1 /* 2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 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_IMPLEMENTATION_G1_G1ALLOCATOR_HPP 26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1ALLOCATOR_HPP 27 28 #include "gc_implementation/g1/g1AllocationContext.hpp" 29 #include "gc_implementation/g1/g1AllocRegion.hpp" 30 #include "gc_implementation/shared/parGCAllocBuffer.hpp" 31 32 enum GCAllocPurpose { 33 GCAllocForTenured, 34 GCAllocForSurvived, 35 GCAllocPurposeCount 36 }; 37 38 // Base class for G1 allocators. 39 class G1Allocator : public CHeapObj<mtGC> { 40 friend class VMStructs; 41 protected: 42 G1CollectedHeap* _g1h; 43 44 // Outside of GC pauses, the number of bytes used in all regions other 45 // than the current allocation region. 46 size_t _summary_bytes_used; 47 48 public: 49 G1Allocator(G1CollectedHeap* heap) : 50 _g1h(heap), _summary_bytes_used(0) { } 51 52 static G1Allocator* create_allocator(G1CollectedHeap* g1h); 53 54 virtual void init_mutator_alloc_region() = 0; 55 virtual void release_mutator_alloc_region() = 0; 56 57 virtual void init_gc_alloc_regions(EvacuationInfo& evacuation_info) = 0; 58 virtual void release_gc_alloc_regions(uint no_of_gc_workers, EvacuationInfo& evacuation_info) = 0; 59 virtual void abandon_gc_alloc_regions() = 0; 60 61 virtual MutatorAllocRegion* mutator_alloc_region(AllocationContext_t context) = 0; 62 virtual SurvivorGCAllocRegion* survivor_gc_alloc_region(AllocationContext_t context) = 0; 63 virtual OldGCAllocRegion* old_gc_alloc_region(AllocationContext_t context) = 0; 64 virtual size_t used() = 0; 65 virtual bool is_retained_old_region(HeapRegion* hr) = 0; 66 67 void reuse_retained_old_region(EvacuationInfo& evacuation_info, 68 OldGCAllocRegion* old, 69 HeapRegion** retained); 70 71 size_t used_unlocked() const { 72 return _summary_bytes_used; 73 } 74 75 void increase_used(size_t bytes) { 76 _summary_bytes_used += bytes; 77 } 78 79 void decrease_used(size_t bytes) { 80 assert(_summary_bytes_used >= bytes, 81 err_msg("invariant: _summary_bytes_used: "SIZE_FORMAT" should be >= bytes: "SIZE_FORMAT, 82 _summary_bytes_used, bytes)); 83 _summary_bytes_used -= bytes; 84 } 85 86 void set_used(size_t bytes) { 87 _summary_bytes_used = bytes; 88 } 89 90 virtual HeapRegion* new_heap_region(uint hrs_index, 91 G1BlockOffsetSharedArray* sharedOffsetArray, 92 MemRegion mr) { 93 return new HeapRegion(hrs_index, sharedOffsetArray, mr); 94 } 95 }; 96 97 // The default allocator for G1. 98 class G1DefaultAllocator : public G1Allocator { 99 protected: 100 // Alloc region used to satisfy mutator allocation requests. 101 MutatorAllocRegion _mutator_alloc_region; 102 103 // Alloc region used to satisfy allocation requests by the GC for 104 // survivor objects. 105 SurvivorGCAllocRegion _survivor_gc_alloc_region; 106 107 // Alloc region used to satisfy allocation requests by the GC for 108 // old objects. 109 OldGCAllocRegion _old_gc_alloc_region; 110 111 HeapRegion* _retained_old_gc_alloc_region; 112 public: 113 G1DefaultAllocator(G1CollectedHeap* heap) : G1Allocator(heap), _retained_old_gc_alloc_region(NULL) { } 114 115 virtual void init_mutator_alloc_region(); 116 virtual void release_mutator_alloc_region(); 117 118 virtual void init_gc_alloc_regions(EvacuationInfo& evacuation_info); 119 virtual void release_gc_alloc_regions(uint no_of_gc_workers, EvacuationInfo& evacuation_info); 120 virtual void abandon_gc_alloc_regions(); 121 122 virtual bool is_retained_old_region(HeapRegion* hr) { 123 return _retained_old_gc_alloc_region == hr; 124 } 125 126 virtual MutatorAllocRegion* mutator_alloc_region(AllocationContext_t context) { 127 