1 /* 2 * Copyright (c) 2001, 2016, 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_PARALLELSCAVENGEHEAP_HPP 26 #define SHARE_VM_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP 27 28 #include "gc/parallel/generationSizer.hpp" 29 #include "gc/parallel/objectStartArray.hpp" 30 #include "gc/parallel/psGCAdaptivePolicyCounters.hpp" 31 #include "gc/parallel/psOldGen.hpp" 32 #include "gc/parallel/psYoungGen.hpp" 33 #include "gc/shared/collectedHeap.hpp" 34 #include "gc/shared/collectorPolicy.hpp" 35 #include "gc/shared/gcPolicyCounters.hpp" 36 #include "gc/shared/gcWhen.hpp" 37 #include "gc/shared/strongRootsScope.hpp" 38 #include "memory/metaspace.hpp" 39 #include "utilities/ostream.hpp" 40 41 class AdjoiningGenerations; 42 class GCHeapSummary; 43 class GCTaskManager; 44 class PSAdaptiveSizePolicy; 45 class PSHeapSummary; 46 47 class ParallelScavengeHeap : public CollectedHeap { 48 friend class VMStructs; 49 private: 50 static PSYoungGen* _young_gen; 51 static PSOldGen* _old_gen; 52 53 // Sizing policy for entire heap 54 static PSAdaptiveSizePolicy* _size_policy; 55 static PSGCAdaptivePolicyCounters* _gc_policy_counters; 56 57 GenerationSizer* _collector_policy; 58 59 // Collection of generations that are adjacent in the 60 // space reserved for the heap. 61 AdjoiningGenerations* _gens; 62 unsigned int _death_march_count; 63 64 // The task manager 65 static GCTaskManager* _gc_task_manager; 66 67 void trace_heap(GCWhen::Type when, const GCTracer* tracer); 68 69 protected: 70 static inline size_t total_invocations(); 71 HeapWord* allocate_new_tlab(size_t size); 72 73 inline bool should_alloc_in_eden(size_t size) const; 74 inline void death_march_check(HeapWord* const result, size_t size); 75 HeapWord* mem_allocate_old_gen(size_t size); 76 77 public: 78 ParallelScavengeHeap(GenerationSizer* policy) : 79 CollectedHeap(), _collector_policy(policy), _death_march_count(0) { } 80 81 // For use by VM operations 82 enum CollectionType { 83 Scavenge, 84 MarkSweep 85 }; 86 87 virtual Name kind() const { 88 return CollectedHeap::ParallelScavengeHeap; 89 } 90 91 virtual const char* name() const { 92 return "Parallel"; 93 } 94 95 virtual CollectorPolicy* collector_policy() const { return _collector_policy; } 96 97 static PSYoungGen* young_gen() { return _young_gen; } 98 static PSOldGen* old_gen() { return _old_gen; } 99 100 virtual PSAdaptiveSizePolicy* size_policy() { return _size_policy; } 101 102 static PSGCAdaptivePolicyCounters* gc_policy_counters() { return _gc_policy_counters; } 103 104 static ParallelScavengeHeap* heap(); 105 106 static GCTaskManager* const gc_task_manager() { return _gc_task_manager; } 107 108 AdjoiningGenerations* gens() { return _gens; } 109 110 // Returns JNI_OK on success 111 virtual jint initialize(); 112 113 void post_initialize(); 114 void update_counters(); 115 116 // The alignment used for the various areas 117 size_t space_alignment() { return _collector_policy->space_alignment(); } 118 size_t generation_alignment() { return _collector_policy->gen_alignment(); } 119 120 // Return the (conservative) maximum heap alignment 121 static size_t conservative_max_heap_alignment() { 122 return CollectorPolicy::compute_heap_alignment(); 123 } 124 125 size_t capacity() const; 126 size_t used() const; 127 128 // Return "true" if all generations have reached the 129 // maximal committed limit that they can reach, without a garbage 130 // collection. 131 virtual bool is_maximal_no_gc() const; 132 133 // Return true if the reference points to an object that 134 // can be moved in a partial collection. For currently implemented 135 // generational collectors that means during a collection of 136 // the young gen. 137 virtual bool is_scavengable(oop obj); 138 virtual void register_nmethod(nmethod* nm); 139 virtual void verify_nmethod(nmethod* nmethod); 140 141 size_t max_capacity() const; 142 143 // Whether p is in the allocated part of the heap 144 bool is_in(const void* p) const; 145 146 bool is_in_reserved(const void* p) const; 147 148 bool is_in_young(oop p); // reserved part 149 bool is_in_old(oop p); // reserved part 150 151 // Memory allocation. "gc_time_limit_was_exceeded" will 152 // be set to true if the adaptive size policy determine that 153 // an excessive amount of time is being spent doing collections 154 // and caused a NULL to be returned. If a NULL is not returned, 155 // "gc_time_limit_was_exceeded" has an undefined meaning. 156 HeapWord* mem_allocate(size_t size, bool* gc_overhead_limit_was_exceeded); 157 158 // Allocation attempt(s) during a safepoint. It should never be called 159 // to allocate a new TLAB as this allocation might be satisfied out 160 // of the old generation. 161 HeapWord* failed_mem_allocate(size_t size); 162 163 // Support for System.gc() 164 void collect(GCCause::Cause cause); 165 166 // These also should be called by the vm thread at a safepoint (e.g., from a 167 // VM operation). 