1 /* 2 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved. 3 * Copyright (c) 2018, SAP. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 * 24 */ 25 26 #include "precompiled.hpp" 27 #include "utilities/debug.hpp" 28 #include "utilities/globalDefinitions.hpp" 29 #include "memory/metaspace/metachunk.hpp" 30 #include "memory/metaspace/occupancyMap.hpp" 31 #include "runtime/os.hpp" 32 33 namespace metaspace { 34 35 OccupancyMap::OccupancyMap(const MetaWord* reference_address, size_t word_size, size_t smallest_chunk_word_size) : 36 _reference_address(reference_address), _word_size(word_size), 37 _smallest_chunk_word_size(smallest_chunk_word_size) 38 { 39 assert(reference_address != NULL, "invalid reference address"); 40 assert(is_aligned(reference_address, smallest_chunk_word_size), 41 "Reference address not aligned to smallest chunk size."); 42 assert(is_aligned(word_size, smallest_chunk_word_size), 43 "Word_size shall be a multiple of the smallest chunk size."); 44 // Calculate bitmap size: one bit per smallest_chunk_word_size'd area. 45 size_t num_bits = word_size / smallest_chunk_word_size; 46 _map_size = (num_bits + 7) / 8; 47 assert(_map_size * 8 >= num_bits, "sanity"); 48 _map[0] = (uint8_t*) os::malloc(_map_size, mtInternal); 49 _map[1] = (uint8_t*) os::malloc(_map_size, mtInternal); 50 assert(_map[0] != NULL && _map[1] != NULL, "Occupancy Map: allocation failed."); 51 memset(_map[1], 0, _map_size); 52 memset(_map[0], 0, _map_size); 53 // Sanity test: the first respectively last possible chunk start address in 54 // the covered range shall map to the first and last bit in the bitmap. 55 assert(get_bitpos_for_address(reference_address) == 0, 56 "First chunk address in range must map to fist bit in bitmap."); 57 assert(get_bitpos_for_address(reference_address + word_size - smallest_chunk_word_size) == num_bits - 1, 58 "Last chunk address in range must map to last bit in bitmap."); 59 } 60 61 OccupancyMap::~OccupancyMap() { 62 os::free(_map[0]); 63 os::free(_map[1]); 64 } 65 66 #ifdef ASSERT 67 // Verify occupancy map for the address range [from, to). 68 // We need to tell it the address range, because the memory the 69 // occupancy map is covering may not be fully comitted yet. 70 void OccupancyMap::verify(MetaWord* from, MetaWord* to) { 71 Metachunk* chunk = NULL; 72 int nth_bit_for_chunk = 0; 73 MetaWord* chunk_end = NULL; 74 for (MetaWord* p = from; p < to; p += _smallest_chunk_word_size) { 75 const unsigned pos = get_bitpos_for_address(p); 76 // Check the chunk-starts-info: 77 if (get_bit_at_position(pos, layer_chunk_start_map)) { 78 // Chunk start marked in bitmap. 79 chunk = (Metachunk*) p; 80 if (chunk_end != NULL) { 81 assert(chunk_end == p, "Unexpected chunk start found at %p (expected " 82 "the next chunk to start at %p).", p, chunk_end); 83 } 84 assert(chunk->is_valid_sentinel(), "Invalid chunk at address %p.", p); 85 if (chunk->get_chunk_type() != HumongousIndex) { 86 guarantee(is_aligned(p, chunk->word_size()), "Chunk %p not aligned.", p); 87 } 88 chunk_end = p + chunk->word_size(); 89 nth_bit_for_chunk = 0; 90 assert(chunk_end <= to, "Chunk end overlaps test address range."); 91 } else { 92 // No chunk start marked in bitmap. 93 assert(chunk != NULL, "Chunk should start at start of address range."); 94 assert(p < chunk_end, "Did not find expected chunk start at %p.", p); 95 nth_bit_for_chunk ++; 96 } 97 // Check the in-use-info: 98 const bool in_use_bit = get_bit_at_position(pos, layer_in_use_map); 99 if (in_use_bit) { 100 assert(!chunk->is_tagged_free(), "Chunk %p: marked in-use in map but is free (bit %u).", 101 chunk, nth_bit_for_chunk); 102 } else { 103 assert(chunk->is_tagged_free(), "Chunk %p: marked free in map but is in use (bit %u).", 104 chunk, nth_bit_for_chunk); 105 } 106 } 107 } 108 109 // Verify that a given chunk is correctly accounted for in the bitmap. 110 void OccupancyMap::verify_for_chunk(Metachunk* chunk) { 111 assert(chunk_starts_at_address((MetaWord*) chunk), 112 "No chunk start marked in map for chunk %p.", chunk); 113 // For chunks larger than the minimal chunk size, no other chunk 114 // must start in its area. 115 if (chunk->word_size() > _smallest_chunk_word_size) { 116 assert(!is_any_bit_set_in_region(((MetaWord*) chunk) + _smallest_chunk_word_size, 117 chunk->word_size() - _smallest_chunk_word_size, layer_chunk_start_map), 118 "No chunk must start within another chunk."); 119 } 120 if (!chunk->is_tagged_free()) { 121 assert(is_region_in_use((MetaWord*)chunk, chunk->word_size()), 122 "Chunk %p is in use but marked as free in map (%d %d).", 123 chunk, chunk->get_chunk_type(), chunk->get_origin()); 124 } else { 125 assert(!is_region_in_use((MetaWord*)chunk, chunk->word_size()), 126 "Chunk %p is free but marked as in-use in map (%d %d).", 127 chunk, chunk->get_chunk_type(), chunk->get_origin()); 128 } 129 } 130 131 #endif // ASSERT 132 133 } // namespace metaspace 134 135