1 /* 2 * Copyright (c) 2001, 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 #ifndef SHARE_VM_GC_G1_G1BLOCKOFFSETTABLE_INLINE_HPP 26 #define SHARE_VM_GC_G1_G1BLOCKOFFSETTABLE_INLINE_HPP 27 28 #include "gc/g1/g1BlockOffsetTable.hpp" 29 #include "gc/g1/heapRegion.hpp" 30 #include "gc/shared/memset_with_concurrent_readers.hpp" 31 #include "gc/shared/space.hpp" 32 33 inline HeapWord* G1BlockOffsetTablePart::block_start(const void* addr) { 34 if (addr >= _space->bottom() && addr < _space->end()) { 35 HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1); 36 return forward_to_block_containing_addr(q, addr); 37 } else { 38 return NULL; 39 } 40 } 41 42 inline HeapWord* G1BlockOffsetTablePart::block_start_const(const void* addr) const { 43 if (addr >= _space->bottom() && addr < _space->end()) { 44 HeapWord* q = block_at_or_preceding(addr, true, _next_offset_index-1); 45 HeapWord* n = q + block_size(q); 46 return forward_to_block_containing_addr_const(q, n, addr); 47 } else { 48 return NULL; 49 } 50 } 51 52 u_char G1BlockOffsetTable::offset_array(size_t index) const { 53 check_index(index, "index out of range"); 54 return _offset_array[index]; 55 } 56 57 void G1BlockOffsetTable::set_offset_array(size_t index, u_char offset) { 58 check_index(index, "index out of range"); 59 set_offset_array_raw(index, offset); 60 } 61 62 void G1BlockOffsetTable::set_offset_array(size_t index, HeapWord* high, HeapWord* low) { 63 check_index(index, "index out of range"); 64 assert(high >= low, "addresses out of order"); 65 size_t offset = pointer_delta(high, low); 66 check_offset(offset, "offset too large"); 67 set_offset_array(index, (u_char)offset); 68 } 69 70 void G1BlockOffsetTable::set_offset_array(size_t left, size_t right, u_char offset) { 71 check_index(right, "right index out of range"); 72 assert(left <= right, "indexes out of order"); 73 size_t num_cards = right - left + 1; 74 memset_with_concurrent_readers(&_offset_array[left], offset, num_cards); 75 } 76 77 // Variant of index_for that does not check the index for validity. 78 inline size_t G1BlockOffsetTable::index_for_raw(const void* p) const { 79 return pointer_delta((char*)p, _reserved.start(), sizeof(char)) >> BOTConstants::LogN; 80 } 81 82 inline size_t G1BlockOffsetTable::index_for(const void* p) const { 83 char* pc = (char*)p; 84 assert(pc >= (char*)_reserved.start() && 85 pc < (char*)_reserved.end(), 86 "p (" PTR_FORMAT ") not in reserved [" PTR_FORMAT ", " PTR_FORMAT ")", 87 p2i(p), p2i(_reserved.start()), p2i(_reserved.end())); 88 size_t result = index_for_raw(p); 89 check_index(result, "bad index from address"); 90 return result; 91 } 92 93 inline HeapWord* G1BlockOffsetTable::address_for_index(size_t index) const { 94 check_index(index, "index out of range"); 95 HeapWord* result = address_for_index_raw(index); 96 assert(result >= _reserved.start() && result < _reserved.end(), 97 "bad address from index result " PTR_FORMAT 98 " _reserved.start() " PTR_FORMAT " _reserved.end() " PTR_FORMAT, 99 p2i(result), p2i(_reserved.start()), p2i(_reserved.end())); 100 return result; 101 } 102 103 inline size_t G1BlockOffsetTablePart::block_size(const HeapWord* p) const { 104 return _space->block_size(p); 105 } 106 107 inline HeapWord* G1BlockOffsetTablePart::block_at_or_preceding(const void* addr, 108 bool has_max_index, 109 size_t max_index) const { 110 assert(_object_can_span || _bot->offset_array(_bot->index_for(_space->bottom())) == 0, 111 "normal objects can't cross region boundaries"); 112 size_t index = _bot->index_for(addr); 113 // We must make sure that the offset table entry we use is valid. If 114 // "addr" is past the end, start at the last known one and go forward. 115 if (has_max_index) { 116 index = MIN2(index, max_index); 117 } 118 HeapWord* q = _bot->address_for_index(index); 119 120 uint offset = _bot->offset_array(index); // Extend u_char to uint. 121 while (offset >= BOTConstants::N_words) { 122 // The excess of the offset from N_words indicates a power of Base 123 // to go back by. 124 size_t n_cards_back = BOTConstants::entry_to_cards_back(offset); 125 q -= (BOTConstants::N_words * n_cards_back); 126 index -= n_cards_back; 127 offset = _bot->offset_array(index); 128 } 129 assert(offset < BOTConstants::N_words, "offset too large"); 130 q -= offset; 131 return q; 132 } 133 134 inline HeapWord* G1BlockOffsetTablePart::forward_to_block_containing_addr_const(HeapWord* q, HeapWord* n, 135 const void* addr) const { 136 if (addr >= _space->top()) return _space->top(); 137 while (n <= addr) { 138 q = n; 139 oop obj = oop(q); 140 if (obj->klass_or_null_acquire() == NULL) { 141 return q; 142 } 143 n += block_size(q); 144 } 145 assert(q <= n, "wrong order for q and addr"); 146 assert(addr < n, "wrong order for addr and n"); 147 return q; 148 } 149 150 inline HeapWord* G1BlockOffsetTablePart::forward_to_block_containing_addr(HeapWord* q, 151 const void* addr) { 152 if (oop(q)->klass_or_null_acquire() == NULL) { 153 return q; 154 } 155 HeapWord* n = q + block_size(q); 156 // In the normal case, where the query "addr" is a card boundary, and the 157 // offset table chunks are the same size as cards, the block starting at 158 // "q" will contain addr, so the test below will fail, and we'll fall 159 // through quickly. 160 if (n <= addr) { 161 q = forward_to_block_containing_addr_slow(q, n, addr); 162 } 163 assert(q <= addr, "wrong order for current and arg"); 164 return q; 165 } 166 167 #endif // SHARE_VM_GC_G1_G1BLOCKOFFSETTABLE_INLINE_HPP