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 "memory/space.hpp"
  30 
  31 inline HeapWord* G1BlockOffsetTable::block_start(const void* addr) {
  32   if (addr >= _bottom && addr < _end) {
  33     return block_start_unsafe(addr);
  34   } else {
  35     return NULL;
  36   }
  37 }
  38 
  39 inline HeapWord*
  40 G1BlockOffsetTable::block_start_const(const void* addr) const {
  41   if (addr >= _bottom && addr < _end) {
  42     return block_start_unsafe_const(addr);
  43   } else {
  44     return NULL;
  45   }
  46 }
  47 
  48 inline size_t G1BlockOffsetSharedArray::index_for(const void* p) const {
  49   char* pc = (char*)p;
  50   assert(pc >= (char*)_reserved.start() &&
  51          pc <  (char*)_reserved.end(),
  52          err_msg("p (" PTR_FORMAT ") not in reserved [" PTR_FORMAT ", " PTR_FORMAT ")",
  53                  p2i(p), p2i(_reserved.start()), p2i(_reserved.end())));
  54   size_t delta = pointer_delta(pc, _reserved.start(), sizeof(char));
  55   size_t result = delta >> LogN;
  56   check_index(result, "bad index from address");
  57   return result;
  58 }
  59 
  60 inline HeapWord*
  61 G1BlockOffsetSharedArray::address_for_index(size_t index) const {
  62   check_index(index, "index out of range");
  63   HeapWord* result = _reserved.start() + (index << LogN_words);
  64   assert(result >= _reserved.start() && result < _reserved.end(),
  65          err_msg("bad address from index result " PTR_FORMAT
  66                  " _reserved.start() " PTR_FORMAT " _reserved.end() "
  67                  PTR_FORMAT,
  68                  p2i(result), p2i(_reserved.start()), p2i(_reserved.end())));
  69   return result;
  70 }
  71 
  72 inline HeapWord*
  73 G1BlockOffsetArray::block_at_or_preceding(const void* addr,
  74                                           bool has_max_index,
  75                                           size_t max_index) const {
  76   assert(_array->offset_array(0) == 0, "objects can't cross covered areas");
  77   size_t index = _array->index_for(addr);
  78   // We must make sure that the offset table entry we use is valid.  If
  79   // "addr" is past the end, start at the last known one and go forward.
  80   if (has_max_index) {
  81     index = MIN2(index, max_index);
  82   }
  83   HeapWord* q = _array->address_for_index(index);
  84 
  85   uint offset = _array->offset_array(index);  // Extend u_char to uint.
  86   while (offset >= N_words) {
  87     // The excess of the offset from N_words indicates a power of Base
  88     // to go back by.
  89     size_t n_cards_back = BlockOffsetArray::entry_to_cards_back(offset);
  90     q -= (N_words * n_cards_back);
  91     assert(q >= _sp->bottom(), "Went below bottom!");
  92     index -= n_cards_back;
  93     offset = _array->offset_array(index);
  94   }
  95   assert(offset < N_words, "offset too large");
  96   q -= offset;
  97   return q;
  98 }
  99 
 100 inline HeapWord*
 101 G1BlockOffsetArray::
 102 forward_to_block_containing_addr_const(HeapWord* q, HeapWord* n,
 103                                        const void* addr) const {
 104   if (csp() != NULL) {
 105     if (addr >= csp()->top()) return csp()->top();
 106     while (n <= addr) {
 107       q = n;
 108       oop obj = oop(q);
 109       if (obj->klass_or_null() == NULL) return q;
 110       n += obj->size();
 111     }
 112   } else {
 113     while (n <= addr) {
 114       q = n;
 115       oop obj = oop(q);
 116       if (obj->klass_or_null() == NULL) return q;
 117       n += _sp->block_size(q);
 118     }
 119   }
 120   assert(q <= n, "wrong order for q and addr");
 121   assert(addr < n, "wrong order for addr and n");
 122   return q;
 123 }
 124 
 125 inline HeapWord*
 126 G1BlockOffsetArray::forward_to_block_containing_addr(HeapWord* q,
 127                                                      const void* addr) {
 128   if (oop(q)->klass_or_null() == NULL) return q;
 129   HeapWord* n = q + _sp->block_size(q);
 130   // In the normal case, where the query "addr" is a card boundary, and the
 131   // offset table chunks are the same size as cards, the block starting at
 132   // "q" will contain addr, so the test below will fail, and we'll fall
 133   // through quickly.
 134   if (n <= addr) {
 135     q = forward_to_block_containing_addr_slow(q, n, addr);
 136   }
 137   assert(q <= addr, "wrong order for current and arg");
 138   return q;
 139 }
 140 
 141 //////////////////////////////////////////////////////////////////////////
 142 // BlockOffsetArrayNonContigSpace inlines
 143 //////////////////////////////////////////////////////////////////////////
 144 inline void G1BlockOffsetArray::freed(HeapWord* blk_start, HeapWord* blk_end) {
 145   // Verify that the BOT shows [blk_start, blk_end) to be one block.
 146   verify_single_block(blk_start, blk_end);
 147   // adjust _unallocated_block upward or downward
 148   // as appropriate
 149   if (BlockOffsetArrayUseUnallocatedBlock) {
 150     assert(_unallocated_block <= _end,
 151            "Inconsistent value for _unallocated_block");
 152     if (blk_end >= _unallocated_block && blk_start <= _unallocated_block) {
 153       // CMS-specific note: a block abutting _unallocated_block to
 154       // its left is being freed, a new block is being added or
 155       // we are resetting following a compaction
 156       _unallocated_block = blk_start;
 157     }
 158   }
 159 }
 160 
 161 inline void G1BlockOffsetArray::freed(HeapWord* blk, size_t size) {
 162   freed(blk, blk + size);
 163 }
 164 
 165 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_INLINE_HPP