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/metachunk.hpp" 28 #include "utilities/align.hpp" 29 #include "utilities/copy.hpp" 30 #include "utilities/debug.hpp" 31 32 class VirtualSpaceNode; 33 34 size_t Metachunk::object_alignment() { 35 // Must align pointers and sizes to 8, 36 // so that 64 bit types get correctly aligned. 37 const size_t alignment = 8; 38 39 // Make sure that the Klass alignment also agree. 40 STATIC_ASSERT(alignment == (size_t)KlassAlignmentInBytes); 41 42 return alignment; 43 } 44 45 size_t Metachunk::overhead() { 46 return align_up(sizeof(Metachunk), object_alignment()) / BytesPerWord; 47 } 48 49 // Metachunk methods 50 51 Metachunk::Metachunk(ChunkIndex chunktype, bool is_class, size_t word_size, 52 VirtualSpaceNode* container) 53 : Metabase<Metachunk>(word_size), 54 _chunk_type(chunktype), 55 _is_class(is_class), 56 _sentinel(CHUNK_SENTINEL), 57 _origin(origin_normal), 58 _use_count(0), 59 _top(NULL), 60 _container(container) 61 { 62 _top = initial_top(); 63 set_is_tagged_free(false); 64 #ifdef ASSERT 65 mangle(uninitMetaWordVal); 66 verify(); 67 #endif 68 } 69 70 MetaWord* Metachunk::allocate(size_t word_size) { 71 MetaWord* result = NULL; 72 // If available, bump the pointer to allocate. 73 if (free_word_size() >= word_size) { 74 result = _top; 75 _top = _top + word_size; 76 } 77 return result; 78 } 79 80 // _bottom points to the start of the chunk including the overhead. 81 size_t Metachunk::used_word_size() const { 82 return pointer_delta(_top, bottom(), sizeof(MetaWord)); 83 } 84 85 size_t Metachunk::free_word_size() const { 86 return pointer_delta(end(), _top, sizeof(MetaWord)); 87 } 88 89 void Metachunk::print_on(outputStream* st) const { 90 st->print_cr("Metachunk:" 91 " bottom " PTR_FORMAT " top " PTR_FORMAT 92 " end " PTR_FORMAT " size " SIZE_FORMAT " (%s)", 93 p2i(bottom()), p2i(_top), p2i(end()), word_size(), 94 chunk_size_name(get_chunk_type())); 95 if (Verbose) { 96 st->print_cr(" used " SIZE_FORMAT " free " SIZE_FORMAT, 97 used_word_size(), free_word_size()); 98 } 99 } 100 101 #ifdef ASSERT 102 void Metachunk::mangle(juint word_value) { 103 // Overwrite the payload of the chunk and not the links that 104 // maintain list of chunks. 105 HeapWord* start = (HeapWord*)initial_top(); 106 size_t size = word_size() - overhead(); 107 Copy::fill_to_words(start, size, word_value); 108 } 109 110 void Metachunk::verify() { 111 assert(is_valid_sentinel(), "Chunk " PTR_FORMAT ": sentinel invalid", p2i(this)); 112 const ChunkIndex chunk_type = get_chunk_type(); 113 assert(is_valid_chunktype(chunk_type), "Chunk " PTR_FORMAT ": Invalid chunk type.", p2i(this)); 114 if (chunk_type != HumongousIndex) { 115 assert(word_size() == get_size_for_nonhumongous_chunktype(chunk_type, is_class()), 116 "Chunk " PTR_FORMAT ": wordsize " SIZE_FORMAT " does not fit chunk type %s.", 117 p2i(this), word_size(), chunk_size_name(chunk_type)); 118 } 119 assert(is_valid_chunkorigin(get_origin()), "Chunk " PTR_FORMAT ": Invalid chunk origin.", p2i(this)); 120 assert(bottom() <= _top && _top <= (MetaWord*)end(), 121 "Chunk " PTR_FORMAT ": Chunk top out of chunk bounds.", p2i(this)); 122 123 // For non-humongous chunks, starting address shall be aligned 124 // to its chunk size. Humongous chunks start address is 125 // aligned to specialized chunk size. 126 const size_t required_alignment = 127 (chunk_type != HumongousIndex ? word_size() : get_size_for_nonhumongous_chunktype(SpecializedIndex, is_class())) * sizeof(MetaWord); 128 assert(is_aligned((address)this, required_alignment), 129 "Chunk " PTR_FORMAT ": (size " SIZE_FORMAT ") not aligned to " SIZE_FORMAT ".", 130 p2i(this), word_size() * sizeof(MetaWord), required_alignment); 131 } 132 133 #endif // ASSERT 134 135 // Helper, returns a descriptive name for the given index. 136 const char* chunk_size_name(ChunkIndex index) { 137 switch (index) { 138 case SpecializedIndex: 139 return "specialized"; 140 case SmallIndex: 141 return "small"; 142 case MediumIndex: 143 return "medium"; 144 case HumongousIndex: 145 return "humongous"; 146 default: 147 return "Invalid index"; 148 } 149 }