--- /dev/null 2017-07-10 09:41:02.918782235 +0200 +++ new/src/share/vm/gc/g1/g1ConcurrentMarkBitMap.hpp 2017-07-20 16:26:00.104457659 +0200 @@ -0,0 +1,126 @@ +/* + * Copyright (c) 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 + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#ifndef SHARE_VM_GC_G1_G1CONCURRENTMARKBITMAP_HPP +#define SHARE_VM_GC_G1_G1CONCURRENTMARKBITMAP_HPP + +#include "gc/g1/g1RegionToSpaceMapper.hpp" +#include "memory/allocation.hpp" +#include "memory/memRegion.hpp" +#include "utilities/bitMap.hpp" +#include "utilities/globalDefinitions.hpp" +#include "utilities/macros.hpp" + +class G1CMBitMap; +class G1CMTask; +class G1ConcurrentMark; + +// Closure for iteration over bitmaps +class G1CMBitMapClosure VALUE_OBJ_CLASS_SPEC { +private: + G1ConcurrentMark* const _cm; + G1CMTask* const _task; +public: + G1CMBitMapClosure(G1CMTask *task, G1ConcurrentMark* cm) : _task(task), _cm(cm) { } + + bool do_addr(HeapWord* const addr); +}; + +class G1CMBitMapMappingChangedListener : public G1MappingChangedListener { + private: + G1CMBitMap* _bm; + public: + G1CMBitMapMappingChangedListener() : _bm(NULL) {} + + void set_bitmap(G1CMBitMap* bm) { _bm = bm; } + + virtual void on_commit(uint start_idx, size_t num_regions, bool zero_filled); +}; + +// A generic mark bitmap for concurrent marking. This is essentially a wrapper +// around the BitMap class that is based on HeapWords, with one bit per (1 << _shifter) HeapWords. +class G1CMBitMap VALUE_OBJ_CLASS_SPEC { +private: + MemRegion _covered; // The heap area covered by this bitmap. + + const int _shifter; // Shift amount from heap index to bit index in the bitmap. + + BitMapView _bm; // The actual bitmap. + + G1CMBitMapMappingChangedListener _listener; + + inline void check_mark(HeapWord* addr) NOT_DEBUG_RETURN; + + // Convert from bit offset to address. + HeapWord* offset_to_addr(size_t offset) const { + return _covered.start() + (offset << _shifter); + } + // Convert from address to bit offset. + size_t addr_to_offset(const HeapWord* addr) const { + return pointer_delta(addr, _covered.start()) >> _shifter; + } +public: + static size_t compute_size(size_t heap_size); + // Returns the amount of bytes on the heap between two marks in the bitmap. + static size_t mark_distance(); + // Returns how many bytes (or bits) of the heap a single byte (or bit) of the + // mark bitmap corresponds to. This is the same as the mark distance above. + static size_t heap_map_factor() { + return mark_distance(); + } + + G1CMBitMap() : _covered(), _bm(), _shifter(LogMinObjAlignment), _listener() { _listener.set_bitmap(this); } + + // Initializes the underlying BitMap to cover the given area. + void initialize(MemRegion heap, G1RegionToSpaceMapper* storage); + + // read marks + bool is_marked(HeapWord* addr) const { + assert(_covered.contains(addr), "Address " PTR_FORMAT " is outside underlying space from " PTR_FORMAT " to " PTR_FORMAT, p2i(addr), p2i(_covered.start()), p2i(_covered.end())); + return _bm.at(addr_to_offset(addr)); + } + + // Apply the closure to the addresses that correspond to marked bits in the bitmap. + inline bool iterate(G1CMBitMapClosure* cl, MemRegion mr); + + // Return the address corresponding to the next marked bit at or after + // "addr", and before "limit", if "limit" is non-NULL. If there is no + // such bit, returns "limit" if that is non-NULL, or else "endWord()". + inline HeapWord* get_next_marked_addr(const HeapWord* addr, + const HeapWord* limit) const; + + // The argument addr should be the start address of a valid object + inline HeapWord* addr_after_obj(HeapWord* addr); + + void print_on_error(outputStream* st, const char* prefix) const; + + // Write marks. + inline void mark(HeapWord* addr); + inline void clear(HeapWord* addr); + inline bool par_mark(HeapWord* addr); + + void clear_range(MemRegion mr); +}; + +#endif // SHARE_VM_GC_G1_G1CONCURRENTMARKBITMAP_HPP