| /* |
| * Copyright (c) 2005, 2017, 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 |
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| */ |
| |
| #ifndef SHARE_VM_GC_PARALLEL_PARMARKBITMAP_HPP |
| #define SHARE_VM_GC_PARALLEL_PARMARKBITMAP_HPP |
| |
| #include "memory/memRegion.hpp" |
| #include "oops/oop.hpp" |
| #include "utilities/bitMap.hpp" |
| |
| class ParMarkBitMapClosure; |
| class PSVirtualSpace; |
| class ParCompactionManager; |
| |
| 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(ParCompactionManager* cm, 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: |
| size_t live_words_in_range_helper(HeapWord* beg_addr, oop end_obj) const; |
| |
| bool is_live_words_in_range_in_cache(ParCompactionManager* cm, HeapWord* beg_addr) const; |
| size_t live_words_in_range_use_cache(ParCompactionManager* cm, HeapWord* beg_addr, oop end_obj) const; |
| void update_live_words_in_range_cache(ParCompactionManager* cm, HeapWord* beg_addr, oop end_obj, size_t result) const; |
| |
| // 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; |
| BitMapView _beg_bits; |
| BitMapView _end_bits; |
| PSVirtualSpace* _virtual_space; |
| size_t _reserved_byte_size; |
| }; |
| |
| #endif // SHARE_VM_GC_PARALLEL_PARMARKBITMAP_HPP |