--- /dev/null 2015-10-06 23:29:51.451421828 +0200 +++ new/src/share/vm/gc/shared/cmBitMap.cpp 2015-10-08 22:16:06.910844422 +0200 @@ -0,0 +1,151 @@ +/* + * Copyright (c) 2015, 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. + * + */ + +// Concurrent marking bit map wrapper + +#include "gc/shared/cmBitMap.inline.hpp" +#include "utilities/bitMap.inline.hpp" + +CMBitMapRO::CMBitMapRO(int shifter) : + _bm(), + _shifter(shifter) { + _bmStartWord = 0; + _bmWordSize = 0; +} + +HeapWord* CMBitMapRO::getNextMarkedWordAddress(const HeapWord* addr, + const HeapWord* limit) const { + // First we must round addr *up* to a possible object boundary. + addr = (HeapWord*)align_size_up((intptr_t)addr, + HeapWordSize << _shifter); + size_t addrOffset = heapWordToOffset(addr); + if (limit == NULL) { + limit = _bmStartWord + _bmWordSize; + } + size_t limitOffset = heapWordToOffset(limit); + size_t nextOffset = _bm.get_next_one_offset(addrOffset, limitOffset); + HeapWord* nextAddr = offsetToHeapWord(nextOffset); + assert(nextAddr >= addr, "get_next_one postcondition"); + assert(nextAddr == limit || isMarked(nextAddr), + "get_next_one postcondition"); + return nextAddr; +} + +HeapWord* CMBitMapRO::getNextUnmarkedWordAddress(const HeapWord* addr, + const HeapWord* limit) const { + size_t addrOffset = heapWordToOffset(addr); + if (limit == NULL) { + limit = _bmStartWord + _bmWordSize; + } + size_t limitOffset = heapWordToOffset(limit); + size_t nextOffset = _bm.get_next_zero_offset(addrOffset, limitOffset); + HeapWord* nextAddr = offsetToHeapWord(nextOffset); + assert(nextAddr >= addr, "get_next_one postcondition"); + assert(nextAddr == limit || !isMarked(nextAddr), + "get_next_one postcondition"); + return nextAddr; +} + +int CMBitMapRO::heapWordDiffToOffsetDiff(size_t diff) const { + assert((diff & ((1 << _shifter) - 1)) == 0, "argument check"); + return (int) (diff >> _shifter); +} + +#ifndef PRODUCT +bool CMBitMapRO::covers(MemRegion heap_rs) const { + // assert(_bm.map() == _virtual_space.low(), "map inconsistency"); + assert(((size_t)_bm.size() * ((size_t)1 << _shifter)) == _bmWordSize, + "size inconsistency"); + return _bmStartWord == (HeapWord*)(heap_rs.start()) && + _bmWordSize == heap_rs.word_size(); +} +#endif + +void CMBitMapRO::print_on_error(outputStream* st, const char* prefix) const { + _bm.print_on_error(st, prefix); +} + +size_t CMBitMap::compute_size(size_t heap_size) { + return heap_size / mark_distance(); +} + +size_t CMBitMap::mark_distance() { + return MinObjAlignmentInBytes * BitsPerByte; +} + +void CMBitMap::initialize(MemRegion heap, MemRegion bitmap) { + _bmStartWord = heap.start(); + _bmWordSize = heap.word_size(); + + _bm.set_map((BitMap::bm_word_t*) bitmap.start()); + _bm.set_size(_bmWordSize >> _shifter); +} + +void CMBitMap::clearAll() { + _bm.clear(); +} + +void CMBitMap::markRange(MemRegion mr) { + mr.intersection(MemRegion(_bmStartWord, _bmWordSize)); + assert(!mr.is_empty(), "unexpected empty region"); + assert((offsetToHeapWord(heapWordToOffset(mr.end())) == + ((HeapWord *) mr.end())), + "markRange memory region end is not card aligned"); + // convert address range into offset range + _bm.at_put_range(heapWordToOffset(mr.start()), + heapWordToOffset(mr.end()), true); +} + +void CMBitMap::parMarkRange(MemRegion mr) { + mr.intersection(MemRegion(_bmStartWord, _bmWordSize)); + assert(!mr.is_empty(), "unexpected empty region"); + assert((offsetToHeapWord(heapWordToOffset(mr.end())) == + ((HeapWord *) mr.end())), + "markRange memory region end is not card aligned"); + // convert address range into offset range + _bm.par_at_put_range(heapWordToOffset(mr.start()), + heapWordToOffset(mr.end()), true); +} + +void CMBitMap::clearRange(MemRegion mr) { + mr.intersection(MemRegion(_bmStartWord, _bmWordSize)); + assert(!mr.is_empty(), "unexpected empty region"); + // convert address range into offset range + _bm.at_put_range(heapWordToOffset(mr.start()), + heapWordToOffset(mr.end()), false); +} + +MemRegion CMBitMap::getAndClearMarkedRegion(HeapWord* addr, + HeapWord* end_addr) { + HeapWord* start = getNextMarkedWordAddress(addr); + start = MIN2(start, end_addr); + HeapWord* end = getNextUnmarkedWordAddress(start); + end = MIN2(end, end_addr); + assert(start <= end, "Consistency check"); + MemRegion mr(start, end); + if (!mr.is_empty()) { + clearRange(mr); + } + return mr; +}