1 /* 2 * Copyright (c) 2001, 2015, 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_PARALLEL_PSOLDGEN_HPP 26 #define SHARE_VM_GC_PARALLEL_PSOLDGEN_HPP 27 28 #include "gc/parallel/mutableSpace.hpp" 29 #include "gc/parallel/objectStartArray.hpp" 30 #include "gc/parallel/psGenerationCounters.hpp" 31 #include "gc/parallel/psVirtualspace.hpp" 32 #include "gc/parallel/psFileBackedVirtualspace.hpp" 33 #include "gc/parallel/spaceCounters.hpp" 34 #include "runtime/safepoint.hpp" 35 36 class PSMarkSweepDecorator; 37 38 class PSOldGen : public CHeapObj<mtGC> { 39 friend class VMStructs; 40 friend class PSPromotionManager; // Uses the cas_allocate methods 41 friend class ParallelScavengeHeap; 42 friend class AdjoiningGenerations; 43 44 protected: 45 MemRegion _reserved; // Used for simple containment tests 46 PSVirtualSpace* _virtual_space; // Controls mapping and unmapping of virtual mem 47 ObjectStartArray _start_array; // Keeps track of where objects start in a 512b block 48 MutableSpace* _object_space; // Where all the objects live 49 #if INCLUDE_SERIALGC 50 PSMarkSweepDecorator* _object_mark_sweep; // The mark sweep view of _object_space 51 #endif 52 const char* const _name; // Name of this generation. 53 54 // Performance Counters 55 PSGenerationCounters* _gen_counters; 56 SpaceCounters* _space_counters; 57 58 // Sizing information, in bytes, set in constructor 59 const size_t _init_gen_size; 60 const size_t _min_gen_size; 61 const size_t _max_gen_size; 62 63 // Used when initializing the _name field. 64 static inline const char* select_name(); 65 66 #ifdef ASSERT 67 void assert_block_in_covered_region(MemRegion new_memregion) { 68 // Explictly capture current covered_region in a local 69 MemRegion covered_region = this->start_array()->covered_region(); 70 assert(covered_region.contains(new_memregion), 71 "new region is not in covered_region [ " PTR_FORMAT ", " PTR_FORMAT " ], " 72 "new region [ " PTR_FORMAT ", " PTR_FORMAT " ], " 73 "object space [ " PTR_FORMAT ", " PTR_FORMAT " ]", 74 p2i(covered_region.start()), 75 p2i(covered_region.end()), 76 p2i(new_memregion.start()), 77 p2i(new_memregion.end()), 78 p2i(this->object_space()->used_region().start()), 79 p2i(this->object_space()->used_region().end())); 80 } 81 #endif 82 83 HeapWord* allocate_noexpand(size_t word_size) { 84 // We assume the heap lock is held here. 85 assert_locked_or_safepoint(Heap_lock); 86 HeapWord* res = object_space()->allocate(word_size); 87 if (res != NULL) { 88 DEBUG_ONLY(assert_block_in_covered_region(MemRegion(res, word_size))); 89 _start_array.allocate_block(res); 90 } 91 return res; 92 } 93 94 // Support for MT garbage collection. CAS allocation is lower overhead than grabbing 95 // and releasing the heap lock, which is held during gc's anyway. This method is not 96 // safe for use at the same time as allocate_noexpand()! 97 HeapWord* cas_allocate_noexpand(size_t word_size) { 98 assert(SafepointSynchronize::is_at_safepoint(), "Must only be called at safepoint"); 99 HeapWord* res = object_space()->cas_allocate(word_size); 100 if (res != NULL) { 101 DEBUG_ONLY(assert_block_in_covered_region(MemRegion(res, word_size))); 102 _start_array.allocate_block(res); 103 } 104 return res; 105 } 106 107 // Support for MT garbage collection. See above comment. 108 HeapWord* cas_allocate(size_t word_size) { 109 HeapWord* res = cas_allocate_noexpand(word_size); 110 return (res == NULL) ? expand_and_cas_allocate(word_size) : res; 111 } 112 113 HeapWord* expand_and_allocate(size_t word_size); 114 HeapWord* expand_and_cas_allocate(size_t word_size); 115 void expand(size_t bytes); 116 bool expand_by(size_t bytes); 117 bool expand_to_reserved(); 118 119 void shrink(size_t bytes); 120 121 void post_resize(); 122 123 public: 124 // Initialize the generation. 