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