1 /*
   2  * Copyright (c) 2005, 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 #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 "oops/valueArrayKlass.inline.hpp"
  42 #include "runtime/atomic.inline.hpp"
  43 
  44 PSOldGen*            ParCompactionManager::_old_gen = NULL;
  45 ParCompactionManager**  ParCompactionManager::_manager_array = NULL;
  46 
  47 RegionTaskQueue**              ParCompactionManager::_region_list = NULL;
  48 
  49 OopTaskQueueSet*     ParCompactionManager::_stack_array = NULL;
  50 ParCompactionManager::ObjArrayTaskQueueSet*
  51   ParCompactionManager::_objarray_queues = NULL;
  52 ObjectStartArray*    ParCompactionManager::_start_array = NULL;
  53 ParMarkBitMap*       ParCompactionManager::_mark_bitmap = NULL;
  54 RegionTaskQueueSet*  ParCompactionManager::_region_array = NULL;
  55 
  56 uint*                 ParCompactionManager::_recycled_stack_index = NULL;
  57 int                   ParCompactionManager::_recycled_top = -1;
  58 int                   ParCompactionManager::_recycled_bottom = -1;
  59 
  60 ParCompactionManager::ParCompactionManager() :
  61     _action(CopyAndUpdate),
  62     _region_stack(NULL),
  63     _region_stack_index((uint)max_uintx) {
  64 
  65   ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
  66 
  67   _old_gen = heap->old_gen();
  68   _start_array = old_gen()->start_array();
  69 
  70   marking_stack()->initialize();
  71   _objarray_stack.initialize();
  72 
  73   reset_bitmap_query_cache();
  74 }
  75 
  76 ParCompactionManager::~ParCompactionManager() {
  77   delete _recycled_stack_index;
  78 }
  79 
  80 void ParCompactionManager::initialize(ParMarkBitMap* mbm) {
  81   assert(PSParallelCompact::gc_task_manager() != NULL,
  82     "Needed for initialization");
  83 
  84   _mark_bitmap = mbm;
  85 
  86   uint parallel_gc_threads = PSParallelCompact::gc_task_manager()->workers();
  87 
  88   assert(_manager_array == NULL, "Attempt to initialize twice");
  89   _manager_array = NEW_C_HEAP_ARRAY(ParCompactionManager*, parallel_gc_threads+1, mtGC);
  90   guarantee(_manager_array != NULL, "Could not allocate manager_array");
  91 
  92   _region_list = NEW_C_HEAP_ARRAY(RegionTaskQueue*,
  93                          parallel_gc_threads+1, mtGC);
  94   guarantee(_region_list != NULL, "Could not initialize promotion manager");
  95 
  96   _recycled_stack_index = NEW_C_HEAP_ARRAY(uint, parallel_gc_threads, mtGC);
  97 
  98   // parallel_gc-threads + 1 to be consistent with the number of
  99   // compaction managers.
 100   for(uint i=0; i<parallel_gc_threads + 1; i++) {
 101     _region_list[i] = new RegionTaskQueue();
 102     region_list(i)->initialize();
 103   }
 104 
 105   _stack_array = new OopTaskQueueSet(parallel_gc_threads);
 106   guarantee(_stack_array != NULL, "Could not allocate stack_array");
 107   _objarray_queues = new ObjArrayTaskQueueSet(parallel_gc_threads);
 108   guarantee(_objarray_queues != NULL, "Could not allocate objarray_queues");
 109   _region_array = new RegionTaskQueueSet(parallel_gc_threads);
 110   guarantee(_region_array != NULL, "Could not allocate region_array");
 111 
 112   // Create and register the ParCompactionManager(s) for the worker threads.
 113   for(uint i=0; i<parallel_gc_threads; i++) {
 114     _manager_array[i] = new ParCompactionManager();
 115     guarantee(_manager_array[i] != NULL, "Could not create ParCompactionManager");
 116     stack_array()->register_queue(i, _manager_array[i]->marking_stack());
 117     _objarray_queues->register_queue(i, &_manager_array[i]->_objarray_stack);
 118     region_array()->register_queue(i, region_list(i));
 119   }
 120 
 121   // The VMThread gets its own ParCompactionManager, which is not available
 122   // for work stealing.