125 PSOldGen(ReservedSpace rs, size_t alignment, 126 size_t initial_size, size_t min_size, size_t max_size, 127 const char* perf_data_name, int level); 128 129 PSOldGen(size_t initial_size, size_t min_size, size_t max_size, 130 const char* perf_data_name, int level); 131 132 virtual void initialize(ReservedSpace rs, size_t alignment, 133 const char* perf_data_name, int level); 134 void initialize_virtual_space(ReservedSpace rs, size_t alignment); 135 virtual void initialize_work(const char* perf_data_name, int level); 136 virtual void initialize_performance_counters(const char* perf_data_name, int level); 137 138 MemRegion reserved() const { return _reserved; } 139 virtual size_t max_gen_size() { return _max_gen_size; } 140 size_t min_gen_size() { return _min_gen_size; } 141 142 // Returns limit on the maximum size of the generation. This 143 // is the same as _max_gen_size for PSOldGen but need not be 144 // for a derived class. 145 virtual size_t gen_size_limit(); 146 147 bool is_in(const void* p) const { 148 return _virtual_space->contains((void *)p); 149 } 150 151 bool is_in_reserved(const void* p) const { 152 return reserved().contains(p); 153 } 154 155 MutableSpace* object_space() const { return _object_space; } 156 #if INCLUDE_SERIALGC 157 PSMarkSweepDecorator* object_mark_sweep() const { return _object_mark_sweep; } 158 #endif 159 ObjectStartArray* start_array() { return &_start_array; } 160 PSVirtualSpace* virtual_space() const { return _virtual_space;} 161 162 // Has the generation been successfully allocated? 163 bool is_allocated(); 164 165 #if INCLUDE_SERIALGC 166 // MarkSweep methods 167 virtual void precompact(); 168 void adjust_pointers(); 169 void compact(); 170 #endif 171 172 // Size info 173 size_t capacity_in_bytes() const { return object_space()->capacity_in_bytes(); } 174 size_t used_in_bytes() const { return object_space()->used_in_bytes(); } 175 size_t free_in_bytes() const { return object_space()->free_in_bytes(); } 176 177 size_t capacity_in_words() const { return object_space()->capacity_in_words(); } 178 size_t used_in_words() const { return object_space()->used_in_words(); } 179 size_t free_in_words() const { return object_space()->free_in_words(); } 180 181 // Includes uncommitted memory 182 size_t contiguous_available() const; 183 184 bool is_maximal_no_gc() const { 185 return virtual_space()->uncommitted_size() == 0; 186 } 187 188 // Calculating new sizes 189 void resize(size_t desired_free_space); 190 191 // Allocation. We report all successful allocations to the size policy 192 // Note that the perm gen does not use this method, and should not! 193 HeapWord* allocate(size_t word_size); 194 195 // Iteration. 196 void oop_iterate(OopIterateClosure* cl) { object_space()->oop_iterate(cl); } 197 void object_iterate(ObjectClosure* cl) { object_space()->object_iterate(cl); } 198 199 // Debugging - do not use for time critical operations 200 virtual void print() const; 201 virtual void print_on(outputStream* st) const; 202 void print_used_change(size_t prev_used) const; 203 204 void verify(); 205 void verify_object_start_array(); 206 207 // These should not used 208 virtual void reset_after_change(); 209 210 // These should not used 211 virtual size_t available_for_expansion(); 212 virtual size_t available_for_contraction(); 213 214 void space_invariants() PRODUCT_RETURN; 215 216 // Performance Counter support 217 void update_counters(); 218 219 // Printing support 220 virtual const char* name() const { return _name; } 221 222 // Debugging support 223 // Save the tops of all spaces for later use during mangling. 224 void record_spaces_top() PRODUCT_RETURN; 225 }; 226 227 #endif // SHARE_VM_GC_PARALLEL_PSOLDGEN_HPP