1 /* 2 * Copyright (c) 2002, 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_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONMANAGER_INLINE_HPP 26 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONMANAGER_INLINE_HPP 27 28 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp" 29 #include "gc_implementation/parallelScavenge/psOldGen.hpp" 30 #include "gc_implementation/parallelScavenge/psPromotionManager.hpp" 31 #include "gc_implementation/parallelScavenge/psPromotionLAB.inline.hpp" 32 #include "gc_implementation/parallelScavenge/psScavenge.hpp" 33 #include "oops/oop.inline.hpp" 34 #include "utilities/taskqueue.inline.hpp" 35 36 inline PSPromotionManager* PSPromotionManager::manager_array(int index) { 37 assert(_manager_array != NULL, "access of NULL manager_array"); 38 assert(index >= 0 && index <= (int)ParallelGCThreads, "out of range manager_array access"); 39 return &_manager_array[index]; 40 } 41 42 template <class T> 43 inline void PSPromotionManager::push_depth(T* p) { 44 claimed_stack_depth()->push(p); 45 } 46 47 template <class T> 48 inline void PSPromotionManager::claim_or_forward_internal_depth(T* p) { 49 if (p != NULL) { // XXX: error if p != NULL here 50 oop o = oopDesc::load_decode_heap_oop_not_null(p); 51 if (o->is_forwarded()) { 52 o = o->forwardee(); 53 // Card mark 54 if (PSScavenge::is_obj_in_young(o)) { 55 PSScavenge::card_table()->inline_write_ref_field_gc(p, o); 56 } 57 oopDesc::encode_store_heap_oop_not_null(p, o); 58 } else { 59 push_depth(p); 60 } 61 } 62 } 63 64 template <class T> 65 inline void PSPromotionManager::claim_or_forward_depth(T* p) { 66 assert(should_scavenge(p, true), "revisiting object?"); 67 assert(ParallelScavengeHeap::heap()->is_in(p), "pointer outside heap"); 68 69 claim_or_forward_internal_depth(p); 70 } 71 72 inline void PSPromotionManager::promotion_trace_event(oop new_obj, oop old_obj, 73 size_t obj_size, 74 uint age, bool tenured, 75 const PSPromotionLAB* lab) { 76 // Skip if memory allocation failed 77 if (new_obj != NULL) { 78 const ParallelScavengeTracer* gc_tracer = PSScavenge::gc_tracer(); 79 80 if (lab != NULL) { 81 // Promotion of object through newly allocated PLAB 82 if (gc_tracer->should_report_promotion_in_new_plab_event()) { 83 size_t obj_bytes = obj_size * HeapWordSize; 84 size_t lab_size = lab->capacity(); 85 gc_tracer->report_promotion_in_new_plab_event(old_obj->klass(), obj_bytes, 86 age, tenured, lab_size); 87 } 88 } else { 89 // Promotion of object directly to heap 90 if (gc_tracer->should_report_promotion_outside_plab_event()) { 91 size_t obj_bytes = obj_size * HeapWordSize; 92 gc_tracer->report_promotion_outside_plab_event(old_obj->klass(), obj_bytes, 93 age, tenured); 94 } 95 } 96 } 97 } 98 99 inline void PSPromotionManager::push_contents(oop obj) { 100 obj->ps_push_contents(this); 101 } 102 // 103 // This method is pretty bulky. It would be nice to split it up 104 // into smaller submethods, but we need to be careful not to hurt 105 // performance. 106 // 107 template<bool promote_immediately> 108 inline oop PSPromotionManager::copy_to_survivor_space(oop o) { 109 assert(should_scavenge(&o), "Sanity"); 110 111 oop new_obj = NULL; 112 113 // NOTE! We must be very careful with any methods that access the mark 114 // in o. There may be multiple threads racing on it, and it may be forwarded 115 // at any time. Do not use oop methods for accessing the mark! 116 markOop test_mark = o->mark(); 117 118 // The same test as "o->is_forwarded()" 119 if (!test_mark->is_marked()) { 120 bool new_obj_is_tenured = false; 121 size_t new_obj_size = o->size(); 122 123 // Find the objects age, MT safe. 124 uint age = (test_mark->has_displaced_mark_helper() /* o->has_displaced_mark() */) ? 