Mercurial > hg > graal-jvmci-8
diff src/share/vm/gc_implementation/parallelScavenge/parMarkBitMap.hpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | 37f87013dfd8 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/gc_implementation/parallelScavenge/parMarkBitMap.hpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,427 @@ +/* + * Copyright 2005-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +class oopDesc; +class ParMarkBitMapClosure; + +class ParMarkBitMap: public CHeapObj +{ +public: + typedef BitMap::idx_t idx_t; + + // Values returned by the iterate() methods. + enum IterationStatus { incomplete, complete, full, would_overflow }; + + inline ParMarkBitMap(); + inline ParMarkBitMap(MemRegion covered_region); + bool initialize(MemRegion covered_region); + + // Atomically mark an object as live. + bool mark_obj(HeapWord* addr, size_t size); + inline bool mark_obj(oop obj, int size); + inline bool mark_obj(oop obj); + + // Return whether the specified begin or end bit is set. + inline bool is_obj_beg(idx_t bit) const; + inline bool is_obj_end(idx_t bit) const; + + // Traditional interface for testing whether an object is marked or not (these + // test only the begin bits). + inline bool is_marked(idx_t bit) const; + inline bool is_marked(HeapWord* addr) const; + inline bool is_marked(oop obj) const; + + inline bool is_unmarked(idx_t bit) const; + inline bool is_unmarked(HeapWord* addr) const; + inline bool is_unmarked(oop obj) const; + + // Convert sizes from bits to HeapWords and back. An object that is n bits + // long will be bits_to_words(n) words long. An object that is m words long + // will take up words_to_bits(m) bits in the bitmap. + inline static size_t bits_to_words(idx_t bits); + inline static idx_t words_to_bits(size_t words); + + // Return the size in words of an object given a begin bit and an end bit, or + // the equivalent beg_addr and end_addr. + inline size_t obj_size(idx_t beg_bit, idx_t end_bit) const; + inline size_t obj_size(HeapWord* beg_addr, HeapWord* end_addr) const; + + // Return the size in words of the object (a search is done for the end bit). + inline size_t obj_size(idx_t beg_bit) const; + inline size_t obj_size(HeapWord* addr) const; + inline size_t obj_size(oop obj) const; + + // Synonyms for the above. + size_t obj_size_in_words(oop obj) const { return obj_size((HeapWord*)obj); } + size_t obj_size_in_words(HeapWord* addr) const { return obj_size(addr); } + + // Apply live_closure to each live object that lies completely within the + // range [live_range_beg, live_range_end). This is used to iterate over the + // compacted region of the heap. Return values: + // + // incomplete The iteration is not complete. The last object that + // begins in the range does not end in the range; + // closure->source() is set to the start of that object. + // + // complete The iteration is complete. All objects in the range + // were processed and the closure is not full; + // closure->source() is set one past the end of the range. + // + // full The closure is full; closure->source() is set to one + // past the end of the last object processed. + // + // would_overflow The next object in the range would overflow the closure; + // closure->source() is set to the start of that object. + IterationStatus iterate(ParMarkBitMapClosure* live_closure, + idx_t range_beg, idx_t range_end) const; + inline IterationStatus iterate(ParMarkBitMapClosure* live_closure, + HeapWord* range_beg, + HeapWord* range_end) const; + + // Apply live closure as above and additionally apply dead_closure to all dead + // space in the range [range_beg, dead_range_end). Note that dead_range_end + // must be >= range_end. This is used to iterate over the dense prefix. + // + // This method assumes that if the first bit in the range (range_beg) is not + // marked, then dead space begins at that point and the dead_closure is + // applied. Thus callers must ensure that range_beg is not in the middle of a + // live object. + IterationStatus iterate(ParMarkBitMapClosure* live_closure, + ParMarkBitMapClosure* dead_closure, + idx_t range_beg, idx_t range_end, + idx_t dead_range_end) const; + inline IterationStatus