| /* |
| * Copyright (c) 2005, 2014, 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. |
| * |
| */ |
| |
| #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PARMARKBITMAP_HPP |
| #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PARMARKBITMAP_HPP |
| |
| #include "memory/memRegion.hpp" |
| #include "oops/oop.hpp" |
| #include "utilities/bitMap.hpp" |
| |
| class ParMarkBitMapClosure; |
| class PSVirtualSpace; |
| |
| class ParMarkBitMap: public CHeapObj<mtGC> |
| { |
| public: |
| typedef BitMap::idx_t idx_t; |
| |
| // Values returned by the iterate() methods. |
| enum IterationStatus { incomplete, complete, full, would_overflow }; |
| |
| inline ParMarkBitMap(); |
| 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); |
| |
| // 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; |
| |
| // 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_obj) 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. 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; |
| |
| size_t reserved_byte_size() const { return _reserved_byte_size; } |
| |
| // 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); |
| |
| // 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); |
| |
| void print_on_error(outputStream* st) const { |
| st->print_cr("Marking Bits: (ParMarkBitMap*) " PTR_FORMAT, p2i(this)); |
| _beg_bits.print_on_error(st, " Begin Bits: "); |
| _end_bits.print_on_error(st, " End Bits: "); |
| } |
| |
| #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); } |
| static inline int obj_granularity_shift() { return LogMinObjAlignment; } |
| |
| HeapWord* _region_start; |
| size_t _region_size; |
| BitMap _beg_bits; |
| BitMap _end_bits; |
| PSVirtualSpace* _virtual_space; |
| size_t _reserved_byte_size; |
| }; |
| |
| inline ParMarkBitMap::ParMarkBitMap(): |
| _beg_bits(), _end_bits(), _region_start(NULL), _region_size(0), _virtual_space(NULL), _reserved_byte_size(0) |
| { } |
| |
| 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 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_shift(); |
| } |
| |
| inline ParMarkBitMap::idx_t |
| ParMarkBitMap::words_to_bits(size_t words) |
| { |
| return words >> obj_granularity_shift(); |
| } |
| |
| 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.get_next_one_offset_inline(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 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.get_next_one_offset_inline_aligned_right(beg, end); |
| } |
| |
| inline ParMarkBitMap::idx_t |
| ParMarkBitMap::find_obj_end(idx_t beg, idx_t end) const |
| { |
| return _end_bits.get_next_one_offset_inline_aligned_right(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(), |
| err_msg("addr too small, addr: " PTR_FORMAT " region start: " PTR_FORMAT, p2i(addr), p2i(region_start()))); |
| assert(addr <= region_end(), |
| err_msg("addr too big, addr: " PTR_FORMAT " region end: " PTR_FORMAT, p2i(addr), p2i(region_end()))); |
| } |
| #endif // #ifdef ASSERT |
| |
| #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PARMARKBITMAP_HPP |