1 /* 2 * Copyright (c) 2005, 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 #include "precompiled.hpp" 26 #include "classfile/systemDictionary.hpp" 27 #include "gc/parallel/gcTaskManager.hpp" 28 #include "gc/parallel/objectStartArray.hpp" 29 #include "gc/parallel/parMarkBitMap.hpp" 30 #include "gc/parallel/parallelScavengeHeap.hpp" 31 #include "gc/parallel/psCompactionManager.inline.hpp" 32 #include "gc/parallel/psOldGen.hpp" 33 #include "gc/parallel/psParallelCompact.inline.hpp" 34 #include "gc/shared/taskqueue.inline.hpp" 35 #include "logging/log.hpp" 36 #include "memory/iterator.inline.hpp" 37 #include "oops/instanceKlass.inline.hpp" 38 #include "oops/instanceMirrorKlass.inline.hpp" 39 #include "oops/objArrayKlass.inline.hpp" 40 #include "oops/oop.inline.hpp" 41 #include "runtime/atomic.inline.hpp" 42 43 PSOldGen* ParCompactionManager::_old_gen = NULL; 44 ParCompactionManager** ParCompactionManager::_manager_array = NULL; 45 46 RegionTaskQueue** ParCompactionManager::_region_list = NULL; 47 48 OopTaskQueueSet* ParCompactionManager::_stack_array = NULL; 49 ParCompactionManager::ObjArrayTaskQueueSet* 50 ParCompactionManager::_objarray_queues = NULL; 51 ObjectStartArray* ParCompactionManager::_start_array = NULL; 52 ParMarkBitMap* ParCompactionManager::_mark_bitmap = NULL; 53 RegionTaskQueueSet* ParCompactionManager::_region_array = NULL; 54 55 uint* ParCompactionManager::_recycled_stack_index = NULL; 56 int ParCompactionManager::_recycled_top = -1; 57 int ParCompactionManager::_recycled_bottom = -1; 58 59 ParCompactionManager::ParCompactionManager() : 60 _action(CopyAndUpdate), 61 _region_stack(NULL), 62 _region_stack_index((uint)max_uintx) { 63 64 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); 65 66 _old_gen = heap->old_gen(); 67 _start_array = old_gen()->start_array(); 68 69 marking_stack()->initialize(); 70 _objarray_stack.initialize(); 71 } 72 73 ParCompactionManager::~ParCompactionManager() { 74 delete _recycled_stack_index; 75 } 76 77 void ParCompactionManager::initialize(ParMarkBitMap* mbm) { 78 assert(PSParallelCompact::gc_task_manager() != NULL, 79 "Needed for initialization"); 80 81 _mark_bitmap = mbm; 82 83 uint parallel_gc_threads = PSParallelCompact::gc_task_manager()->workers(); 84 85 assert(_manager_array == NULL, "Attempt to initialize twice"); 86 _manager_array = NEW_C_HEAP_ARRAY(ParCompactionManager*, parallel_gc_threads+1, mtGC); 87 guarantee(_manager_array != NULL, "Could not allocate manager_array"); 88 89 _region_list = NEW_C_HEAP_ARRAY(RegionTaskQueue*, 90 parallel_gc_threads+1, mtGC); 91 guarantee(_region_list != NULL, "Could not initialize promotion manager"); 92 93 _recycled_stack_index = NEW_C_HEAP_ARRAY(uint, parallel_gc_threads, mtGC); 94 95 // parallel_gc-threads + 1 to be consistent with the number of 96 // compaction managers. 97 for(uint i=0; i<parallel_gc_threads + 1; i++) { 98 _region_list[i] = new RegionTaskQueue(); 99 region_list(i)->initialize(); 100 } 101 102 _stack_array = new OopTaskQueueSet(parallel_gc_threads); 103 guarantee(_stack_array != NULL, "Could not allocate stack_array"); 104 _objarray_queues = new ObjArrayTaskQueueSet(parallel_gc_threads); 105 guarantee(_objarray_queues != NULL, "Could not allocate objarray_queues"); 106 _region_array = new RegionTaskQueueSet(parallel_gc_threads); 107 guarantee(_region_array != NULL, "Could not allocate region_array"); 108 109 // Create and register the ParCompactionManager(s) for the worker threads. 110 for(uint i=0; i<parallel_gc_threads; i++) { 111 _manager_array[i] = new ParCompactionManager(); 112 guarantee(_manager_array[i] != NULL, "Could not create ParCompactionManager"); 113 stack_array()->register_queue(i, _manager_array[i]->marking_stack()); 114 _objarray_queues->register_queue(i, &_manager_array[i]->_objarray_stack); 115 region_array()->register_queue(i, region_list(i)); 116 } 117 118 // The VMThread gets its own ParCompactionManager, which is not available 119 // for work stealing. 