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src/share/vm/gc/g1/g1BlockOffsetTable.inline.hpp

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rev 12504 : 8173764: G1 BOT wrongly assumes that objects must always begin at the start of G1BlockOffsetTablePart
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rev 12505 : [mq]: 8173764-rev-tschatzl
   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  *


  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;


   1 /*
   2  * Copyright (c) 2001, 2017, 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  *


  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          "Object crossed region boundary, found offset %u instead of 0",
 112          (uint) _bot->offset_array(_bot->index_for(_space->bottom())));
 113   size_t index = _bot->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 = _bot->address_for_index(index);
 120 
 121   uint offset = _bot->offset_array(index);  // Extend u_char to uint.
 122   while (offset >= BOTConstants::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 = BOTConstants::entry_to_cards_back(offset);
 126     q -= (BOTConstants::N_words * n_cards_back);
 127     index -= n_cards_back;
 128     offset = _bot->offset_array(index);
 129   }
 130   assert(offset < BOTConstants::N_words, "offset too large");
 131   q -= offset;
 132   return q;


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