1 2 /* 3 * Copyright (c) 2016, 2018, Red Hat, Inc. All rights reserved. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_GC_SHENANDOAH_SHENANDOAHFREESET_HPP 26 #define SHARE_VM_GC_SHENANDOAH_SHENANDOAHFREESET_HPP 27 28 #include "gc/shenandoah/shenandoahHeapRegionSet.hpp" 29 #include "gc/shenandoah/shenandoahHeap.hpp" 30 31 class ShenandoahFreeSet : public CHeapObj<mtGC> { 32 private: 33 ShenandoahHeap* const _heap; 34 CHeapBitMap _mutator_free_bitmap; 35 CHeapBitMap _collector_free_bitmap; 36 size_t _max; 37 38 // Left-most and right-most region indexes. There are no free regions outside 39 // of [left-most; right-most] index intervals 40 size_t _mutator_leftmost, _mutator_rightmost; 41 size_t _collector_leftmost, _collector_rightmost; 42 43 size_t _capacity; 44 size_t _used; 45 46 void assert_bounds() const NOT_DEBUG_RETURN; 47 void assert_heaplock_owned_by_current_thread() const NOT_DEBUG_RETURN; 48 void assert_heaplock_not_owned_by_current_thread() const NOT_DEBUG_RETURN; 49 50 bool is_mutator_free(size_t idx) const; 51 bool is_collector_free(size_t idx) const; 52 53 HeapWord* try_allocate_in(ShenandoahHeapRegion* region, ShenandoahAllocRequest& req, bool& in_new_region); 54 HeapWord* allocate_single(ShenandoahAllocRequest& req, bool& in_new_region); 55 HeapWord* allocate_contiguous(ShenandoahAllocRequest& req); 56 57 void flip_to_gc(ShenandoahHeapRegion* r); 58 59 void recompute_bounds(); 60 void adjust_bounds(); 61 bool touches_bounds(size_t num) const; 62 63 void increase_used(size_t amount); 64 void clear_internal(); 65 66 size_t collector_count() const { return _collector_free_bitmap.count_one_bits(); } 67 size_t mutator_count() const { return _mutator_free_bitmap.count_one_bits(); } 68 69 void try_recycle_trashed(ShenandoahHeapRegion *r); 70 71 bool is_empty_or_trash(ShenandoahHeapRegion *r); 72 size_t alloc_capacity(ShenandoahHeapRegion *r); 73 bool has_no_alloc_capacity(ShenandoahHeapRegion *r); 74 75 public: 76 ShenandoahFreeSet(ShenandoahHeap* heap, size_t max_regions); 77 78 void clear(); 79 void rebuild(); 80 81 void recycle_trash(); 82 83 void log_status(); 84 85 size_t capacity() const { return _capacity; } 86 size_t used() const { return _used; } 87 size_t available() const { 88 assert(_used <= _capacity, "must use less than capacity"); 89 return _capacity - _used; 90 } 91 92 HeapWord* allocate(ShenandoahAllocRequest& req, bool& in_new_region); 93 size_t unsafe_peek_free() const; 94 95 void print_on(outputStream* out) const; 96 }; 97 98 #endif //SHARE_VM_GC_SHENANDOAH_SHENANDOAHFREESET_HPP