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 37 class PSOldGen : public CHeapObj<mtGC> { 38 friend class VMStructs; 39 friend class PSPromotionManager; // Uses the cas_allocate methods 40 friend class ParallelScavengeHeap; 41 friend class AdjoiningGenerations; 42 43 protected: 44 MemRegion _reserved; // Used for simple containment tests 45 PSVirtualSpace* _virtual_space; // Controls mapping and unmapping of virtual mem 46 ObjectStartArray _start_array; // Keeps track of where objects start in a 512b block 47 MutableSpace* _object_space; // Where all the objects live 48 #if INCLUDE_SERIALGC 49 PSMarkSweepDecorator* _object_mark_sweep; // The mark sweep view of _object_space 50 #endif 51 const char* const _name; // Name of this generation. 52 53 // Performance Counters 54 PSGenerationCounters* _gen_counters; 55 SpaceCounters* _space_counters; 56 57 // Sizing information, in bytes, set in constructor 58 const size_t _init_gen_size; 59 const size_t _min_gen_size; 60 const size_t _max_gen_size; 61 62 // Used when initializing the _name field. 63 static inline const char* select_name(); 64 65 #ifdef ASSERT assert_block_in_covered_region(MemRegion new_memregion)66 void assert_block_in_covered_region(MemRegion new_memregion) { 67 // Explictly capture current covered_region in a local 68 MemRegion covered_region = this->start_array()->covered_region(); 69 assert(covered_region.contains(new_memregion), 70 "new region is not in covered_region [ " PTR_FORMAT ", " PTR_FORMAT " ], " 71 "new region [ " PTR_FORMAT ", " PTR_FORMAT " ], " 72 "object space [ " PTR_FORMAT ", " PTR_FORMAT " ]", 73 p2i(covered_region.start()), 74 p2i(covered_region.end()), 75 p2i(new_memregion.start()), 76 p2i(new_memregion.end()), 77 p2i(this->object_space()->used_region().start()), 78 p2i(this->object_space()->used_region().end())); 79 } 80 #endif 81 allocate_noexpand(size_t word_size)82 HeapWord* allocate_noexpand(size_t word_size) { 83 // We assume the heap lock is held here. 84 assert_locked_or_safepoint(Heap_lock); 85 HeapWord* res = object_space()->allocate(word_size); 86 if (res != NULL) { 87 DEBUG_ONLY(assert_block_in_covered_region(MemRegion(res, word_size))); 88 _start_array.allocate_block(res); 89 } 90 return res; 91 } 92 93 // Support for MT garbage collection. CAS allocation is lower overhead than grabbing 94 // and releasing the heap lock, which is held during gc's anyway. This method is not 95 // safe for use at the same time as allocate_noexpand()! cas_allocate_noexpand(size_t word_size)96 HeapWord* cas_allocate_noexpand(size_t word_size) { 97 assert(SafepointSynchronize::is_at_safepoint(), "Must only be called at safepoint"); 98 HeapWord* res = object_space()->cas_allocate(word_size); 99 if (res != NULL) { 100 DEBUG_ONLY(assert_block_in_covered_region(MemRegion(res, word_size))); 101 _start_array.allocate_block(res); 102 } 103 return res; 104 } 105 106 // Support for MT garbage collection. See above comment. cas_allocate(size_t word_size)107 HeapWord* cas_allocate(size_t word_size) { 108 HeapWord* res = cas_allocate_noexpand(word_size); 109 return (res == NULL) ? expand_and_cas_allocate(word_size) : res; 110 } 111 112 HeapWord* expand_and_allocate(size_t word_size); 113 HeapWord* expand_and_cas_allocate(size_t word_size); 114 void expand(size_t bytes); 115 bool expand_by(size_t bytes); 116 bool expand_to_reserved(); 117 118 void shrink(size_t bytes); 119 120 void post_resize(); 121 122 public: 123 // Initialize the generation. 