 123   _manager_array[parallel_gc_threads] = new ParCompactionManager();
 124   guarantee(_manager_array[parallel_gc_threads] != NULL,
 125     "Could not create ParCompactionManager");
 126   assert(PSParallelCompact::gc_task_manager()->workers() != 0,
 127     "Not initialized?");
 128 }
 129 
 130 void ParCompactionManager::reset_all_bitmap_query_caches() {
 131   uint parallel_gc_threads = PSParallelCompact::gc_task_manager()->workers();
 132   for (uint i=0; i<=parallel_gc_threads; i++) {
 133     _manager_array[i]->reset_bitmap_query_cache();
 134   }
 135 }
 136 
 137 int ParCompactionManager::pop_recycled_stack_index() {
 138   assert(_recycled_bottom <= _recycled_top, "list is empty");
 139   // Get the next available index
 140   if (_recycled_bottom < _recycled_top) {
 141     uint cur, next, last;
 142     do {
 143       cur = _recycled_bottom;
 144       next = cur + 1;
 145       last = Atomic::cmpxchg(next, &_recycled_bottom, cur);
 146     } while (cur != last);
 147     return _recycled_stack_index[next];
 148   } else {
 149     return -1;
 150   }
 151 }
 152 
 153 void ParCompactionManager::push_recycled_stack_index(uint v) {
 154   // Get the next available index
 155   int cur = Atomic::add(1, &_recycled_top);
 156   _recycled_stack_index[cur] = v;
 157   assert(_recycled_bottom <= _recycled_top, "list top and bottom are wrong");
 158 }
 159 
 160 bool ParCompactionManager::should_update() {
 161   assert(action() != NotValid, "Action is not set");
 162   return (action() == ParCompactionManager::Update) ||
 163          (action() == ParCompactionManager::CopyAndUpdate) ||
 164          (action() == ParCompactionManager::UpdateAndCopy);
 165 }
 166 
 167 bool ParCompactionManager::should_copy() {
 168   assert(action() != NotValid, "Action is not set");
 169   return (action() == ParCompactionManager::Copy) ||
 170          (action() == ParCompactionManager::CopyAndUpdate) ||
 171          (action() == ParCompactionManager::UpdateAndCopy);
 172 }
 173 
 174 void ParCompactionManager::region_list_push(uint list_index,
 175                                             size_t region_index) {
 176   region_list(list_index)->push(region_index);
 177 }
 178 
 179 void ParCompactionManager::verify_region_list_empty(uint list_index) {
 180   assert(region_list(list_index)->is_empty(), "Not empty");
 181 }
 182 
 183 ParCompactionManager*
 184 ParCompactionManager::gc_thread_compaction_manager(uint index) {
 185   assert(index < ParallelGCThreads, "index out of range");
 186   assert(_manager_array != NULL, "Sanity");
 187   return _manager_array[index];
 188 }
 189 
 190 void InstanceKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
 191   assert(obj != NULL, "can't follow the content of NULL object");
 192 
 193   cm->follow_klass(this);
 194   // Only mark the header and let the scan of the meta-data mark
 195   // everything else.
 196 
 197   ParCompactionManager::MarkAndPushClosure cl(cm);
 198   InstanceKlass::oop_oop_iterate_oop_maps<true>(obj, &cl);
 199 }
 200 
 201 void InstanceMirrorKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
 202   InstanceKlass::oop_pc_follow_contents(obj, cm);
 203 
 204   // Follow the klass field in the mirror.
 205   Klass* klass = java_lang_Class::as_Klass(obj);
 206   if (klass != NULL) {
 207     // An anonymous class doesn't have its own class loader, so the call
 208     // to follow_klass will mark and push its java mirror instead of the
 209     // class loader. When handling the java mirror for an anonymous class
 210     // we need to make sure its class loader data is claimed, this is done
 211     // by calling follow_class_loader explicitly. For non-anonymous classes
 212     // the call to follow_class_loader is made when the class loader itself
 213     // is handled.
 214     if (klass->is_instance_klass() && InstanceKlass::cast(klass)->is_anonymous()) {
 215       cm->follow_class_loader(klass->class_loader_data());
 216     } else {
 217       cm->follow_klass(klass);
 218     }
 219   } else {
 220     // If klass is NULL then this a mirror for a primitive type.
 221     // We don't have to follow them, since they are handled as strong
 222     // roots in Universe::oops_do.