iterate(ParMarkBitMapClosure* live_closure, + ParMarkBitMapClosure* dead_closure, + HeapWord* range_beg, + HeapWord* range_end, + HeapWord* dead_range_end) const; + + // Return the number of live words in the range [beg_addr, end_addr) due to + // objects that start in the range. If a live object extends onto the range, + // the caller must detect and account for any live words due to that object. + // If a live object extends beyond the end of the range, only the words within + // the range are included in the result. + size_t live_words_in_range(HeapWord* beg_addr, HeapWord* end_addr) const; + + // Same as the above, except the end of the range must be a live object, which + // is the case when updating pointers. This allows a branch to be removed + // from inside the loop. + size_t live_words_in_range(HeapWord* beg_addr, oop end_obj) const; + + inline HeapWord* region_start() const; + inline HeapWord* region_end() const; + inline size_t region_size() const; + inline size_t size() const; + + // Convert a heap address to/from a bit index. + inline idx_t addr_to_bit(HeapWord* addr) const; + inline HeapWord* bit_to_addr(idx_t bit) const; + + // Return the bit index of the first marked object that begins (or ends, + // respectively) in the range [beg, end). If no object is found, return end. + inline idx_t find_obj_beg(idx_t beg, idx_t end) const; + inline idx_t find_obj_end(idx_t beg, idx_t end) const; + + inline HeapWord* find_obj_beg(HeapWord* beg, HeapWord* end) const; + inline HeapWord* find_obj_end(HeapWord* beg, HeapWord* end) const; + + // Clear a range of bits or the entire bitmap (both begin and end bits are + // cleared). + inline void clear_range(idx_t beg, idx_t end); + inline void clear() { clear_range(0, size()); } + + // Return the number of bits required to represent the specified number of + // HeapWords, or the specified region. + static inline idx_t bits_required(size_t words); + static inline idx_t bits_required(MemRegion covered_region); + static inline idx_t words_required(MemRegion covered_region); + +#ifndef PRODUCT + // CAS statistics. + size_t cas_tries() { return _cas_tries; } + size_t cas_retries() { return _cas_retries; } + size_t cas_by_another() { return _cas_by_another; } + + void reset_counters(); +#endif // #ifndef PRODUCT + +#ifdef ASSERT + void verify_clear() const; + inline void verify_bit(idx_t bit) const; + inline void verify_addr(HeapWord* addr) const; +#endif // #ifdef ASSERT + +private: + // Each bit in the bitmap represents one unit of 'object granularity.' Objects + // are double-word aligned in 32-bit VMs, but not in 64-bit VMs, so the 32-bit + // granularity is 2, 64-bit is 1. + static inline size_t obj_granularity() { return size_t(MinObjAlignment); } + + HeapWord* _region_start; + size_t _region_size; + BitMap _beg_bits; + BitMap _end_bits; + PSVirtualSpace* _virtual_space; + +#ifndef PRODUCT + size_t _cas_tries; + size_t _cas_retries; + size_t _cas_by_another; +#endif // #ifndef PRODUCT +}; + +inline ParMarkBitMap::ParMarkBitMap(): + _beg_bits(NULL, 0), + _end_bits(NULL, 0) +{ + _region_start = 0; + _virtual_space = 0; +} + +inline ParMarkBitMap::ParMarkBitMap(MemRegion covered_region): + _beg_bits(NULL, 0), + _end_bits(NULL, 0) +{ + initialize(covered_region); +} + +inline void ParMarkBitMap::clear_range(idx_t beg, idx_t end) +{ + _beg_bits.clear_range(beg, end); + _end_bits.clear_range(beg, end); +} + +inline ParMarkBitMap::idx_t +ParMarkBitMap::bits_required(size_t words) +{ + // Need two bits (one begin bit, one end bit) for each unit of 'object + // granularity' in the heap. + return words_to_bits(words * 2); +} + +inline ParMarkBitMap::idx_t +ParMarkBitMap::bits_required(MemRegion covered_region) +{ + return bits_required(covered_region.word_size()); +} + +inline ParMarkBitMap::idx_t +ParMarkBitMap::words_required(MemRegion covered_region) +{ + return bits_required(covered_region) / BitsPerWord; +} + +inline HeapWord* +ParMarkBitMap::region_start() const +{ + return _region_start; +} + +inline HeapWord* +ParMarkBitMap::region_end() const +{ + return region_start() + region_size(); +} + +inline size_t +ParMarkBitMap::region_size() const +{ + return _region_size; +} + +inline size_t +ParMarkBitMap::size() const +{ + return _beg_bits.size(); +} + +inline bool ParMarkBitMap::is_obj_beg(idx_t bit) const +{ + return _beg_bits.at(bit); +} + +inline bool ParMarkBitMap::is_obj_end(idx_t bit) const +{ + return _end_bits.at(bit); +} + +inline bool ParMarkBitMap::is_marked(idx_t bit) const +{ + return is_obj_beg(bit); +} + +inline bool ParMarkBitMap::is_marked(HeapWord* addr) const +{ + return is_marked(addr_to_bit(addr)); +} + +inline bool ParMarkBitMap::is_marked(oop obj) const +{ + return is_marked((HeapWord*)obj); +} + +inline bool ParMarkBitMap::is_unmarked(idx_t bit) const +{ + return !is_marked(bit); +} + +inline bool ParMarkBitMap::is_unmarked(HeapWord* addr) const +{ + return !is_marked(addr); +} + +inline bool ParMarkBitMap::is_unmarked(oop obj) const +{ + return !is_marked(obj); +} + +inline size_t +ParMarkBitMap::bits_to_words(idx_t bits) +{ + return bits * obj_granularity(); +} + +inline ParMarkBitMap::idx_t +ParMarkBitMap::words_to_bits(size_t words) +{ + return words / obj_granularity(); +} + +inline size_t ParMarkBitMap::obj_size(idx_t beg_bit, idx_t end_bit) const +{ + DEBUG_ONLY(verify_bit(beg_bit);) + DEBUG_ONLY(verify_bit(end_bit);) + return bits_to_words(end_bit - beg_bit + 1); +} + +inline size_t +ParMarkBitMap::obj_size(HeapWord* beg_addr, HeapWord* end_addr) const +{ + DEBUG_ONLY(verify_addr(beg_addr);) + DEBUG_ONLY(verify_addr(end_addr);) + return pointer_delta(end_addr, beg_addr) + obj_granularity(); +} + +inline size_t ParMarkBitMap::obj_size(idx_t beg_bit) const +{ + const idx_t end_bit = _end_bits.find_next_one_bit(beg_bit, size()); + assert(is_marked(beg_bit), "obj not marked"); + assert(end_bit < size(), "end bit missing"); + return obj_size(beg_bit, end_bit); +} + +inline size_t ParMarkBitMap::obj_size(HeapWord* addr) const +{ + return obj_size(addr_to_bit(addr)); +} + +inline size_t ParMarkBitMap::obj_size(oop obj) const +{ + return obj_size((HeapWord*)obj); +} + +inline ParMarkBitMap::IterationStatus +ParMarkBitMap::iterate(ParMarkBitMapClosure* live_closure, + HeapWord* range_beg, + HeapWord* range_end) const +{ + return iterate(live_closure, addr_to_bit(range_beg), addr_to_bit(range_end)); +} + +inline ParMarkBitMap::IterationStatus +ParMarkBitMap::iterate(ParMarkBitMapClosure* live_closure, + ParMarkBitMapClosure* dead_closure, + HeapWord* range_beg, + HeapWord* range_end, + HeapWord* dead_range_end) const +{ + return iterate(live_closure, dead_closure, + addr_to_bit(range_beg), addr_to_bit(range_end), + addr_to_bit(dead_range_end)); +} + +inline bool +ParMarkBitMap::mark_obj(oop obj, int size) +{ + return mark_obj((HeapWord*)obj, (size_t)size); +} + +inline BitMap::idx_t +ParMarkBitMap::addr_to_bit(HeapWord* addr) const +{ + DEBUG_ONLY(verify_addr(addr);) + return words_to_bits(pointer_delta(addr, region_start())); +} + +inline HeapWord* +ParMarkBitMap::bit_to_addr(idx_t bit) const +{ + DEBUG_ONLY(verify_bit(bit);) + return region_start() + bits_to_words(bit); +} + +inline ParMarkBitMap::idx_t +ParMarkBitMap::find_obj_beg(idx_t beg, idx_t end) const +{ + return _beg_bits.find_next_one_bit(beg, end); +} + +inline ParMarkBitMap::idx_t +ParMarkBitMap::find_obj_end(idx_t beg, idx_t end) const +{ + return _end_bits.find_next_one_bit(beg, end); +} + +inline HeapWord* +ParMarkBitMap::find_obj_beg(HeapWord* beg, HeapWord* end) const +{ + const idx_t beg_bit = addr_to_bit(beg); + const idx_t end_bit = addr_to_bit(end); + const idx_t search_end = BitMap::word_align_up(end_bit); + const idx_t res_bit = MIN2(find_obj_beg(beg_bit, search_end), end_bit); + return bit_to_addr(res_bit); +} + +inline HeapWord* +ParMarkBitMap::find_obj_end(HeapWord* beg, HeapWord* end) const +{ + const idx_t beg_bit = addr_to_bit(beg); + const idx_t end_bit = addr_to_bit(end); + const idx_t search_end = BitMap::word_align_up(end_bit); + const idx_t res_bit = MIN2(find_obj_end(beg_bit, search_end), end_bit); + return bit_to_addr(res_bit); +} + +#ifdef ASSERT +inline void ParMarkBitMap::verify_bit(idx_t bit) const { + // Allow one past the last valid bit; useful for loop bounds. + assert(bit <= _beg_bits.size(), "bit out of range"); +} + +inline void ParMarkBitMap::verify_addr(HeapWord* addr) const { + // Allow one past the last valid address; useful for loop bounds. + assert(addr >= region_start(), "addr too small"); + assert(addr <= region_start() + region_size(), "addr too big"); +} +#endif // #ifdef ASSERT