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