1 /*
   2  * Copyright (c) 2001, 2015, 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.inline.hpp"
  30 #include "gc/shared/memset_with_concurrent_readers.hpp"
  31 #include "gc/shared/space.hpp"
  32 
  33 inline HeapWord* G1BlockOffsetTable::block_start(const void* addr) {
  34   if (addr >= _bottom && addr < _end) {
  35     return block_start_unsafe(addr);
  36   } else {
  37     return NULL;
  38   }
  39 }
  40 
  41 inline HeapWord*
  42 G1BlockOffsetTable::block_start_const(const void* addr) const {
  43   if (addr >= _bottom && addr < _end) {
  44     return block_start_unsafe_const(addr);
  45   } else {
  46     return NULL;
  47   }
  48 }
  49 
  50 u_char G1BlockOffsetSharedArray::offset_array(size_t index) const {
  51   check_index(index, "index out of range");
  52   return _offset_array[index];
  53 }
  54 
  55 void G1BlockOffsetSharedArray::set_offset_array(size_t index, u_char offset) {
  56   check_index(index, "index out of range");
  57   set_offset_array_raw(index, offset);
  58 }
  59 
  60 void G1BlockOffsetSharedArray::set_offset_array(size_t index, HeapWord* high, HeapWord* low) {
  61   check_index(index, "index out of range");
  62   assert(high >= low, "addresses out of order");
  63   size_t offset = pointer_delta(high, low);
  64   check_offset(offset, "offset too large");
  65   set_offset_array(index, (u_char)offset);
  66 }
  67 
  68 void G1BlockOffsetSharedArray::set_offset_array(size_t left, size_t right, u_char offset) {
  69   check_index(right, "right index out of range");
  70   assert(left <= right, "indexes out of order");
  71   size_t num_cards = right - left + 1;
  72   memset_with_concurrent_readers(&_offset_array[left], offset, num_cards);
  73 }
  74 
  75 // Variant of index_for that does not check the index for validity.
  76 inline size_t G1BlockOffsetSharedArray::index_for_raw(const void* p) const {
  77   return pointer_delta((char*)p, _reserved.start(), sizeof(char)) >> LogN;
  78 }
  79 
  80 inline size_t G1BlockOffsetSharedArray::index_for(const void* p) const {
  81   char* pc = (char*)p;
  82   assert(pc >= (char*)_reserved.start() &&
  83          pc <  (char*)_reserved.end(),
  84          err_msg("p (" PTR_FORMAT ") not in reserved [" PTR_FORMAT ", " PTR_FORMAT ")",
  85                  p2i(p), p2i(_reserved.start()), p2i(_reserved.end())));
  86   size_t result = index_for_raw(p);
  87   check_index(result, "bad index from address");
  88   return result;
  89 }
  90 
  91 inline HeapWord*
  92 G1BlockOffsetSharedArray::address_for_index(size_t index) const {
  93   check_index(index, "index out of range");
  94   HeapWord* result = address_for_index_raw(index);
  95   assert(result >= _reserved.start() && result < _reserved.end(),
  96          err_msg("bad address from index result " PTR_FORMAT
  97                  " _reserved.start() " PTR_FORMAT " _reserved.end() "
  98                  PTR_FORMAT,
  99                  p2i(result), p2i(_reserved.start()), p2i(_reserved.end())));
 100   return result;
 101 }
 102 
 103 inline size_t
 104 G1BlockOffsetArray::block_size(const HeapWord* p) const {
 105   return gsp()->block_size(p);
 106 }
 107 
 108 inline HeapWord*
 109 G1BlockOffsetArray::block_at_or_preceding(const void* addr,
 110                                           bool has_max_index,
 111                                           size_t max_index) const {
 112   assert(_array->offset_array(0) == 0, "objects can't cross covered areas");
 113   size_t index = _array->index_for(addr);
 114   // We must make sure that the offset table entry we use is valid.  If
 115   // "addr" is past the end, start at the last known one and go forward.
 116   if (has_max_index) {
 117     index = MIN2(index, max_index);
 118   }
 119   HeapWord* q = _array->address_for_index(index);
 120 
 121   uint offset = _array->offset_array(index);  // Extend u_char to uint.
 122   while (offset >= N_words) {
 123     // The excess of the offset from N_words indicates a power of Base
 124     // to go back by.
 125     size_t n_cards_back = BlockOffsetArray::entry_to_cards_back(offset);
 126     q -= (N_words * n_cards_back);
 127     assert(q >= gsp()->bottom(), "Went below bottom!");
 128     index -= n_cards_back;
 129     offset = _array->offset_array(index);
 130   }
 131   assert(offset < N_words, "offset too large");
 132   q -= offset;
 133   return q;
 134 }
 135 
 136 inline HeapWord*
 137 G1BlockOffsetArray::
 138 forward_to_block_containing_addr_const(HeapWord* q, HeapWord* n,
 139                                        const void* addr) const {
 140   if (addr >= gsp()->top()) return gsp()->top();
 141   while (n <= addr) {
 142     q = n;
 143     oop obj = oop(q);
 144     if (obj->klass_or_null() == NULL) return q;
 145     n += block_size(q);
 146   }
 147   assert(q <= n, "wrong order for q and addr");
 148   assert(addr < n, "wrong order for addr and n");
 149   return q;
 150 }
 151 
 152 inline HeapWord*
 153 G1BlockOffsetArray::forward_to_block_containing_addr(HeapWord* q,
 154                                                      const void* addr) {
 155   if (oop(q)->klass_or_null() == NULL) return q;
 156   HeapWord* n = q + block_size(q);
 157   // In the normal case, where the query "addr" is a card boundary, and the
 158   // offset table chunks are the same size as cards, the block starting at
 159   // "q" will contain addr, so the test below will fail, and we'll fall
 160   // through quickly.
 161   if (n <= addr) {
 162     q = forward_to_block_containing_addr_slow(q, n, addr);
 163   }
 164   assert(q <= addr, "wrong order for current and arg");
 165   return q;
 166 }
 167 
 168 #endif // SHARE_VM_GC_G1_G1BLOCKOFFSETTABLE_INLINE_HPP