120 _manager_array[parallel_gc_threads] = new ParCompactionManager(); 121 guarantee(_manager_array[parallel_gc_threads] != NULL, 122 "Could not create ParCompactionManager"); 123 assert(PSParallelCompact::gc_task_manager()->workers() != 0, 124 "Not initialized?"); 125 } 126 127 int ParCompactionManager::pop_recycled_stack_index() { 128 assert(_recycled_bottom <= _recycled_top, "list is empty"); 129 // Get the next available index 130 if (_recycled_bottom < _recycled_top) { 131 uint cur, next, last; 132 do { 133 cur = _recycled_bottom; 134 next = cur + 1; 135 last = Atomic::cmpxchg(next, &_recycled_bottom, cur); 136 } while (cur != last); 137 return _recycled_stack_index[next]; 138 } else { 139 return -1; 140 } 141 } 142 143 void ParCompactionManager::push_recycled_stack_index(uint v) { 144 // Get the next available index 145 int cur = Atomic::add(1, &_recycled_top); 146 _recycled_stack_index[cur] = v; 147 assert(_recycled_bottom <= _recycled_top, "list top and bottom are wrong"); 148 } 149 150 bool ParCompactionManager::should_update() { 151 assert(action() != NotValid, "Action is not set"); 152 return (action() == ParCompactionManager::Update) || 153 (action() == ParCompactionManager::CopyAndUpdate) || 154 (action() == ParCompactionManager::UpdateAndCopy); 155 } 156 157 bool ParCompactionManager::should_copy() { 158 assert(action() != NotValid, "Action is not set"); 159 return (action() == ParCompactionManager::Copy) || 160 (action() == ParCompactionManager::CopyAndUpdate) || 161 (action() == ParCompactionManager::UpdateAndCopy); 162 } 163 164 void ParCompactionManager::region_list_push(uint list_index, 165 size_t region_index) { 166 region_list(list_index)->push(region_index); 167 } 168 169 void ParCompactionManager::verify_region_list_empty(uint list_index) { 170 assert(region_list(list_index)->is_empty(), "Not empty"); 171 } 172 173 ParCompactionManager* 174 ParCompactionManager::gc_thread_compaction_manager(uint index) { 175 assert(index < ParallelGCThreads, "index out of range"); 176 assert(_manager_array != NULL, "Sanity"); 177 return _manager_array[index]; 178 } 179 180 void InstanceKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) { 181 assert(obj != NULL, "can't follow the content of NULL object"); 182 183 cm->follow_klass(this); 184 // Only mark the header and let the scan of the meta-data mark 185 // everything else. 186 187 ParCompactionManager::MarkAndPushClosure cl(cm); 188 InstanceKlass::oop_oop_iterate_oop_maps<true>(obj, &cl); 189 } 190 191 void InstanceMirrorKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) { 192 InstanceKlass::oop_pc_follow_contents(obj, cm); 193 194 // Follow the klass field in the mirror. 195 Klass* klass = java_lang_Class::as_Klass(obj); 196 if (klass != NULL) { 197 // An anonymous class doesn't have its own class loader, so the call 198 // to follow_klass will mark and push its java mirror instead of the 199 // class loader. When handling the java mirror for an anonymous class 200 // we need to make sure its class loader data is claimed, this is done 201 // by calling follow_class_loader explicitly. For non-anonymous classes 202 // the call to follow_class_loader is made when the class loader itself 203 // is handled. 