124 PSOldGen(ReservedSpace rs, size_t alignment, 125 size_t initial_size, size_t min_size, size_t max_size, 126 const char* perf_data_name, int level); 127 128 PSOldGen(size_t initial_size, size_t min_size, size_t max_size, 129 const char* perf_data_name, int level); 130 131 virtual void initialize(ReservedSpace rs, size_t alignment, 132 const char* perf_data_name, int level); 133 void initialize_virtual_space(ReservedSpace rs, size_t alignment); 134 virtual void initialize_work(const char* perf_data_name, int level); 135 virtual void initialize_performance_counters(const char* perf_data_name, int level); 136 reserved() const137 MemRegion reserved() const { return _reserved; } max_gen_size()138 virtual size_t max_gen_size() { return _max_gen_size; } min_gen_size()139 size_t min_gen_size() { return _min_gen_size; } 140 141 // Returns limit on the maximum size of the generation. This 142 // is the same as _max_gen_size for PSOldGen but need not be 143 // for a derived class. 144 virtual size_t gen_size_limit(); 145 is_in(const void * p) const146 bool is_in(const void* p) const { 147 return _virtual_space->contains((void *)p); 148 } 149 is_in_reserved(const void * p) const150 bool is_in_reserved(const void* p) const { 151 return reserved().contains(p); 152 } 153 object_space() const154 MutableSpace* object_space() const { return _object_space; } 155 #if INCLUDE_SERIALGC object_mark_sweep() const156 PSMarkSweepDecorator* object_mark_sweep() const { return _object_mark_sweep; } 157 #endif start_array()158 ObjectStartArray* start_array() { return &_start_array; } virtual_space() const159 PSVirtualSpace* virtual_space() const { return _virtual_space;} 160 161 // Has the generation been successfully allocated? 162 bool is_allocated(); 163 164 #if INCLUDE_SERIALGC 165 // MarkSweep methods 166 virtual void precompact(); 167 void adjust_pointers(); 168 void compact(); 169 #endif 170 171 // Size info capacity_in_bytes() const172 size_t capacity_in_bytes() const { return object_space()->capacity_in_bytes(); } used_in_bytes() const173 size_t used_in_bytes() const { return object_space()->used_in_bytes(); } free_in_bytes() const174 size_t free_in_bytes() const { return object_space()->free_in_bytes(); } 175 capacity_in_words() const176 size_t capacity_in_words() const { return object_space()->capacity_in_words(); } used_in_words() const177 size_t used_in_words() const { return object_space()->used_in_words(); } free_in_words() const178 size_t free_in_words() const { return object_space()->free_in_words(); } 179 180 // Includes uncommitted memory 181 size_t contiguous_available() const; 182 is_maximal_no_gc() const183 bool is_maximal_no_gc() const { 184 return virtual_space()->uncommitted_size() == 0; 185 } 186 187 // Calculating new sizes 188 void resize(size_t desired_free_space); 189 190 // Allocation. We report all successful allocations to the size policy 191 // Note that the perm gen does not use this method, and should not! 192 HeapWord* allocate(size_t word_size); 193 194 // Iteration. oop_iterate(OopIterateClosure * cl)195 void oop_iterate(OopIterateClosure* cl) { object_space()->oop_iterate(cl); } object_iterate(ObjectClosure * cl)196 void object_iterate(ObjectClosure* cl) { object_space()->object_iterate(cl); } 197 198 // Debugging - do not use for time critical operations 199 virtual void print() const; 200 virtual void print_on(outputStream* st) const; 201 void print_used_change(size_t prev_used) const; 202 203 void verify(); 204 void verify_object_start_array(); 205 206 // These should not used 207 virtual void reset_after_change(); 208 209 // These should not used 210 virtual size_t available_for_expansion(); 211 virtual size_t available_for_contraction(); 212 213 void space_invariants() PRODUCT_RETURN; 214 215 // Performance Counter support 216 void update_counters(); 217 218 // Printing support name() const219 virtual const char* name() const { return _name; } 220 221 // Debugging support 222 // Save the tops of all spaces for later use during mangling. 223 void record_spaces_top() PRODUCT_RETURN; 224 }; 225 226 #endif // SHARE_VM_GC_PARALLEL_PSOLDGEN_HPP 227