1 /* 2 * Copyright (c) 2005, 2018, 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.inline.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/access.inline.hpp" 38 #include "oops/compressedOops.inline.hpp" 39 #include "oops/instanceKlass.inline.hpp" 40 #include "oops/instanceMirrorKlass.inline.hpp" 41 #include "oops/objArrayKlass.inline.hpp" 42 #include "oops/oop.inline.hpp" 43 #include "runtime/atomic.hpp" 44 45 PSOldGen* ParCompactionManager::_old_gen = NULL; 46 ParCompactionManager** ParCompactionManager::_manager_array = 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 ParCompactionManager::ParCompactionManager() : 56 _action(CopyAndUpdate) { 57 58 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); 59 60 _old_gen = heap->old_gen(); 61 _start_array = old_gen()->start_array(); 62 63 marking_stack()->initialize(); 64 _objarray_stack.initialize(); 65 _region_stack.initialize(); 66 67 reset_bitmap_query_cache(); 68 } 69 70 void ParCompactionManager::initialize(ParMarkBitMap* mbm) { 71 assert(PSParallelCompact::gc_task_manager() != NULL, 72 "Needed for initialization"); 73 74 _mark_bitmap = mbm; 75 76 uint parallel_gc_threads = PSParallelCompact::gc_task_manager()->workers(); 77 78 assert(_manager_array == NULL, "Attempt to initialize twice"); 79 _manager_array = NEW_C_HEAP_ARRAY(ParCompactionManager*, parallel_gc_threads+1, mtGC); 80 guarantee(_manager_array != NULL, "Could not allocate manager_array"); 81 82 _stack_array = new OopTaskQueueSet(parallel_gc_threads); 83 guarantee(_stack_array != NULL, "Could not allocate stack_array"); 84 _objarray_queues = new ObjArrayTaskQueueSet(parallel_gc_threads); 85 guarantee(_objarray_queues != NULL, "Could not allocate objarray_queues"); 86 _region_array = new RegionTaskQueueSet(parallel_gc_threads); 87 guarantee(_region_array != NULL, "Could not allocate region_array"); 88 89 // Create and register the ParCompactionManager(s) for the worker threads. 90 for(uint i=0; i<parallel_gc_threads; i++) { 91 _manager_array[i] = new ParCompactionManager(); 92 guarantee(_manager_array[i] != NULL, "Could not create ParCompactionManager"); 93 stack_array()->register_queue(i, _manager_array[i]->marking_stack()); 94 _objarray_queues->register_queue(i, &_manager_array[i]->_objarray_stack); 95 region_array()->register_queue(i, _manager_array[i]->region_stack()); 96 } 97 98 // The VMThread gets its own ParCompactionManager, which is not available 99 // for work stealing. 100 _manager_array[parallel_gc_threads] = new ParCompactionManager(); 101 guarantee(_manager_array[parallel_gc_threads] != NULL, 102 "Could not create ParCompactionManager"); 103 assert(PSParallelCompact::gc_task_manager()->workers() != 0, 104 "Not initialized?"); 105 } 106 107 void ParCompactionManager::reset_all_bitmap_query_caches() { 108 uint parallel_gc_threads = PSParallelCompact::gc_task_manager()->workers(); 109 for (uint i=0; i<=parallel_gc_threads; i++) { 110 _manager_array[i]->reset_bitmap_query_cache(); 111 } 112 } 113 114 bool ParCompactionManager::should_update() { 115 assert(action() != NotValid, "Action is not set"); 116 return (action() == ParCompactionManager::Update) || 117 (action() == ParCompactionManager::CopyAndUpdate) || 118 (action() == ParCompactionManager::UpdateAndCopy); 119 } 120 121 bool ParCompactionManager::should_copy() { 122 assert(action() != NotValid, "Action is not set"); 123 return (action() == ParCompactionManager::Copy) || 124 (action() == ParCompactionManager::CopyAndUpdate) || 125 (action() == ParCompactionManager::UpdateAndCopy); 126 } 127 128 ParCompactionManager* 129 ParCompactionManager::gc_thread_compaction_manager(uint index) { 130 assert(index < ParallelGCThreads, "index out of range"); 131 assert(_manager_array != NULL, "Sanity"); 132 return _manager_array[index]; 133 } 134 135 void InstanceKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) { 136 assert(obj != NULL, "can't follow the content of NULL object"); 137 138 cm->follow_klass(this); 139 // Only mark the header and let the scan of the meta-data mark 140 // everything else. 141 142 ParCompactionManager::MarkAndPushClosure cl(cm); 143 InstanceKlass::oop_oop_iterate_oop_maps<true>(obj, &cl); 144 } 145 146 void InstanceMirrorKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) { 147 InstanceKlass::oop_pc_follow_contents(obj, cm); 148 149 // Follow the klass field in the mirror. 150 Klass* klass = java_lang_Class::as_Klass(obj); 151 if (klass != NULL) { 152 // An anonymous class doesn't have its own class loader, so the call 153 // to follow_klass will mark and push its java mirror instead of the 154 // class loader. When handling the java mirror for an anonymous class 155 // we need to make sure its class loader data is claimed, this is done 156 // by calling follow_class_loader explicitly. For non-anonymous classes 157 // the call to follow_class_loader is made when the class loader itself 158 // is handled. 