1 /* 2 * Copyright (c) 2013, 2015, Red Hat, Inc. and/or its affiliates. 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_SHENANDOAHHEAPREGION_HPP 25 #define SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEAPREGION_HPP 26 27 #include "gc/shared/space.hpp" 28 #include "memory/universe.hpp" 29 #include "utilities/sizes.hpp" 30 31 class ShenandoahHeapRegion : public ContiguousSpace { 32 private: 33 static const size_t MIN_REGION_SIZE = 256*K; 34 static const size_t MIN_NUM_REGIONS = 10; 35 36 static Monitor _mem_protect_lock; 37 38 public: 39 static size_t RegionSizeBytes; 40 static size_t RegionSizeShift; 41 42 private: 43 ShenandoahHeap* _heap; 44 size_t _region_number; 45 volatile jint _live_data; 46 MemRegion reserved; 47 48 bool _humongous_start; 49 bool _humongous_continuation; 50 51 bool _recycled; 52 53 HeapWord* _new_top; 54 55 volatile jint _critical_pins; 56 57 #ifdef ASSERT 58 int _mem_protection_level; 59 #endif 60 61 public: 62 ShenandoahHeapRegion(ShenandoahHeap* heap, HeapWord* start, size_t regionSize, size_t index); 63 64 static void setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size); 65 66 size_t region_number() const; 67 68 // Allocation (return NULL if full) 69 inline HeapWord* allocate(size_t word_size); 70 71 // Roll back the previous allocation of an object with specified size. 72 // Returns TRUE when successful, FALSE if not successful or not supported. 73 bool rollback_allocation(uint size); 74 75 void clear_live_data(); 76 void set_live_data(size_t s); 77 inline void increase_live_data_words(jint s); 78 79 void set_recently_allocated(bool value); 80 bool is_recently_allocated() const; 81 82 bool has_live() const; 83 size_t get_live_data_bytes() const; 84 size_t get_live_data_words() const; 85 86 void print_on(outputStream* st) const; 87 88 size_t garbage() const; 89 90 void recycle(); 91 92 void object_iterate_interruptible(ObjectClosure* blk, bool allow_cancel); 93 94 HeapWord* object_iterate_careful(ObjectClosureCareful* cl); 95 96 HeapWord* block_start_const(const void* p) const; 97 98 // Just before GC we need to fill the current region. 99 void fill_region(); 100 101 bool in_collection_set() const; 102 103 void set_in_collection_set(bool b); 104 105 void set_humongous_start(bool start); 106 void set_humongous_continuation(bool continuation); 107 108 bool is_humongous() const; 109 bool is_humongous_start() const; 110 bool is_humongous_continuation() const; 111 112 #ifdef ASSERT 113 void memProtectionOn(); 114 void memProtectionOff(); 115 #endif 116 117 // The following are for humongous regions. We need to save the 118 markOop saved_mark_word; 119 void save_mark_word(oop obj) {saved_mark_word = obj->mark();} 120 markOop mark_word() {return saved_mark_word;} 121 122 virtual CompactibleSpace* next_compaction_space() const; 123 124 // Override for scan_and_forward support. 125 void prepare_for_compaction(CompactPoint* cp); 126 void adjust_pointers(); 127 void compact(); 128 129 void set_new_top(HeapWord* new_top) { _new_top = new_top; } 130 HeapWord* new_top() const { return _new_top; } 131 132 void pin(); 133 void unpin(); 134 135 bool is_pinned(); 136 137 }; 138 139 #endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEAPREGION_HPP