--- a/src/hotspot/share/memory/metaspace/occupancyMap.hpp Tue Sep 10 14:52:53 2019 +0800
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -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 <typename T> struct all_ones { static const T value; };
-template <> struct all_ones <uint64_t> { static const uint64_t value = 0xFFFFFFFFFFFFFFFFULL; };
-template <> struct all_ones <uint32_t> { 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<mtInternal> {
-
- // 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 <typename T>
- 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<uint32_t>(pos, num_bits, layer);
- } else if (pos % 64 == 0 && num_bits == 64) {
- return is_any_bit_set_in_region_3264<uint64_t>(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 <typename T>
- 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<T>::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<uint32_t>(pos, num_bits, layer, v);
- } else if (pos % 64 == 0 && num_bits == 64) {
- set_bits_of_region_T<uint64_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