--- /dev/null 2018-05-09 06:13:36.966491568 +0200 +++ new/src/hotspot/share/memory/metaspace/occupancyMap.cpp 2018-05-09 12:24:42.979658068 +0200 @@ -0,0 +1,137 @@ +/* + * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2018, SAP. + * 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. + * + */ + +#include "precompiled.hpp" +#include "utilities/debug.hpp" +#include "utilities/globalDefinitions.hpp" +#include "memory/metaspace/metachunk.hpp" +#include "memory/metaspace/occupancyMap.hpp" +#include "runtime/os.hpp" + +namespace metaspace { +namespace internals { + +OccupancyMap::OccupancyMap(const MetaWord* reference_address, size_t word_size, size_t smallest_chunk_word_size) : + _reference_address(reference_address), _word_size(word_size), + _smallest_chunk_word_size(smallest_chunk_word_size) +{ + assert(reference_address != NULL, "invalid reference address"); + assert(is_aligned(reference_address, smallest_chunk_word_size), + "Reference address not aligned to smallest chunk size."); + assert(is_aligned(word_size, smallest_chunk_word_size), + "Word_size shall be a multiple of the smallest chunk size."); + // Calculate bitmap size: one bit per smallest_chunk_word_size'd area. + size_t num_bits = word_size / smallest_chunk_word_size; + _map_size = (num_bits + 7) / 8; + assert(_map_size * 8 >= num_bits, "sanity"); + _map[0] = (uint8_t*) os::malloc(_map_size, mtInternal); + _map[1] = (uint8_t*) os::malloc(_map_size, mtInternal); + assert(_map[0] != NULL && _map[1] != NULL, "Occupancy Map: allocation failed."); + memset(_map[1], 0, _map_size); + memset(_map[0], 0, _map_size); + // Sanity test: the first respectively last possible chunk start address in + // the covered range shall map to the first and last bit in the bitmap. + assert(get_bitpos_for_address(reference_address) == 0, + "First chunk address in range must map to fist bit in bitmap."); + assert(get_bitpos_for_address(reference_address + word_size - smallest_chunk_word_size) == num_bits - 1, + "Last chunk address in range must map to last bit in bitmap."); +} + +OccupancyMap::~OccupancyMap() { + os::free(_map[0]); + os::free(_map[1]); +} + +#ifdef ASSERT +// 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. +void OccupancyMap::verify(MetaWord* from, MetaWord* to) { + Metachunk* chunk = NULL; + int nth_bit_for_chunk = 0; + MetaWord* chunk_end = NULL; + for (MetaWord* p = from; p < to; p += _smallest_chunk_word_size) { + const unsigned pos = get_bitpos_for_address(p); + // Check the chunk-starts-info: + if (get_bit_at_position(pos, layer_chunk_start_map)) { + // Chunk start marked in bitmap. + chunk = (Metachunk*) p; + if (chunk_end != NULL) { + assert(chunk_end == p, "Unexpected chunk start found at %p (expected " + "the next chunk to start at %p).", p, chunk_end); + } + assert(chunk->is_valid_sentinel(), "Invalid chunk at address %p.", p); + if (chunk->get_chunk_type() != HumongousIndex) { + guarantee(is_aligned(p, chunk->word_size()), "Chunk %p not aligned.", p); + } + chunk_end = p + chunk->word_size(); + nth_bit_for_chunk = 0; + assert(chunk_end <= to, "Chunk end overlaps test address range."); + } else { + // No chunk start marked in bitmap. + assert(chunk != NULL, "Chunk should start at start of address range."); + assert(p < chunk_end, "Did not find expected chunk start at %p.", p); + nth_bit_for_chunk ++; + } + // Check the in-use-info: + const bool in_use_bit = get_bit_at_position(pos, layer_in_use_map); + if (in_use_bit) { + assert(!chunk->is_tagged_free(), "Chunk %p: marked in-use in map but is free (bit %u).", + chunk, nth_bit_for_chunk); + } else { + assert(chunk->is_tagged_free(), "Chunk %p: marked free in map but is in use (bit %u).", + chunk, nth_bit_for_chunk); + } + } +} + +// Verify that a given chunk is correctly accounted for in the bitmap. +void OccupancyMap::verify_for_chunk(Metachunk* chunk) { + assert(chunk_starts_at_address((MetaWord*) chunk), + "No chunk start marked in map for chunk %p.", chunk); + // For chunks larger than the minimal chunk size, no other chunk + // must start in its area. + if (chunk->word_size() > _smallest_chunk_word_size) { + assert(!is_any_bit_set_in_region(((MetaWord*) chunk) + _smallest_chunk_word_size, + chunk->word_size() - _smallest_chunk_word_size, layer_chunk_start_map), + "No chunk must start within another chunk."); + } + if (!chunk->is_tagged_free()) { + assert(is_region_in_use((MetaWord*)chunk, chunk->word_size()), + "Chunk %p is in use but marked as free in map (%d %d).", + chunk, chunk->get_chunk_type(), chunk->get_origin()); + } else { + assert(!is_region_in_use((MetaWord*)chunk, chunk->word_size()), + "Chunk %p is free but marked as in-use in map (%d %d).", + chunk, chunk->get_chunk_type(), chunk->get_origin()); + } +} + +#endif // ASSERT + +} // namespace metaspace +} // namespace internals + +