1 /* 2 * Copyright (c) 2016, 2018, Red Hat, Inc. All rights reserved. 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 only, as 6 * published by the Free Software Foundation. 7 * 8 * This code is distributed in the hope that it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 11 * version 2 for more details (a copy is included in the LICENSE file that 12 * accompanied this code). 13 * 14 * You should have received a copy of the GNU General Public License version 15 * 2 along with this work; if not, write to the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 17 * 18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 19 * or visit www.oracle.com if you need additional information or have any 20 * questions. 21 * 22 */ 23 24 #ifndef SHARE_VM_GC_SHENANDOAH_SHENANDOAHCOLLECTIONSET_HPP 25 #define SHARE_VM_GC_SHENANDOAH_SHENANDOAHCOLLECTIONSET_HPP 26 27 #include "memory/allocation.hpp" 28 #include "gc/shenandoah/shenandoahHeap.hpp" 29 #include "gc/shenandoah/shenandoahHeapRegion.hpp" 30 31 class ShenandoahCollectionSet : public CHeapObj<mtGC> { 32 friend class ShenandoahHeap; 33 private: 34 size_t const _map_size; 35 size_t const _region_size_bytes_shift; 36 jbyte* const _cset_map; 37 // Bias cset map's base address for fast test if an oop is in cset 38 jbyte* const _biased_cset_map; 39 40 ShenandoahHeap* const _heap; 41 42 size_t _garbage; 43 size_t _live_data; 44 size_t _used; 45 size_t _region_count; 46 47 DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t)); 48 volatile jint _current_index; 49 DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0); 50 51 public: 52 ShenandoahCollectionSet(ShenandoahHeap* heap, HeapWord* heap_base); 53 54 // Add region to collection set 55 void add_region(ShenandoahHeapRegion* r); 56 bool add_region_check_for_duplicates(ShenandoahHeapRegion* r); 57 58 // Bring per-region statuses to consistency with this collection. 59 // TODO: This is a transitional interface that bridges the gap between 60 // region statuses and this collection. Should go away after we merge them. 61 void update_region_status(); 62 63 // Remove region from collection set 64 void remove_region(ShenandoahHeapRegion* r); 65 66 // MT version 67 ShenandoahHeapRegion* claim_next(); 68 69 // Single-thread version 70 ShenandoahHeapRegion* next(); 71 72 size_t count() const { return _region_count; } 73 bool is_empty() const { return _region_count == 0; } 74 75 void clear_current_index() { 76 _current_index = 0; 77 } 78 79 inline bool is_in(ShenandoahHeapRegion* r) const; 80 inline bool is_in(size_t region_number) const; 81 inline bool is_in(HeapWord* p) const; 82 83 void print_on(outputStream* out) const; 84 85 size_t used() const { return _used; } 86 size_t live_data() const { return _live_data; } 87 size_t garbage() const { return _garbage; } 88 void clear(); 89 90 private: 91 jbyte* biased_map_address() const { 92 return _biased_cset_map; 93 } 94 }; 95 96 #endif //SHARE_VM_GC_SHENANDOAH_SHENANDOAHCOLLECTIONSET_HPP