125 test_mark->displaced_mark_helper()->age() : test_mark->age(); 126 127 if (!promote_immediately) { 128 // Try allocating obj in to-space (unless too old) 129 if (age < PSScavenge::tenuring_threshold()) { 130 new_obj = (oop) _young_lab.allocate(new_obj_size); 131 if (new_obj == NULL && !_young_gen_is_full) { 132 // Do we allocate directly, or flush and refill? 133 if (new_obj_size > (YoungPLABSize / 2)) { 134 // Allocate this object directly 135 new_obj = (oop)young_space()->cas_allocate(new_obj_size); 136 promotion_trace_event(new_obj, o, new_obj_size, age, false, NULL); 137 } else { 138 // Flush and fill 139 _young_lab.flush(); 140 141 HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize); 142 if (lab_base != NULL) { 143 _young_lab.initialize(MemRegion(lab_base, YoungPLABSize)); 144 // Try the young lab allocation again. 145 new_obj = (oop) _young_lab.allocate(new_obj_size); 146 promotion_trace_event(new_obj, o, new_obj_size, age, false, &_young_lab); 147 } else { 148 _young_gen_is_full = true; 149 } 150 } 151 } 152 } 153 } 154 155 // Otherwise try allocating obj tenured 156 if (new_obj == NULL) { 157 #ifndef PRODUCT 158 if (ParallelScavengeHeap::heap()->promotion_should_fail()) { 159 return oop_promotion_failed(o, test_mark); 160 } 161 #endif // #ifndef PRODUCT 162 163 new_obj = (oop) _old_lab.allocate(new_obj_size); 164 new_obj_is_tenured = true; 165 166 if (new_obj == NULL) { 167 if (!_old_gen_is_full) { 168 // Do we allocate directly, or flush and refill? 169 if (new_obj_size > (OldPLABSize / 2)) { 170 // Allocate this object directly 171 new_obj = (oop)old_gen()->cas_allocate(new_obj_size); 172 promotion_trace_event(new_obj, o, new_obj_size, age, true, NULL); 173 } else { 174 // Flush and fill 175 _old_lab.flush(); 176 177 HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize); 178 if(lab_base != NULL) { 179 #ifdef ASSERT 180 // Delay the initialization of the promotion lab (plab). 181 // This exposes uninitialized plabs to card table processing. 182 if (GCWorkerDelayMillis > 0) { 183 os::sleep(Thread::current(), GCWorkerDelayMillis, false); 184 } 185 #endif 186 _old_lab.initialize(MemRegion(lab_base, OldPLABSize)); 187 // Try the old lab allocation again. 188 new_obj = (oop) _old_lab.allocate(new_obj_size); 189 promotion_trace_event(new_obj, o, new_obj_size, age, true, &_old_lab); 190 } 191 } 192 } 193 194 // This is the promotion failed test, and code handling. 195 // The code belongs here for two reasons. It is slightly 196 // different than the code below, and cannot share the 197 // CAS testing code. Keeping the code here also minimizes 198 // the impact on the common case fast path code. 199 200 if (new_obj == NULL) { 201 _old_gen_is_full = true; 202 return oop_promotion_failed(o, test_mark); 203 } 204 } 205 } 206 207 assert(new_obj != NULL, "allocation should have succeeded"); 208 209 // Copy obj 210 Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size); 211 212 // Now we have to CAS in the header. 213 if (o->cas_forward_to(new_obj, test_mark)) { 214 // We won any races, we "own" this object. 215 assert(new_obj == o->forwardee(), "Sanity"); 216 217 // Increment age if obj still in new generation. Now that 218 // we're dealing with a markOop that cannot change, it is 219 // okay to use the non mt safe oop methods. 220 if (!new_obj_is_tenured) { 221 new_obj->incr_age(); 222 assert(young_space()->contains(new_obj), "Attempt to push non-promoted obj"); 223 } 224 225 // Do the size comparison first with new_obj_size, which we 226 // already have. Hopefully, only a few objects are larger than 227 // _min_array_size_for_chunking, and most of them will be arrays. 228 // So, the is->objArray() test would be very infrequent. 