159 if (klass->is_instance_klass() && InstanceKlass::cast(klass)->is_anonymous()) { 160 cm->follow_class_loader(klass->class_loader_data()); 161 } else { 162 cm->follow_klass(klass); 163 } 164 } else { 165 // If klass is NULL then this a mirror for a primitive type. 166 // We don't have to follow them, since they are handled as strong 167 // roots in Universe::oops_do. 168 assert(java_lang_Class::is_primitive(obj), "Sanity check"); 169 } 170 171 ParCompactionManager::MarkAndPushClosure cl(cm); 172 oop_oop_iterate_statics<true>(obj, &cl); 173 } 174 175 void InstanceClassLoaderKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) { 176 InstanceKlass::oop_pc_follow_contents(obj, cm); 177 178 ClassLoaderData * const loader_data = java_lang_ClassLoader::loader_data(obj); 179 if (loader_data != NULL) { 180 cm->follow_class_loader(loader_data); 181 } 182 } 183 184 template <class T> 185 static void oop_pc_follow_contents_specialized(InstanceRefKlass* klass, oop obj, ParCompactionManager* cm) { 186 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr_raw(obj); 187 T heap_oop = RawAccess<>::oop_load(referent_addr); 188 log_develop_trace(gc, ref)("InstanceRefKlass::oop_pc_follow_contents " PTR_FORMAT, p2i(obj)); 189 if (!CompressedOops::is_null(heap_oop)) { 190 oop referent = CompressedOops::decode_not_null(heap_oop); 191 if (PSParallelCompact::mark_bitmap()->is_unmarked(referent) && 192 PSParallelCompact::ref_processor()->discover_reference(obj, klass->reference_type())) { 193 // reference already enqueued, referent will be traversed later 194 klass->InstanceKlass::oop_pc_follow_contents(obj, cm); 195 log_develop_trace(gc, ref)(" Non NULL enqueued " PTR_FORMAT, p2i(obj)); 196 return; 197 } else { 198 // treat referent as normal oop 199 log_develop_trace(gc, ref)(" Non NULL normal " PTR_FORMAT, p2i(obj)); 200 cm->mark_and_push(referent_addr); 201 } 202 } 203 T* next_addr = (T*)java_lang_ref_Reference::next_addr_raw(obj); 204 // Treat discovered as normal oop, if ref is not "active", 205 // i.e. if next is non-NULL. 206 T next_oop = RawAccess<>::oop_load(next_addr); 207 if (!CompressedOops::is_null(next_oop)) { // i.e. ref is not "active" 208 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr_raw(obj); 209 log_develop_trace(gc, ref)(" Process discovered as normal " PTR_FORMAT, p2i(discovered_addr)); 210 cm->mark_and_push(discovered_addr); 211 } 212 cm->mark_and_push(next_addr); 213 klass->InstanceKlass::oop_pc_follow_contents(obj, cm); 214 } 215 216 217 void InstanceRefKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) { 218 if (UseCompressedOops) { 219 oop_pc_follow_contents_specialized<narrowOop>(this, obj, cm); 220 } else { 221 oop_pc_follow_contents_specialized<oop>(this, obj, cm); 222 } 223 } 224 225 void ObjArrayKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) { 226 cm->follow_klass(this); 227 228 if (UseCompressedOops) { 229 oop_pc_follow_contents_specialized<narrowOop>(objArrayOop(obj), 0, cm); 230 } else { 231 oop_pc_follow_contents_specialized<oop>(objArrayOop(obj), 0, cm); 232 } 233 } 234 235 void TypeArrayKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) { 236 assert(obj->is_typeArray(),"must be a type array"); 237 // Performance tweak: We skip iterating over the klass pointer since we 238 // know that Universe::TypeArrayKlass never moves. 239 } 240 241 void ParCompactionManager::follow_marking_stacks() { 242 do { 243 // Drain the overflow stack first, to allow stealing from the marking stack. 244 oop obj; 245 while (marking_stack()->pop_overflow(obj)) { 246 follow_contents(obj); 247 } 248 while (marking_stack()->pop_local(obj)) { 249 follow_contents(obj); 250 } 251 252 // Process ObjArrays one at a time to avoid marking stack bloat. 253 ObjArrayTask task; 254 if (_objarray_stack.pop_overflow(task) || _objarray_stack.pop_local(task)) { 255 follow_contents((objArrayOop)task.obj(), task.index()); 256 } 257 } while (!marking_stacks_empty()); 258 259 assert(marking_stacks_empty(), "Sanity"); 260 } 261 262 void ParCompactionManager::drain_region_stacks() { 263 do { 264 // Drain overflow stack first so other threads can steal. 265 size_t region_index; 266 while (region_stack()->pop_overflow(region_index)) { 267 PSParallelCompact::fill_and_update_region(this, region_index); 268 } 269 270 while (region_stack()->pop_local(region_index)) { 271 PSParallelCompact::fill_and_update_region(this, region_index); 272 } 273 } while (!region_stack()->is_empty()); 274 }