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

Thu, 21 Aug 2014 11:47:10 +0200

author
tschatzl
date
Thu, 21 Aug 2014 11:47:10 +0200
changeset 7051
1f1d373cd044
parent 6992
2c6ef90f030a
child 7256
0fcaab91d485
permissions
-rw-r--r--

8038423: G1: Decommit memory within heap
Summary: Allow G1 to decommit memory of arbitrary regions within the heap and their associated auxiliary data structures card table, BOT, hot card cache, and mark bitmaps.
Reviewed-by: mgerdin, brutisso, jwilhelm

     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  */
    25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_INLINE_HPP
    26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_INLINE_HPP
    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"
    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 }
    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 }
    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))));
    61 u_char G1BlockOffsetSharedArray::offset_array(size_t index) const {
    62   check_index(index, "index out of range");
    63   return _offset_array[index];
    64 }
    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 }
    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 }
    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 }
    94 void G1BlockOffsetSharedArray::check_offset_array(size_t index, HeapWord* high, HeapWord* low) const {
    95   check_index(index, "index out of range");
    96   assert(high >= low, "addresses out of order");
    97   check_offset(pointer_delta(high, low), "offset too large");
    98   assert(_offset_array[index] == pointer_delta(high, low), "Wrong offset");
    99 }
   101 // Variant of index_for that does not check the index for validity.
   102 inline size_t G1BlockOffsetSharedArray::index_for_raw(const void* p) const {
   103   return pointer_delta((char*)p, _reserved.start(), sizeof(char)) >> LogN;
   104 }
   106 inline size_t G1BlockOffsetSharedArray::index_for(const void* p) const {
   107   char* pc = (char*)p;
   108   assert(pc >= (char*)_reserved.start() &&
   109          pc <  (char*)_reserved.end(),
   110          err_msg("p (" PTR_FORMAT ") not in reserved [" PTR_FORMAT ", " PTR_FORMAT ")",
   111                  p2i(p), p2i(_reserved.start()), p2i(_reserved.end())));
   112   size_t result = index_for_raw(p);
   113   check_index(result, "bad index from address");
   114   return result;
   115 }
   117 inline HeapWord*
   118 G1BlockOffsetSharedArray::address_for_index(size_t index) const {
   119   check_index(index, "index out of range");
   120   HeapWord* result = address_for_index_raw(index);
   121   assert(result >= _reserved.start() && result < _reserved.end(),
   122          err_msg("bad address from index result " PTR_FORMAT
   123                  " _reserved.start() " PTR_FORMAT " _reserved.end() "
   124                  PTR_FORMAT,
   125                  p2i(result), p2i(_reserved.start()), p2i(_reserved.end())));
   126   return result;
   127 }
   129 #undef check_index
   131 inline size_t
   132 G1BlockOffsetArray::block_size(const HeapWord* p) const {
   133   return gsp()->block_size(p);
   134 }
   136 inline HeapWord*
   137 G1BlockOffsetArray::block_at_or_preceding(const void* addr,
   138                                           bool has_max_index,
   139                                           size_t max_index) const {
   140   assert(_array->offset_array(0) == 0, "objects can't cross covered areas");
   141   size_t index = _array->index_for(addr);
   142   // We must make sure that the offset table entry we use is valid.  If
   143   // "addr" is past the end, start at the last known one and go forward.
   144   if (has_max_index) {
   145     index = MIN2(index, max_index);
   146   }
   147   HeapWord* q = _array->address_for_index(index);
   149   uint offset = _array->offset_array(index);  // Extend u_char to uint.
   150   while (offset >= N_words) {
   151     // The excess of the offset from N_words indicates a power of Base
   152     // to go back by.
   153     size_t n_cards_back = BlockOffsetArray::entry_to_cards_back(offset);
   154     q -= (N_words * n_cards_back);
   155     assert(q >= gsp()->bottom(), "Went below bottom!");
   156     index -= n_cards_back;
   157     offset = _array->offset_array(index);
   158   }
   159   assert(offset < N_words, "offset too large");
   160   q -= offset;
   161   return q;
   162 }
   164 inline HeapWord*
   165 G1BlockOffsetArray::
   166 forward_to_block_containing_addr_const(HeapWord* q, HeapWord* n,
   167                                        const void* addr) const {
   168   if (addr >= gsp()->top()) return gsp()->top();
   169   while (n <= addr) {
   170     q = n;
   171     oop obj = oop(q);
   172     if (obj->klass_or_null() == NULL) return q;
   173     n += block_size(q);
   174   }
   175   assert(q <= n, "wrong order for q and addr");
   176   assert(addr < n, "wrong order for addr and n");
   177   return q;
   178 }
   180 inline HeapWord*
   181 G1BlockOffsetArray::forward_to_block_containing_addr(HeapWord* q,
   182                                                      const void* addr) {
   183   if (oop(q)->klass_or_null() == NULL) return q;
   184   HeapWord* n = q + block_size(q);
   185   // In the normal case, where the query "addr" is a card boundary, and the
   186   // offset table chunks are the same size as cards, the block starting at
   187   // "q" will contain addr, so the test below will fail, and we'll fall
   188   // through quickly.
   189   if (n <= addr) {
   190     q = forward_to_block_containing_addr_slow(q, n, addr);
   191   }
   192   assert(q <= addr, "wrong order for current and arg");
   193   return q;
   194 }
   196 //////////////////////////////////////////////////////////////////////////
   197 // BlockOffsetArrayNonContigSpace inlines
   198 //////////////////////////////////////////////////////////////////////////
   199 inline void G1BlockOffsetArray::freed(HeapWord* blk_start, HeapWord* blk_end) {
   200   // Verify that the BOT shows [blk_start, blk_end) to be one block.
   201   verify_single_block(blk_start, blk_end);
   202   // adjust _unallocated_block upward or downward
   203   // as appropriate
   204   if (BlockOffsetArrayUseUnallocatedBlock) {
   205     assert(_unallocated_block <= _end,
   206            "Inconsistent value for _unallocated_block");
   207     if (blk_end >= _unallocated_block && blk_start <= _unallocated_block) {
   208       // CMS-specific note: a block abutting _unallocated_block to
   209       // its left is being freed, a new block is being added or
   210       // we are resetting following a compaction
   211       _unallocated_block = blk_start;
   212     }
   213   }
   214 }
   216 inline void G1BlockOffsetArray::freed(HeapWord* blk, size_t size) {
   217   freed(blk, blk + size);
   218 }
   220 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_INLINE_HPP

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