204 if (klass->is_instance_klass() && InstanceKlass::cast(klass)->is_anonymous()) { 205 cm->follow_class_loader(klass->class_loader_data()); 206 } else { 207 cm->follow_klass(klass); 208 } 209 } else { 210 // If klass is NULL then this a mirror for a primitive type. 211 // We don't have to follow them, since they are handled as strong 212 // roots in Universe::oops_do. 213 assert(java_lang_Class::is_primitive(obj), "Sanity check"); 214 } 215 216 ParCompactionManager::MarkAndPushClosure cl(cm); 217 oop_oop_iterate_statics<true>(obj, &cl); 218 } 219 220 void InstanceClassLoaderKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) { 221 InstanceKlass::oop_pc_follow_contents(obj, cm); 222 223 ClassLoaderData * const loader_data = java_lang_ClassLoader::loader_data(obj); 224 if (loader_data != NULL) { 225 cm->follow_class_loader(loader_data); 226 } 227 } 228 229 template <class T> 230 static void oop_pc_follow_contents_specialized(InstanceRefKlass* klass, oop obj, ParCompactionManager* cm) { 231 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj); 232 T heap_oop = oopDesc::load_heap_oop(referent_addr); 233 log_develop(gc, ref)("InstanceRefKlass::oop_pc_follow_contents " PTR_FORMAT, p2i(obj)); 234 if (!oopDesc::is_null(heap_oop)) { 235 oop referent = oopDesc::decode_heap_oop_not_null(heap_oop); 236 if (PSParallelCompact::mark_bitmap()->is_unmarked(referent) && 237 PSParallelCompact::ref_processor()->discover_reference(obj, klass->reference_type())) { 238 // reference already enqueued, referent will be traversed later 239 klass->InstanceKlass::oop_pc_follow_contents(obj, cm); 240 log_develop(gc, ref)(" Non NULL enqueued " PTR_FORMAT, p2i(obj)); 241 return; 242 } else { 243 // treat referent as normal oop 244 log_develop(gc, ref)(" Non NULL normal " PTR_FORMAT, p2i(obj)); 245 cm->mark_and_push(referent_addr); 246 } 247 } 248 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj); 249 // Treat discovered as normal oop, if ref is not "active", 250 // i.e. if next is non-NULL. 251 T next_oop = oopDesc::load_heap_oop(next_addr); 252 if (!oopDesc::is_null(next_oop)) { // i.e. ref is not "active" 253 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj); 254 log_develop(gc, ref)(" Process discovered as normal " PTR_FORMAT, p2i(discovered_addr)); 255 cm->mark_and_push(discovered_addr); 256 } 257 cm->mark_and_push(next_addr); 258 klass->InstanceKlass::oop_pc_follow_contents(obj, cm); 259 } 260 261 262 void InstanceRefKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) { 263 if (UseCompressedOops) { 264 oop_pc_follow_contents_specialized<narrowOop>(this, obj, cm); 265 } else { 266 oop_pc_follow_contents_specialized<oop>(this, obj, cm); 267 } 268 } 269 270 void ObjArrayKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) { 271 cm->follow_klass(this); 272 273 if (UseCompressedOops) { 274 oop_pc_follow_contents_specialized<narrowOop>(objArrayOop(obj), 0, cm); 275 } else { 276 oop_pc_follow_contents_specialized<oop>(objArrayOop(obj), 0, cm); 277 } 278 } 279 280 void TypeArrayKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) { 281 assert(obj->is_typeArray(),"must be a type array"); 282 // Performance tweak: We skip iterating over the klass pointer since we 283 // know that Universe::TypeArrayKlass never moves. 284 } 285 286 void ParCompactionManager::follow_marking_stacks() { 287 do { 288 // Drain the overflow stack first, to allow stealing from the marking stack. 289 oop obj; 290 while (marking_stack()->pop_overflow(obj)) { 291 follow_contents(obj); 292 } 293 while (marking_stack()->pop_local(obj)) { 294 follow_contents(obj); 295 } 296 297 // Process ObjArrays one at a time to avoid marking stack bloat. 298 ObjArrayTask task; 299 if (_objarray_stack.pop_overflow(task) || _objarray_stack.pop_local(task)) { 300 follow_contents((objArrayOop)task.obj(), task.index()); 301 } 302 } while (!marking_stacks_empty()); 303 304 assert(marking_stacks_empty(), "Sanity"); 305 } 306 307 void ParCompactionManager::drain_region_stacks() { 308 do { 309 // Drain overflow stack first so other threads can steal. 310 size_t region_index; 311 while (region_stack()->pop_overflow(region_index)) { 312 PSParallelCompact::fill_and_update_region(this, region_index); 313 } 314 315 while (region_stack()->pop_local(region_index)) { 316 PSParallelCompact::fill_and_update_region(this, region_index); 317 } 318 } while (!region_stack()->is_empty()); 319 }