Mercurial > hg > graal-jvmci-8
view src/share/vm/gc_implementation/g1/g1BlockOffsetTable.inline.hpp @ 1886:72a161e62cc4
6991377: G1: race between concurrent refinement and humongous object allocation
Summary: There is a race between the concurrent refinement threads and the humongous object allocation that can cause the concurrent refinement threads to corrupt the part of the BOT that it is being initialized by the humongous object allocation operation. The solution is to do the humongous object allocation in careful steps to ensure that the concurrent refinement threads always have a consistent view over the BOT, region contents, and top. The fix includes some very minor tidying up in sparsePRT.
Reviewed-by: jcoomes, johnc, ysr
author | tonyp |
---|---|
date | Sat, 16 Oct 2010 17:12:19 -0400 |
parents | c18cbe5936b8 |
children | f95d63e2154a |
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/* * Copyright (c) 2001, 2007, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ inline HeapWord* G1BlockOffsetTable::block_start(const void* addr) { if (addr >= _bottom && addr < _end) { return block_start_unsafe(addr); } else { return NULL; } } inline HeapWord* G1BlockOffsetTable::block_start_const(const void* addr) const { if (addr >= _bottom && addr < _end) { return block_start_unsafe_const(addr); } else { return NULL; } } inline size_t G1BlockOffsetSharedArray::index_for(const void* p) const { char* pc = (char*)p; assert(pc >= (char*)_reserved.start() && pc < (char*)_reserved.end(), "p not in range."); size_t delta = pointer_delta(pc, _reserved.start(), sizeof(char)); size_t result = delta >> LogN; assert(result < _vs.committed_size(), "bad index from address"); return result; } inline HeapWord* G1BlockOffsetSharedArray::address_for_index(size_t index) const { assert(index < _vs.committed_size(), "bad index"); HeapWord* result = _reserved.start() + (index << LogN_words); assert(result >= _reserved.start() && result < _reserved.end(), "bad address from index"); return result; } inline HeapWord* G1BlockOffsetArray::block_at_or_preceding(const void* addr, bool has_max_index, size_t max_index) const { assert(_array->offset_array(0) == 0, "objects can't cross covered areas"); size_t index = _array->index_for(addr); // We must make sure that the offset table entry we use is valid. If // "addr" is past the end, start at the last known one and go forward. if (has_max_index) { index = MIN2(index, max_index); } HeapWord* q = _array->address_for_index(index); uint offset = _array->offset_array(index); // Extend u_char to uint. while (offset >= N_words) { // The excess of the offset from N_words indicates a power of Base // to go back by. size_t n_cards_back = BlockOffsetArray::entry_to_cards_back(offset); q -= (N_words * n_cards_back); assert(q >= _sp->bottom(), "Went below bottom!"); index -= n_cards_back; offset = _array->offset_array(index); } assert(offset < N_words, "offset too large"); q -= offset; return q; } inline HeapWord* G1BlockOffsetArray:: forward_to_block_containing_addr_const(HeapWord* q, HeapWord* n, const void* addr) const { if (csp() != NULL) { if (addr >= csp()->top()) return csp()->top(); while (n <= addr) { q = n; oop obj = oop(q); if (obj->klass_or_null() == NULL) return q; n += obj->size(); } } else { while (n <= addr) { q = n; oop obj = oop(q); if (obj->klass_or_null() == NULL) return q; n += _sp->block_size(q); } } assert(q <= n, "wrong order for q and addr"); assert(addr < n, "wrong order for addr and n"); return q; } inline HeapWord* G1BlockOffsetArray::forward_to_block_containing_addr(HeapWord* q, const void* addr) { if (oop(q)->klass_or_null() == NULL) return q; HeapWord* n = q + _sp->block_size(q); // In the normal case, where the query "addr" is a card boundary, and the // offset table chunks are the same size as cards, the block starting at // "q" will contain addr, so the test below will fail, and we'll fall // through quickly. if (n <= addr) { q = forward_to_block_containing_addr_slow(q, n, addr); } assert(q <= addr, "wrong order for current and arg"); return q; } ////////////////////////////////////////////////////////////////////////// // BlockOffsetArrayNonContigSpace inlines ////////////////////////////////////////////////////////////////////////// inline void G1BlockOffsetArray::freed(HeapWord* blk_start, HeapWord* blk_end) { // Verify that the BOT shows [blk_start, blk_end) to be one block. verify_single_block(blk_start, blk_end); // adjust _unallocated_block upward or downward // as appropriate if (BlockOffsetArrayUseUnallocatedBlock) { assert(_unallocated_block <= _end, "Inconsistent value for _unallocated_block"); if (blk_end >= _unallocated_block && blk_start <= _unallocated_block) { // CMS-specific note: a block abutting _unallocated_block to // its left is being freed, a new block is being added or // we are resetting following a compaction _unallocated_block = blk_start; } } } inline void G1BlockOffsetArray::freed(HeapWord* blk, size_t size) { freed(blk, blk + size); }