteoffset] & mask) > 0; - } - - // Changes bit at position pos at bit-layer layer to value v. - void set_bit_at_position(unsigned pos, unsigned layer, bool v) { - assert(layer == 0 || layer == 1, "Invalid layer %d", layer); - const unsigned byteoffset = pos / 8; - assert(byteoffset < _map_size, - "invalid byte offset (%u), map size is " SIZE_FORMAT ".", byteoffset, _map_size); - const unsigned mask = 1 << (pos % 8); - if (v) { - _map[layer][byteoffset] |= mask; - } else { - _map[layer][byteoffset] &= ~mask; - } - } - - // Optimized case of is_any_bit_set_in_region for 32/64bit aligned access: - // pos is 32/64 aligned and num_bits is 32/64. - // This is the typical case when coalescing to medium chunks, whose size is - // 32 or 64 times the specialized chunk size (depending on class or non class - // case), so they occupy 64 bits which should be 64bit aligned, because - // chunks are chunk-size aligned. - template - bool is_any_bit_set_in_region_3264(unsigned pos, unsigned num_bits, unsigned layer) const { - assert(_map_size > 0, "not initialized"); - assert(layer == 0 || layer == 1, "Invalid layer %d.", layer); - assert(pos % (sizeof(T) * 8) == 0, "Bit position must be aligned (%u).", pos); - assert(num_bits == (sizeof(T) * 8), "Number of bits incorrect (%u).", num_bits); - const size_t byteoffset = pos / 8; - assert(byteoffset <= (_map_size - sizeof(T)), - "Invalid byte offset (" SIZE_FORMAT "), map size is " SIZE_FORMAT ".", byteoffset, _map_size); - const T w = *(T*)(_map[layer] + byteoffset); - return w > 0 ? true : false; - } - - // Returns true if any bit in region [pos1, pos1 + num_bits) is set in bit-layer layer. - bool is_any_bit_set_in_region(unsigned pos, unsigned num_bits, unsigned layer) const { - if (pos % 32 == 0 && num_bits == 32) { - return is_any_bit_set_in_region_3264(pos, num_bits, layer); - } else if (pos % 64 == 0 && num_bits == 64) { - return is_any_bit_set_in_region_3264(pos, num_bits, layer); - } else { - for (unsigned n = 0; n < num_bits; n ++) { - if (get_bit_at_position(pos + n, layer)) { - return true; - } - } - } - return false; - } - - // Returns true if any bit in region [p, p+word_size) is set in bit-layer layer. - bool is_any_bit_set_in_region(MetaWord* p, size_t word_size, unsigned layer) const { - assert(word_size % _smallest_chunk_word_size == 0, - "Region size " SIZE_FORMAT " not a multiple of smallest chunk size.", word_size); - const unsigned pos = get_bitpos_for_address(p); - const unsigned num_bits = (unsigned) (word_size / _smallest_chunk_word_size); - return is_any_bit_set_in_region(pos, num_bits, layer); - } - - // Optimized case of set_bits_of_region for 32/64bit aligned access: - // pos is 32/64 aligned and num_bits is 32/64. - // This is the typical case when coalescing to medium chunks, whose size - // is 32 or 64 times the specialized chunk size (depending on class or non - // class case), so they occupy 64 bits which should be 64bit aligned, - // because chunks are chunk-size aligned. - template - void set_bits_of_region_T(unsigned pos, unsigned num_bits, unsigned layer, bool v) { - assert(pos % (sizeof(T) * 8) == 0, "Bit position must be aligned to %u (%u).", - (unsigned)(sizeof(T) * 8), pos); - assert(num_bits == (sizeof(T) * 8), "Number of bits incorrect (%u), expected %u.", - num_bits, (unsigned)(sizeof(T) * 8)); - const size_t byteoffset = pos / 8; - assert(byteoffset <= (_map_size - sizeof(T)), - "invalid byte offset (" SIZE_FORMAT "), map size is " SIZE_FORMAT ".", byteoffset, _map_size); - T* const pw = (T*)(_map[layer] + byteoffset); - *pw = v ? all_ones::value : (T) 0; - } - - // Set all bits in a region starting at pos to a value. - void set_bits_of_region(unsigned pos, unsigned num_bits, unsigned layer, bool v) { - assert(_map_size > 0, "not initialized"); - assert(layer == 0 || layer == 1, "Invalid layer %d.", layer); - if (pos % 32 == 0 && num_bits == 32) { - set_bits_of_region_T(pos, num_bits, layer, v); - } else if (pos % 64 == 0 && num_bits == 64) { - set_bits_of_region_T(pos, num_bits, layer, v); - } else { - for (unsigned n = 0; n < num_bits; n ++) { - set_bit_at_position(pos + n, layer, v); - } - } - } - - // Helper: sets all bits in a region [p, p+word_size). - void set_bits_of_region(MetaWord* p, size_t word_size, unsigned layer, bool v) { - assert(word_size % _smallest_chunk_word_size == 0, - "Region size " SIZE_FORMAT " not a multiple of smallest chunk size.", word_size); - const unsigned pos = get_bitpos_for_address(p); - const unsigned num_bits = (unsigned) (word_size / _smallest_chunk_word_size); - set_bits_of_region(pos, num_bits, layer, v); - } - - // Helper: given an address, return the bit position representing that address. - unsigned get_bitpos_for_address(const MetaWord* p) const { - assert(_reference_address != NULL, "not initialized"); - assert(p >= _reference_address && p < _reference_address + _word_size, - "Address %p out of range for occupancy map [%p..%p).", - p, _reference_address, _reference_address + _word_size); - assert(is_aligned(p, _smallest_chunk_word_size * sizeof(MetaWord)), - "Address not aligned (%p).", p); - const ptrdiff_t d = (p - _reference_address) / _smallest_chunk_word_size; - assert(d >= 0 && (size_t)d < _map_size * 8, "Sanity."); - return (unsigned) d; - } - - public: - - OccupancyMap(const MetaWord* reference_address, size_t word_size, size_t smallest_chunk_word_size); - ~OccupancyMap(); - - // Returns true if at address x a chunk is starting. - bool chunk_starts_at_address(MetaWord* p) const { - const unsigned pos = get_bitpos_for_address(p); - return get_bit_at_position(pos, layer_chunk_start_map); - } - - void set_chunk_starts_at_address(MetaWord* p, bool v) { - const unsigned pos = get_bitpos_for_address(p); - set_bit_at_position(pos, layer_chunk_start_map, v); - } - - // Removes all chunk-start-bits inside a region, typically as a - // result of a chunk merge. - void wipe_chunk_start_bits_in_region(MetaWord* p, size_t word_size) { - set_bits_of_region(p, word_size, layer_chunk_start_map, false); - } - - // Returns true if there are life (in use) chunks in the region limited - // by [p, p+word_size). - bool is_region_in_use(MetaWord* p, size_t word_size) const { - return is_any_bit_set_in_region(p, word_size, layer_in_use_map); - } - - // Marks the region starting at p with the size word_size as in use - // or free, depending on v. - void set_region_in_use(MetaWord* p, size_t word_size, bool v) { - set_bits_of_region(p, word_size, layer_in_use_map, v); - } - - // Verify occupancy map for the address range [from, to). - // We need to tell it the address range, because the memory the - // occupancy map is covering may not be fully comitted yet. - DEBUG_ONLY(void verify(MetaWord* from, MetaWord* to);) - - // Verify that a given chunk is correctly accounted for in the bitmap. - DEBUG_ONLY(void verify_for_chunk(Metachunk* chunk);) - -}; - -} // namespace metaspace - -#endif // SHARE_MEMORY_METASPACE_OCCUPANCYMAP_HPP