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/heapRegion.hpp"
  30 #include "memory/space.hpp"
  31 
  32 inline HeapWord* G1BlockOffsetTable::block_start(const void* addr) {
  33   if (addr >= _bottom && addr < _end) {
  34     return block_start_unsafe(addr);
  35   } else {
  36     return NULL;
  37   }
  38 }
  39 
  40 inline HeapWord*
  41 G1BlockOffsetTable::block_start_const(const void* addr) const {
  42   if (addr >= _bottom && addr < _end) {
  43     return block_start_unsafe_const(addr);
  44   } else {
  45     return NULL;
  46   }
  47 }
  48 
  49 inline size_t G1BlockOffsetSharedArray::index_for(const void* p) const {
  50   char* pc = (char*)p;
  51   assert(pc >= (char*)_reserved.start() &&
  52          pc <  (char*)_reserved.end(),
  53          err_msg("p (" PTR_FORMAT ") not in reserved [" PTR_FORMAT ", " PTR_FORMAT ")",
  54                  p2i(p), p2i(_reserved.start()), p2i(_reserved.end())));
  55   size_t delta = pointer_delta(pc, _reserved.start(), sizeof(char));
  56   size_t result = delta >> LogN;
  57   check_index(result, "bad index from address");
  58   return result;
  59 }
  60 
  61 inline HeapWord*
  62 G1BlockOffsetSharedArray::address_for_index(size_t index) const {
  63   check_index(index, "index out of range");
  64   HeapWord* result = _reserved.start() + (index << LogN_words);
  65   assert(result >= _reserved.start() && result < _reserved.end(),
  66          err_msg("bad address from index result " PTR_FORMAT
  67                  " _reserved.start() " PTR_FORMAT " _reserved.end() "
  68                  PTR_FORMAT,
  69                  p2i(result), p2i(_reserved.start()), p2i(_reserved.end())));
  70   return result;
  71 }
  72 
  73 inline size_t
  74 G1BlockOffsetArray::block_size(const HeapWord* p) const {
  75   return gsp()->block_size(p);
  76 }
  77 
  78 inline HeapWord*
  79 G1BlockOffsetArray::block_at_or_preceding(const void* addr,
  80                                           bool has_max_index,
  81                                           size_t max_index) const {
  82   assert(_array->offset_array(0) == 0, "objects can't cross covered areas");
  83   size_t index = _array->index_for(addr);
  84   // We must make sure that the offset table entry we use is valid.  If
  85   // "addr" is past the end, start at the last known one and go forward.
  86   if (has_max_index) {
  87     index = MIN2(index, max_index);
  88   }
  89   HeapWord* q = _array->address_for_index(index);
  90 
  91   uint offset = _array->offset_array(index);  // Extend u_char to uint.
  92   while (offset >= N_words) {
  93     // The excess of the offset from N_words indicates a power of Base
  94     // to go back by.
  95     size_t n_cards_back = BlockOffsetArray::entry_to_cards_back(offset);
  96     q -= (N_words * n_cards_back);
  97     assert(q >= gsp()->bottom(), "Went below bottom!");
  98     index -= n_cards_back;
  99     offset = _array->offset_array(index);
 100   }
 101   assert(offset < N_words, "offset too large");
 102   q -= offset;
 103   return q;
 104 }
 105 
 106 inline HeapWord*
 107 G1BlockOffsetArray::
 108 forward_to_block_containing_addr_const(HeapWord* q, HeapWord* n,
 109                                        const void* addr) const {
 110   if (addr >= gsp()->top()) return gsp()->top();
 111   while (n <= addr) {
 112     q = n;
 113     oop obj = oop(q);
 114     if (obj->klass_or_null() == NULL) return q;
 115     n += block_size(q);
 116   }
 117   assert(q <= n, "wrong order for q and addr");
 118   assert(addr < n, "wrong order for addr and n");
 119   return q;
 120 }
 121 
 122 inline HeapWord*
 123 G1BlockOffsetArray::forward_to_block_containing_addr(HeapWord* q,
 124                                                      const void* addr) {
 125   if (oop(q)->klass_or_null() == NULL) return q;
 126   HeapWord* n = q + block_size(q);
 127   // In the normal case, where the query "addr" is a card boundary, and the
 128   // offset table chunks are the same size as cards, the block starting at
 129   // "q" will contain addr, so the test below will fail, and we'll fall
 130   // through quickly.
 131   if (n <= addr) {
 132     q = forward_to_block_containing_addr_slow(q, n, addr);
 133   }
 134   assert(q <= addr, "wrong order for current and arg");
 135   return q;
 136 }
 137 
 138 //////////////////////////////////////////////////////////////////////////
 139 // BlockOffsetArrayNonContigSpace inlines
 140 //////////////////////////////////////////////////////////////////////////
 141 inline void G1BlockOffsetArray::freed(HeapWord* blk_start, HeapWord* blk_end) {
 142   // Verify that the BOT shows [blk_start, blk_end) to be one block.
 143   verify_single_block(blk_start, blk_end);
 144   // adjust _unallocated_block upward or downward
 145   // as appropriate
 146   if (BlockOffsetArrayUseUnallocatedBlock) {
 147     assert(_unallocated_block <= _end,
 148            "Inconsistent value for _unallocated_block");
 149     if (blk_end >= _unallocated_block && blk_start <= _unallocated_block) {
 150       // CMS-specific note: a block abutting _unallocated_block to
 151       // its left is being freed, a new block is being added or
 152       // we are resetting following a compaction
 153       _unallocated_block = blk_start;
 154     }
 155   }
 156 }
 157 
 158 inline void G1BlockOffsetArray::freed(HeapWord* blk, size_t size) {
 159   freed(blk, blk + size);
 160 }
 161 
 162 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_INLINE_HPP