 223     assert(java_lang_Class::is_primitive(obj), "Sanity check");
 224   }
 225 
 226   ParCompactionManager::MarkAndPushClosure cl(cm);
 227   oop_oop_iterate_statics<true>(obj, &cl);
 228 }
 229 
 230 void InstanceClassLoaderKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
 231   InstanceKlass::oop_pc_follow_contents(obj, cm);
 232 
 233   ClassLoaderData * const loader_data = java_lang_ClassLoader::loader_data(obj);
 234   if (loader_data != NULL) {
 235     cm->follow_class_loader(loader_data);
 236   }
 237 }
 238 
 239 template <class T>
 240 static void oop_pc_follow_contents_specialized(InstanceRefKlass* klass, oop obj, ParCompactionManager* cm) {
 241   T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj);
 242   T heap_oop = oopDesc::load_heap_oop(referent_addr);
 243   log_develop_trace(gc, ref)("InstanceRefKlass::oop_pc_follow_contents " PTR_FORMAT, p2i(obj));
 244   if (!oopDesc::is_null(heap_oop)) {
 245     oop referent = oopDesc::decode_heap_oop_not_null(heap_oop);
 246     if (PSParallelCompact::mark_bitmap()->is_unmarked(referent) &&
 247         PSParallelCompact::ref_processor()->discover_reference(obj, klass->reference_type())) {
 248       // reference already enqueued, referent will be traversed later
 249       klass->InstanceKlass::oop_pc_follow_contents(obj, cm);
 250       log_develop_trace(gc, ref)("       Non NULL enqueued " PTR_FORMAT, p2i(obj));
 251       return;
 252     } else {
 253       // treat referent as normal oop
 254       log_develop_trace(gc, ref)("       Non NULL normal " PTR_FORMAT, p2i(obj));
 255       cm->mark_and_push(referent_addr);
 256     }
 257   }
 258   T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj);
 259   // Treat discovered as normal oop, if ref is not "active",
 260   // i.e. if next is non-NULL.
 261   T  next_oop = oopDesc::load_heap_oop(next_addr);
 262   if (!oopDesc::is_null(next_oop)) { // i.e. ref is not "active"
 263     T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj);
 264     log_develop_trace(gc, ref)("   Process discovered as normal " PTR_FORMAT, p2i(discovered_addr));
 265     cm->mark_and_push(discovered_addr);
 266   }
 267   cm->mark_and_push(next_addr);
 268   klass->InstanceKlass::oop_pc_follow_contents(obj, cm);
 269 }
 270 
 271 
 272 void InstanceRefKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
 273   if (UseCompressedOops) {
 274     oop_pc_follow_contents_specialized<narrowOop>(this, obj, cm);
 275   } else {
 276     oop_pc_follow_contents_specialized<oop>(this, obj, cm);
 277   }
 278 }
 279 
 280 void ObjArrayKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
 281   cm->follow_klass(this);
 282 
 283   if (UseCompressedOops) {
 284     oop_pc_follow_contents_specialized<narrowOop>(objArrayOop(obj), 0, cm);
 285   } else {
 286     oop_pc_follow_contents_specialized<oop>(objArrayOop(obj), 0, cm);
 287   }
 288 }
 289 
 290 void TypeArrayKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
 291   assert(obj->is_typeArray(),"must be a type array");
 292   // Performance tweak: We skip iterating over the klass pointer since we
 293   // know that Universe::TypeArrayKlass never moves.
 294 }
 295 
 296 void ValueArrayKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
 297   assert(obj->is_valueArray(),"must be a value array");
 298 
 299   cm->follow_klass(this);
 300   if (contains_oops()) {
 301     Unimplemented(); // Don't have embedded oops to test with just now
 302   }
 303 }
 304 
 305 void ParCompactionManager::follow_marking_stacks() {
 306   do {
 307     // Drain the overflow stack first, to allow stealing from the marking stack.
 308     oop obj;
 309     while (marking_stack()->pop_overflow(obj)) {
 310       follow_contents(obj);
 311     }
 312     while (marking_stack()->pop_local(obj)) {
 313       follow_contents(obj);
 314     }
 315 
 316     // Process ObjArrays one at a time to avoid marking stack bloat.
 317     ObjArrayTask task;
 318     if (_objarray_stack.pop_overflow(task) || _objarray_stack.pop_local(task)) {
 319       follow_contents((objArrayOop)task.obj(), task.index());
 320     }
 321   } while (!marking_stacks_empty());
 322 
 323   assert(marking_stacks_empty(), "Sanity");
 324 }
 325 
 326 void ParCompactionManager::drain_region_stacks() {
 327   do {
 328     // Drain overflow stack first so other threads can steal.
 329     size_t region_index;
 330     while (region_stack()->pop_overflow(region_index)) {
 331       PSParallelCompact::fill_and_update_region(this, region_index);
 332     }
 333 
 334     while (region_stack()->pop_local(region_index)) {
 335       PSParallelCompact::fill_and_update_region(this, region_index);
 336     }
 337   } while (!region_stack()->is_empty());
 338 }