1 /* 2 * Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "memory/allocation.hpp" 27 #include "memory/metaspace/metachunk.hpp" 28 #include "memory/metaspace/occupancyMap.hpp" 29 #include "memory/metaspace/virtualSpaceNode.hpp" 30 #include "utilities/align.hpp" 31 #include "utilities/copy.hpp" 32 #include "utilities/debug.hpp" 33 34 namespace metaspace { 35 36 size_t Metachunk::object_alignment() { 37 // Must align pointers and sizes to 8, 38 // so that 64 bit types get correctly aligned. 39 const size_t alignment = 8; 40 41 // Make sure that the Klass alignment also agree. 42 STATIC_ASSERT(alignment == (size_t)KlassAlignmentInBytes); 43 44 return alignment; 45 } 46 47 size_t Metachunk::overhead() { 48 return align_up(sizeof(Metachunk), object_alignment()) / BytesPerWord; 49 } 50 51 // Metachunk methods 52 53 Metachunk::Metachunk(ChunkIndex chunktype, bool is_class, size_t word_size, 54 VirtualSpaceNode* container) 55 : Metabase<Metachunk>(word_size), 56 _container(container), 57 _top(NULL), 58 _sentinel(CHUNK_SENTINEL), 59 _chunk_type(chunktype), 60 _is_class(is_class), 61 _origin(origin_normal), 62 _use_count(0) 63 { 64 _top = initial_top(); 65 set_is_tagged_free(false); 66 #ifdef ASSERT 67 mangle(uninitMetaWordVal); 68 verify(); 69 #endif 70 } 71 72 MetaWord* Metachunk::allocate(size_t word_size) { 73 MetaWord* result = NULL; 74 // If available, bump the pointer to allocate. 75 if (free_word_size() >= word_size) { 76 result = _top; 77 _top = _top + word_size; 78 } 79 return result; 80 } 81 82 // _bottom points to the start of the chunk including the overhead. 83 size_t Metachunk::used_word_size() const { 84 return pointer_delta(_top, bottom(), sizeof(MetaWord)); 85 } 86 87 size_t Metachunk::free_word_size() const { 88 return pointer_delta(end(), _top, sizeof(MetaWord)); 89 } 90 91 void Metachunk::print_on(outputStream* st) const { 92 st->print_cr("Metachunk:" 93 " bottom " PTR_FORMAT " top " PTR_FORMAT 94 " end " PTR_FORMAT " size " SIZE_FORMAT " (%s)", 95 p2i(bottom()), p2i(_top), p2i(end()), word_size(), 96 chunk_size_name(get_chunk_type())); 97 if (Verbose) { 98 st->print_cr(" used " SIZE_FORMAT " free " SIZE_FORMAT, 99 used_word_size(), free_word_size()); 100 } 101 } 102 103 #ifdef ASSERT 104 void Metachunk::mangle(juint word_value) { 105 // Overwrite the payload of the chunk and not the links that 106 // maintain list of chunks. 107 HeapWord* start = (HeapWord*)initial_top(); 108 size_t size = word_size() - overhead(); 109 Copy::fill_to_words(start, size, word_value); 110 } 111 112 void Metachunk::verify() const { 113 assert(is_valid_sentinel(), "Chunk " PTR_FORMAT ": sentinel invalid", p2i(this)); 114 const ChunkIndex chunk_type = get_chunk_type(); 115 assert(is_valid_chunktype(chunk_type), "Chunk " PTR_FORMAT ": Invalid chunk type.", p2i(this)); 116 if (chunk_type != HumongousIndex) { 117 assert(word_size() == get_size_for_nonhumongous_chunktype(chunk_type, is_class()), 118 "Chunk " PTR_FORMAT ": wordsize " SIZE_FORMAT " does not fit chunk type %s.", 119 p2i(this), word_size(), chunk_size_name(chunk_type)); 120 } 121 assert(is_valid_chunkorigin(get_origin()), "Chunk " PTR_FORMAT ": Invalid chunk origin.", p2i(this)); 122 assert(bottom() <= _top && _top <= (MetaWord*)end(), 123 "Chunk " PTR_FORMAT ": Chunk top out of chunk bounds.", p2i(this)); 124 125 // For non-humongous chunks, starting address shall be aligned 126 // to its chunk size. Humongous chunks start address is 127 // aligned to specialized chunk size. 128 const size_t required_alignment = 129 (chunk_type != HumongousIndex ? word_size() : get_size_for_nonhumongous_chunktype(SpecializedIndex, is_class())) * sizeof(MetaWord); 130 assert(is_aligned((address)this, required_alignment), 131 "Chunk " PTR_FORMAT ": (size " SIZE_FORMAT ") not aligned to " SIZE_FORMAT ".", 132 p2i(this), word_size() * sizeof(MetaWord), required_alignment); 133 } 134 135 #endif // ASSERT 136 137 // Helper, returns a descriptive name for the given index. 138 const char* chunk_size_name(ChunkIndex index) { 139 switch (index) { 140 case SpecializedIndex: 141 return "specialized"; 142 case SmallIndex: 143 return "small"; 144 case MediumIndex: 145 return "medium"; 146 case HumongousIndex: 147 return "humongous"; 148 default: 149 return "Invalid index"; 150 } 151 } 152 153 #ifdef ASSERT 154 void do_verify_chunk(Metachunk* chunk) { 155 guarantee(chunk != NULL, "Sanity"); 156 // Verify chunk itself; then verify that it is consistent with the 157 // occupany map of its containing node. 158 chunk->verify(); 159 VirtualSpaceNode* const vsn = chunk->container(); 160 OccupancyMap* const ocmap = vsn->occupancy_map(); 161 ocmap->verify_for_chunk(chunk); 162 } 163 #endif 164 165 void do_update_in_use_info_for_chunk(Metachunk* chunk, bool inuse) { 166 chunk->set_is_tagged_free(!inuse); 167 OccupancyMap* const ocmap = chunk->container()->occupancy_map(); 168 ocmap->set_region_in_use((MetaWord*)chunk, chunk->word_size(), inuse); 169 } 170 171 } // namespace metaspace 172