return &_mutator_alloc_region; 128 } 129 130 virtual SurvivorGCAllocRegion* survivor_gc_alloc_region(AllocationContext_t context) { 131 return &_survivor_gc_alloc_region; 132 } 133 134 virtual OldGCAllocRegion* old_gc_alloc_region(AllocationContext_t context) { 135 return &_old_gc_alloc_region; 136 } 137 138 virtual size_t used() { 139 assert(Heap_lock->owner() != NULL, 140 "Should be owned on this thread's behalf."); 141 size_t result = _summary_bytes_used; 142 143 // Read only once in case it is set to NULL concurrently 144 HeapRegion* hr = mutator_alloc_region(AllocationContext::current())->get(); 145 if (hr != NULL) { 146 result += hr->used(); 147 } 148 return result; 149 } 150 }; 151 152 class G1ParGCAllocBuffer: public ParGCAllocBuffer { 153 private: 154 bool _retired; 155 156 public: 157 G1ParGCAllocBuffer(size_t gclab_word_size); 158 virtual ~G1ParGCAllocBuffer() { 159 guarantee(_retired, "Allocation buffer has not been retired"); 160 } 161 162 virtual void set_buf(HeapWord* buf) { 163 ParGCAllocBuffer::set_buf(buf); 164 _retired = false; 165 } 166 167 virtual void retire(bool end_of_gc, bool retain) { 168 if (_retired) { 169 return; 170 } 171 ParGCAllocBuffer::retire(end_of_gc, retain); 172 _retired = true; 173 } 174 }; 175 176 class G1ParGCAllocator : public CHeapObj<mtGC> { 177 friend class G1ParScanThreadState; 178 protected: 179 G1CollectedHeap* _g1h; 180 181 size_t _alloc_buffer_waste; 182 size_t _undo_waste; 183 184 void add_to_alloc_buffer_waste(size_t waste) { _alloc_buffer_waste += waste; } 185 void add_to_undo_waste(size_t waste) { _undo_waste += waste; } 186 187 HeapWord* allocate_slow(GCAllocPurpose purpose, size_t word_sz, AllocationContext_t context); 188 189 virtual void retire_alloc_buffers() = 0; 190 virtual G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose, AllocationContext_t context) = 0; 191 192 public: 193 G1ParGCAllocator(G1CollectedHeap* g1h) : 194 _g1h(g1h), _alloc_buffer_waste(0), _undo_waste(0) { 195 } 196 197 static G1ParGCAllocator* create_allocator(G1CollectedHeap* g1h); 198 199 size_t alloc_buffer_waste() { return _alloc_buffer_waste; } 200 size_t undo_waste() {return _undo_waste; } 201 202 HeapWord* allocate(GCAllocPurpose purpose, size_t word_sz, AllocationContext_t context) { 203 HeapWord* obj = NULL; 204 if (purpose == GCAllocForSurvived) { 205 obj = alloc_buffer(purpose, context)->allocate_aligned(word_sz, SurvivorAlignmentInBytes); 206 } else { 207 obj = alloc_buffer(purpose, context)->allocate(word_sz); 208 } 209 if (obj != NULL) { 210 return obj; 211 } 212 return allocate_slow(purpose, word_sz, context); 213 } 214 215 void undo_allocation(GCAllocPurpose purpose, HeapWord* obj, size_t word_sz, AllocationContext_t context) { 216 if (alloc_buffer(purpose, context)->contains(obj)) { 217 assert(alloc_buffer(purpose, context)->contains(obj + word_sz - 1), 218 "should contain whole object"); 219 alloc_buffer(purpose, context)->undo_allocation(obj, word_sz); 220 } else { 221 CollectedHeap::fill_with_object(obj, word_sz); 222 add_to_undo_waste(word_sz); 223 } 224 } 225 }; 226 227 class G1DefaultParGCAllocator : public G1ParGCAllocator { 228 G1ParGCAllocBuffer _surviving_alloc_buffer; 229 G1ParGCAllocBuffer _tenured_alloc_buffer; 230 G1ParGCAllocBuffer* _alloc_buffers[GCAllocPurposeCount]; 231 232 public: 233 G1DefaultParGCAllocator(G1CollectedHeap* g1h); 234 235 virtual G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose, AllocationContext_t context) { 236 return _alloc_buffers[purpose]; 237 } 238 239 virtual void retire_alloc_buffers() ; 240 }; 241 242 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1ALLOCATOR_HPP