1 /*
2 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2018 SAP SE. All rights reserved.
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