1 /*
   2  * Copyright (c) 2001, 2014, 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_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_INLINE_HPP
  26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_INLINE_HPP
  27 
  28 #include "gc_implementation/g1/g1BlockOffsetTable.hpp"
  29 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
  30 #include "gc_implementation/g1/heapRegion.inline.hpp"
  31 #include "memory/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 #define check_index(index, msg)                                                \
  51   assert((index) < (_reserved.word_size() >> LogN_words),                      \
  52          err_msg("%s - index: "SIZE_FORMAT", _vs.committed_size: "SIZE_FORMAT, \
  53                  msg, (index), (_reserved.word_size() >> LogN_words)));        \
  54   assert(G1CollectedHeap::heap()->is_in_exact(address_for_index_raw(index)),   \
  55          err_msg("Index "SIZE_FORMAT" corresponding to "PTR_FORMAT             \
  56                  " (%u) is not in committed area.",                            \
  57                  (index),                                                      \
  58                  p2i(address_for_index_raw(index)),                            \
  59                  G1CollectedHeap::heap()->addr_to_region(address_for_index_raw(index))));
  60 
  61 u_char G1BlockOffsetSharedArray::offset_array(size_t index) const {
  62   check_index(index, "index out of range");
  63   return _offset_array[index];
  64 }
  65 
  66 void G1BlockOffsetSharedArray::set_offset_array(size_t index, u_char offset) {
  67   check_index(index, "index out of range");
  68   set_offset_array_raw(index, offset);
  69 }
  70 
  71 void G1BlockOffsetSharedArray::set_offset_array(size_t index, HeapWord* high, HeapWord* low) {
  72   check_index(index, "index out of range");
  73   assert(high >= low, "addresses out of order");
  74   size_t offset = pointer_delta(high, low);
  75   check_offset(offset, "offset too large");
  76   set_offset_array(index, (u_char)offset);
  77 }
  78 
  79 void G1BlockOffsetSharedArray::set_offset_array(size_t left, size_t right, u_char offset) {
  80   check_index(right, "right index out of range");
  81   assert(left <= right, "indexes out of order");
  82   size_t num_cards = right - left + 1;
  83   if (UseMemSetInBOT) {
  84     memset(&_offset_array[left], offset, num_cards);
  85   } else {
  86     size_t i = left;
  87     const size_t end = i + num_cards;
  88     for (; i < end; i++) {
  89       _offset_array[i] = offset;
  90     }
  91   }
  92 }
  93 
  94 // Variant of index_for that does not check the index for validity.
  95 inline size_t G1BlockOffsetSharedArray::index_for_raw(const void* p) const {
  96   return pointer_delta((char*)p, _reserved.start(), sizeof(char)) >> LogN;
  97 }
  98 
  99 inline size_t G1BlockOffsetSharedArray::index_for(const void* p) const {
 100   char* pc = (char*)p;
 101   assert(pc >= (char*)_reserved.start() &&
 102          pc <  (char*)_reserved.end(),
 103          err_msg("p (" PTR_FORMAT ") not in reserved [" PTR_FORMAT ", " PTR_FORMAT ")",
 104                  p2i(p), p2i(_reserved.start()), p2i(_reserved.end())));
 105   size_t result = index_for_raw(p);
 106   check_index(result, "bad index from address");
 107   return result;
 108 }
 109 
 110 inline HeapWord*
 111 G1BlockOffsetSharedArray::address_for_index(size_t index) const {
 112   check_index(index, "index out of range");
 113   HeapWord* result = address_for_index_raw(index);
 114   assert(result >= _reserved.start() && result < _reserved.end(),
 115          err_msg("bad address from index result " PTR_FORMAT
 116                  " _reserved.start() " PTR_FORMAT " _reserved.end() "
 117                  PTR_FORMAT,
 118                  p2i(result), p2i(_reserved.start()), p2i(_reserved.end())));
 119   return result;
 120 }
 121 
 122 #undef check_index
 123 
 124 inline size_t
 125 G1BlockOffsetArray::block_size(const HeapWord* p) const {
 126   return gsp()->block_size(p);
 127 }
 128 
 129 inline HeapWord*
 130 G1BlockOffsetArray::block_at_or_preceding(const void* addr,
 131                                           bool has_max_index,
 132                                           size_t max_index) const {
 133   assert(_array->offset_array(0) == 0, "objects can't cross covered areas");
 134   size_t index = _array->index_for(addr);
 135   // We must make sure that the offset table entry we use is valid.  If
 136   // "addr" is past the end, start at the last known one and go forward.
 137   if (has_max_index) {
 138     index = MIN2(index, max_index);
 139   }
 140   HeapWord* q = _array->address_for_index(index);
 141 
 142   uint offset = _array->offset_array(index);  // Extend u_char to uint.
 143   while (offset >= N_words) {
 144     // The excess of the offset from N_words indicates a power of Base
 145     // to go back by.
 146     size_t n_cards_back = BlockOffsetArray::entry_to_cards_back(offset);
 147     q -= (N_words * n_cards_back);
 148     assert(q >= gsp()->bottom(), "Went below bottom!");
 149     index -= n_cards_back;
 150     offset = _array->offset_array(index);
 151   }
 152   assert(offset < N_words, "offset too large");
 153   q -= offset;
 154   return q;
 155 }
 156 
 157 inline HeapWord*
 158 G1BlockOffsetArray::
 159 forward_to_block_containing_addr_const(HeapWord* q, HeapWord* n,
 160                                        const void* addr) const {
 161   if (addr >= gsp()->top()) return gsp()->top();
 162   while (n <= addr) {
 163     q = n;
 164     oop obj = oop(q);
 165     if (obj->klass_or_null() == NULL) return q;
 166     n += block_size(q);
 167   }
 168   assert(q <= n, "wrong order for q and addr");
 169   assert(addr < n, "wrong order for addr and n");
 170   return q;
 171 }
 172 
 173 inline HeapWord*
 174 G1BlockOffsetArray::forward_to_block_containing_addr(HeapWord* q,
 175                                                      const void* addr) {
 176   if (oop(q)->klass_or_null() == NULL) return q;
 177   HeapWord* n = q + block_size(q);
 178   // In the normal case, where the query "addr" is a card boundary, and the
 179   // offset table chunks are the same size as cards, the block starting at
 180   // "q" will contain addr, so the test below will fail, and we'll fall
 181   // through quickly.
 182   if (n <= addr) {
 183     q = forward_to_block_containing_addr_slow(q, n, addr);
 184   }
 185   assert(q <= addr, "wrong order for current and arg");
 186   return q;
 187 }
 188 
 189 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_INLINE_HPP