168 // 169 // The first collects the young generation only, unless the scavenge fails; it 170 // will then attempt a full gc. The second collects the entire heap; if 171 // maximum_compaction is true, it will compact everything and clear all soft 172 // references. 173 inline void invoke_scavenge(); 174 175 // Perform a full collection 176 virtual void do_full_collection(bool clear_all_soft_refs); 177 178 bool supports_inline_contig_alloc() const { return !UseNUMA; } 179 180 HeapWord* volatile* top_addr() const { return !UseNUMA ? young_gen()->top_addr() : (HeapWord* volatile*)-1; } 181 HeapWord** end_addr() const { return !UseNUMA ? young_gen()->end_addr() : (HeapWord**)-1; } 182 183 void ensure_parsability(bool retire_tlabs); 184 void accumulate_statistics_all_tlabs(); 185 void resize_all_tlabs(); 186 187 bool supports_tlab_allocation() const { return true; } 188 189 size_t tlab_capacity(Thread* thr) const; 190 size_t tlab_used(Thread* thr) const; 191 size_t unsafe_max_tlab_alloc(Thread* thr) const; 192 193 // Can a compiler initialize a new object without store barriers? 194 // This permission only extends from the creation of a new object 195 // via a TLAB up to the first subsequent safepoint. 196 virtual bool can_elide_tlab_store_barriers() const { 197 return true; 198 } 199 200 virtual bool card_mark_must_follow_store() const { 201 return false; 202 } 203 204 // Return true if we don't we need a store barrier for 205 // initializing stores to an object at this address. 206 virtual bool can_elide_initializing_store_barrier(oop new_obj); 207 208 void object_iterate(ObjectClosure* cl); 209 void safe_object_iterate(ObjectClosure* cl) { object_iterate(cl); } 210 211 HeapWord* block_start(const void* addr) const; 212 size_t block_size(const HeapWord* addr) const; 213 bool block_is_obj(const HeapWord* addr) const; 214 215 jlong millis_since_last_gc(); 216 217 void prepare_for_verify(); 218 PSHeapSummary create_ps_heap_summary(); 219 virtual void print_on(outputStream* st) const; 220 virtual void print_on_error(outputStream* st) const; 221 virtual void print_gc_threads_on(outputStream* st) const; 222 virtual void gc_threads_do(ThreadClosure* tc) const; 223 virtual void print_tracing_info() const; 224 225 void verify(VerifyOption option /* ignored */); 226 227 // Resize the young generation. The reserved space for the 228 // generation may be expanded in preparation for the resize. 229 void resize_young_gen(size_t eden_size, size_t survivor_size); 230 231 // Resize the old generation. The reserved space for the 232 // generation may be expanded in preparation for the resize. 233 void resize_old_gen(size_t desired_free_space); 234 235 // Save the tops of the spaces in all generations 236 void record_gen_tops_before_GC() PRODUCT_RETURN; 237 238 // Mangle the unused parts of all spaces in the heap 239 void gen_mangle_unused_area() PRODUCT_RETURN; 240 241 // Call these in sequential code around the processing of strong roots. 242 class ParStrongRootsScope : public MarkScope { 243 public: 244 ParStrongRootsScope(); 245 ~ParStrongRootsScope(); 246 }; 247 }; 248 249 // Simple class for storing info about the heap at the start of GC, to be used 250 // after GC for comparison/printing. 251 class PreGCValues { 252 public: 253 PreGCValues(ParallelScavengeHeap* heap) : 254 _heap_used(heap->used()), 255 _young_gen_used(heap->young_gen()->used_in_bytes()), 256 _old_gen_used(heap->old_gen()->used_in_bytes()), 257 _metadata_used(MetaspaceAux::used_bytes()) { }; 258 259 size_t heap_used() const { return _heap_used; } 260 size_t young_gen_used() const { return _young_gen_used; } 261 size_t old_gen_used() const { return _old_gen_used; } 262 size_t metadata_used() const { return _metadata_used; } 263 264 private: 265 size_t _heap_used; 266 size_t _young_gen_used; 267 size_t _old_gen_used; 268 size_t _metadata_used; 269 }; 270 271 // Class that can be used to print information about the 272 // adaptive size policy at intervals specified by 273 // AdaptiveSizePolicyOutputInterval. Only print information 274 // if an adaptive size policy is in use. 275 class AdaptiveSizePolicyOutput : AllStatic { 276 static bool enabled() { 277 return UseParallelGC && 278 UseAdaptiveSizePolicy && 279 log_is_enabled(Debug, gc, ergo); 280 } 281 public: 282 static void print() { 283 if (enabled()) { 284 ParallelScavengeHeap::heap()->size_policy()->print(); 285 } 286 } 287 288 static void print(AdaptiveSizePolicy* size_policy, uint count) { 289 bool do_print = 290 enabled() && 291 (AdaptiveSizePolicyOutputInterval > 0) && 292 (count % AdaptiveSizePolicyOutputInterval) == 0; 293 294 if (do_print) { 295 size_policy->print(); 296 } 297 } 298 }; 299 300 #endif // SHARE_VM_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP