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

Thu, 05 Jun 2008 15:57:56 -0700

author
ysr
date
Thu, 05 Jun 2008 15:57:56 -0700
changeset 777
37f87013dfd8
child 1280
df6caf649ff7
permissions
-rw-r--r--

6711316: Open source the Garbage-First garbage collector
Summary: First mercurial integration of the code for the Garbage-First garbage collector.
Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr

     1 /*
     2  * Copyright 2001-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 inline HeapWord* G1BlockOffsetTable::block_start(const void* addr) {
    26   if (addr >= _bottom && addr < _end) {
    27     return block_start_unsafe(addr);
    28   } else {
    29     return NULL;
    30   }
    31 }
    33 inline HeapWord*
    34 G1BlockOffsetTable::block_start_const(const void* addr) const {
    35   if (addr >= _bottom && addr < _end) {
    36     return block_start_unsafe_const(addr);
    37   } else {
    38     return NULL;
    39   }
    40 }
    42 inline size_t G1BlockOffsetSharedArray::index_for(const void* p) const {
    43   char* pc = (char*)p;
    44   assert(pc >= (char*)_reserved.start() &&
    45          pc <  (char*)_reserved.end(),
    46          "p not in range.");
    47   size_t delta = pointer_delta(pc, _reserved.start(), sizeof(char));
    48   size_t result = delta >> LogN;
    49   assert(result < _vs.committed_size(), "bad index from address");
    50   return result;
    51 }
    53 inline HeapWord*
    54 G1BlockOffsetSharedArray::address_for_index(size_t index) const {
    55   assert(index < _vs.committed_size(), "bad index");
    56   HeapWord* result = _reserved.start() + (index << LogN_words);
    57   assert(result >= _reserved.start() && result < _reserved.end(),
    58          "bad address from index");
    59   return result;
    60 }
    62 inline HeapWord*
    63 G1BlockOffsetArray::block_at_or_preceding(const void* addr,
    64                                           bool has_max_index,
    65                                           size_t max_index) const {
    66   assert(_array->offset_array(0) == 0, "objects can't cross covered areas");
    67   size_t index = _array->index_for(addr);
    68   // We must make sure that the offset table entry we use is valid.  If
    69   // "addr" is past the end, start at the last known one and go forward.
    70   if (has_max_index) {
    71     index = MIN2(index, max_index);
    72   }
    73   HeapWord* q = _array->address_for_index(index);
    75   uint offset = _array->offset_array(index);  // Extend u_char to uint.
    76   while (offset >= N_words) {
    77     // The excess of the offset from N_words indicates a power of Base
    78     // to go back by.
    79     size_t n_cards_back = BlockOffsetArray::entry_to_cards_back(offset);
    80     q -= (N_words * n_cards_back);
    81     assert(q >= _sp->bottom(), "Went below bottom!");
    82     index -= n_cards_back;
    83     offset = _array->offset_array(index);
    84   }
    85   assert(offset < N_words, "offset too large");
    86   q -= offset;
    87   return q;
    88 }
    90 inline HeapWord*
    91 G1BlockOffsetArray::
    92 forward_to_block_containing_addr_const(HeapWord* q, HeapWord* n,
    93                                        const void* addr) const {
    94   if (csp() != NULL) {
    95     if (addr >= csp()->top()) return csp()->top();
    96     while (n <= addr) {
    97       q = n;
    98       oop obj = oop(q);
    99       if (obj->klass() == NULL) return q;
   100       n += obj->size();
   101     }
   102   } else {
   103     while (n <= addr) {
   104       q = n;
   105       oop obj = oop(q);
   106       if (obj->klass() == NULL) return q;
   107       n += _sp->block_size(q);
   108     }
   109   }
   110   assert(q <= n, "wrong order for q and addr");
   111   assert(addr < n, "wrong order for addr and n");
   112   return q;
   113 }
   115 inline HeapWord*
   116 G1BlockOffsetArray::forward_to_block_containing_addr(HeapWord* q,
   117                                                      const void* addr) {
   118   if (oop(q)->klass() == NULL) return q;
   119   HeapWord* n = q + _sp->block_size(q);
   120   // In the normal case, where the query "addr" is a card boundary, and the
   121   // offset table chunks are the same size as cards, the block starting at
   122   // "q" will contain addr, so the test below will fail, and we'll fall
   123   // through quickly.
   124   if (n <= addr) {
   125     q = forward_to_block_containing_addr_slow(q, n, addr);
   126   }
   127   assert(q <= addr, "wrong order for current and arg");
   128   return q;
   129 }
   131 //////////////////////////////////////////////////////////////////////////
   132 // BlockOffsetArrayNonContigSpace inlines
   133 //////////////////////////////////////////////////////////////////////////
   134 inline void G1BlockOffsetArray::freed(HeapWord* blk_start, HeapWord* blk_end) {
   135   // Verify that the BOT shows [blk_start, blk_end) to be one block.
   136   verify_single_block(blk_start, blk_end);
   137   // adjust _unallocated_block upward or downward
   138   // as appropriate
   139   if (BlockOffsetArrayUseUnallocatedBlock) {
   140     assert(_unallocated_block <= _end,
   141            "Inconsistent value for _unallocated_block");
   142     if (blk_end >= _unallocated_block && blk_start <= _unallocated_block) {
   143       // CMS-specific note: a block abutting _unallocated_block to
   144       // its left is being freed, a new block is being added or
   145       // we are resetting following a compaction
   146       _unallocated_block = blk_start;
   147     }
   148   }
   149 }
   151 inline void G1BlockOffsetArray::freed(HeapWord* blk, size_t size) {
   152   freed(blk, blk + size);
   153 }

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