229 if (new_obj_size > _min_array_size_for_chunking && 230 new_obj->is_objArray() && 231 PSChunkLargeArrays) { 232 // we'll chunk it 233 oop* const masked_o = mask_chunked_array_oop(o); 234 push_depth(masked_o); 235 TASKQUEUE_STATS_ONLY(++_arrays_chunked; ++_masked_pushes); 236 } else { 237 // we'll just push its contents 238 push_contents(new_obj); 239 } 240 } else { 241 // We lost, someone else "owns" this object 242 guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed."); 243 244 // Try to deallocate the space. If it was directly allocated we cannot 245 // deallocate it, so we have to test. If the deallocation fails, 246 // overwrite with a filler object. 247 if (new_obj_is_tenured) { 248 if (!_old_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) { 249 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size); 250 } 251 } else if (!_young_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) { 252 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size); 253 } 254 255 // don't update this before the unallocation! 256 new_obj = o->forwardee(); 257 } 258 } else { 259 assert(o->is_forwarded(), "Sanity"); 260 new_obj = o->forwardee(); 261 } 262 263 #ifndef PRODUCT 264 // This code must come after the CAS test, or it will print incorrect 265 // information. 266 if (TraceScavenge) { 267 gclog_or_tty->print_cr("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}", 268 should_scavenge(&new_obj) ? "copying" : "tenuring", 269 new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size()); 270 } 271 #endif 272 273 return new_obj; 274 } 275 276 // Attempt to "claim" oop at p via CAS, push the new obj if successful 277 // This version tests the oop* to make sure it is within the heap before 278 // attempting marking. 279 template <class T, bool promote_immediately> 280 inline void PSPromotionManager::copy_and_push_safe_barrier(T* p) { 281 assert(should_scavenge(p, true), "revisiting object?"); 282 283 oop o = oopDesc::load_decode_heap_oop_not_null(p); 284 oop new_obj = o->is_forwarded() 285 ? o->forwardee() 286 : copy_to_survivor_space<promote_immediately>(o); 287 288 #ifndef PRODUCT 289 // This code must come after the CAS test, or it will print incorrect 290 // information. 291 if (TraceScavenge && o->is_forwarded()) { 292 gclog_or_tty->print_cr("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}", 293 "forwarding", 294 new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size()); 295 } 296 #endif 297 298 oopDesc::encode_store_heap_oop_not_null(p, new_obj); 299 300 // We cannot mark without test, as some code passes us pointers 301 // that are outside the heap. These pointers are either from roots 302 // or from metadata. 303 if ((!PSScavenge::is_obj_in_young((HeapWord*)p)) && 304 ParallelScavengeHeap::heap()->is_in_reserved(p)) { 305 if (PSScavenge::is_obj_in_young(new_obj)) { 306 PSScavenge::card_table()->inline_write_ref_field_gc(p, new_obj); 307 } 308 } 309 } 310 311 inline void PSPromotionManager::process_popped_location_depth(StarTask p) { 312 if (is_oop_masked(p)) { 313 assert(PSChunkLargeArrays, "invariant"); 314 oop const old = unmask_chunked_array_oop(p); 315 process_array_chunk(old); 316 } else { 317 if (p.is_narrow()) { 318 assert(UseCompressedOops, "Error"); 319 copy_and_push_safe_barrier<narrowOop, /*promote_immediately=*/false>(p); 320 } else { 321 copy_and_push_safe_barrier<oop, /*promote_immediately=*/false>(p); 322 } 323 } 324 } 325 326 inline bool PSPromotionManager::steal_depth(int queue_num, int* seed, StarTask& t) { 327 return stack_array_depth()->steal(queue_num, seed, t); 328 } 329 330 #if TASKQUEUE_STATS 331 void PSPromotionManager::record_steal(StarTask& p) { 332 if (is_oop_masked(p)) { 333 ++_masked_steals; 334 } 335 } 336 #endif // TASKQUEUE_STATS 337 338 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONMANAGER_INLINE_HPP