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_SHENANDOAHFREESET_HPP 25 #define SHARE_VM_GC_SHENANDOAH_SHENANDOAHFREESET_HPP 26 27 #include "gc/shenandoah/shenandoahHeapRegionSet.hpp" 28 #include "gc/shenandoah/shenandoahHeap.hpp" 29 30 class ShenandoahFreeSet : public CHeapObj<mtGC> { 31 private: 32 ShenandoahHeap* const _heap; 33 CHeapBitMap _mutator_free_bitmap; 34 CHeapBitMap _collector_free_bitmap; 35 size_t _max; 36 37 // Left-most and right-most region indexes. There are no free regions outside 38 // of [left-most; right-most] index intervals 39 size_t _mutator_leftmost, _mutator_rightmost; 40 size_t _collector_leftmost, _collector_rightmost; 41 42 size_t _capacity; 43 size_t _used; 44 45 void assert_bounds() const PRODUCT_RETURN; 46 void assert_heaplock_owned_by_current_thread() const PRODUCT_RETURN; 47 void assert_heaplock_not_owned_by_current_thread() const PRODUCT_RETURN; 48 49 bool is_mutator_free(size_t idx) const; 50 bool is_collector_free(size_t idx) const; 51 52 HeapWord* try_allocate_in(ShenandoahHeapRegion* region, ShenandoahAllocRequest& req, bool& in_new_region); 53 HeapWord* allocate_single(ShenandoahAllocRequest& req, bool& in_new_region); 54 HeapWord* allocate_contiguous(ShenandoahAllocRequest& req); 55 56 void flip_to_gc(ShenandoahHeapRegion* r); 57 58 void recompute_bounds(); 59 void adjust_bounds(); 60 bool touches_bounds(size_t num) const; 61 62 void increase_used(size_t amount); 63 void clear_internal(); 64 65 size_t collector_count() const { return _collector_free_bitmap.count_one_bits(); } 66 size_t mutator_count() const { return _mutator_free_bitmap.count_one_bits(); } 67 68 void try_recycle_trashed(ShenandoahHeapRegion *r); 69 70 bool is_empty_or_trash(ShenandoahHeapRegion *r); 71 size_t alloc_capacity(ShenandoahHeapRegion *r); 72 bool has_no_alloc_capacity(ShenandoahHeapRegion *r); 73 74 public: 75 ShenandoahFreeSet(ShenandoahHeap* heap, size_t max_regions); 76 77 void clear(); 78 void rebuild(); 79 80 void recycle_trash(); 81 82 void log_status(); 83 84 size_t capacity() const { return _capacity; } 85 size_t used() const { return _used; } 86 size_t available() const { 87 assert(_used <= _capacity, "must use less than capacity"); 88 return _capacity - _used; 89 } 90 91 HeapWord* allocate(ShenandoahAllocRequest& req, bool& in_new_region); 92 size_t unsafe_peek_free() const; 93 94 void print_on(outputStream* out) const; 95 }; 96 97 #endif //SHARE_VM_GC_SHENANDOAH_SHENANDOAHFREESET_HPP