1 /*
   2  * Copyright (c) 2002, 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 "code/codeCache.hpp"
  28 #include "gc/parallel/cardTableExtension.hpp"
  29 #include "gc/parallel/gcTaskManager.hpp"
  30 #include "gc/parallel/psMarkSweep.hpp"
  31 #include "gc/parallel/psPromotionManager.hpp"
  32 #include "gc/parallel/psPromotionManager.inline.hpp"
  33 #include "gc/parallel/psScavenge.inline.hpp"
  34 #include "gc/parallel/psTasks.hpp"
  35 #include "gc/shared/taskqueue.inline.hpp"
  36 #include "memory/iterator.hpp"
  37 #include "memory/resourceArea.hpp"
  38 #include "memory/universe.hpp"
  39 #include "oops/oop.inline.hpp"
  40 #include "runtime/fprofiler.hpp"
  41 #include "runtime/thread.hpp"
  42 #include "runtime/vmThread.hpp"
  43 #include "services/management.hpp"
  44 
  45 //
  46 // ScavengeRootsTask
  47 //
  48 
  49 void ScavengeRootsTask::do_it(GCTaskManager* manager, uint which) {
  50   assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");
  51 
  52   PSPromotionManager* pm = PSPromotionManager::gc_thread_promotion_manager(which);
  53   PSScavengeRootsClosure roots_closure(pm);
  54   PSPromoteRootsClosure  roots_to_old_closure(pm);
  55 
  56   switch (_root_type) {
  57     case universe:
  58       Universe::oops_do(&roots_closure);
  59       break;
  60 
  61     case jni_handles:
  62       JNIHandles::oops_do(&roots_closure);
  63       break;
  64 
  65     case threads:
  66     {
  67       ResourceMark rm;
  68       CLDClosure* cld_closure = NULL; // Not needed. All CLDs are already visited.
  69       Threads::oops_do(&roots_closure, cld_closure, NULL);
  70     }
  71     break;
  72 
  73     case object_synchronizer:
  74       ObjectSynchronizer::oops_do(&roots_closure);
  75       break;
  76 
  77     case flat_profiler:
  78       FlatProfiler::oops_do(&roots_closure);
  79       break;
  80 
  81     case system_dictionary:
  82       SystemDictionary::oops_do(&roots_closure);
  83       break;
  84 
  85     case class_loader_data:
  86     {
  87       PSScavengeKlassClosure klass_closure(pm);
  88       ClassLoaderDataGraph::oops_do(&roots_closure, &klass_closure, false);
  89     }
  90     break;
  91 
  92     case management:
  93       Management::oops_do(&roots_closure);
  94       break;
  95 
  96     case jvmti:
  97       JvmtiExport::oops_do(&roots_closure);
  98       break;
  99 
 100 
 101     case code_cache:
 102       {
 103         MarkingCodeBlobClosure each_scavengable_code_blob(&roots_to_old_closure, CodeBlobToOopClosure::FixRelocations);
 104         CodeCache::scavenge_root_nmethods_do(&each_scavengable_code_blob);
 105       }
 106       break;
 107 
 108     default:
 109       fatal("Unknown root type");
 110   }
 111 
 112   // Do the real work
 113   pm->drain_stacks(false);
 114 }
 115 
 116 //
 117 // ThreadRootsTask
 118 //
 119 
 120 void ThreadRootsTask::do_it(GCTaskManager* manager, uint which) {
 121   assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");
 122 
 123   PSPromotionManager* pm = PSPromotionManager::gc_thread_promotion_manager(which);
 124   PSScavengeRootsClosure roots_closure(pm);
 125   CLDClosure* roots_from_clds = NULL;  // Not needed. All CLDs are already visited.
 126   MarkingCodeBlobClosure roots_in_blobs(&roots_closure, CodeBlobToOopClosure::FixRelocations);
 127 
 128   if (_java_thread != NULL)
 129     _java_thread->oops_do(&roots_closure, roots_from_clds, &roots_in_blobs);
 130 
 131   if (_vm_thread != NULL)
 132     _vm_thread->oops_do(&roots_closure, roots_from_clds, &roots_in_blobs);
 133 
 134   // Do the real work
 135   pm->drain_stacks(false);
 136 }
 137 
 138 //
 139 // StealTask
 140 //
 141 
 142 StealTask::StealTask(ParallelTaskTerminator* t) :
 143   _terminator(t) {}
 144 
 145 void StealTask::do_it(GCTaskManager* manager, uint which) {
 146   assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");
 147 
 148   PSPromotionManager* pm =
 149     PSPromotionManager::gc_thread_promotion_manager(which);
 150   pm->drain_stacks(true);
 151   guarantee(pm->stacks_empty(),
 152             "stacks should be empty at this point");
 153 
 154   int random_seed = 17;
 155   while(true) {
 156     StarTask p;
 157     if (PSPromotionManager::steal_depth(which, &random_seed, p)) {
 158       TASKQUEUE_STATS_ONLY(pm->record_steal(p));
 159       pm->process_popped_location_depth(p);
 160       pm->drain_stacks_depth(true);
 161     } else {
 162       if (terminator()->offer_termination()) {
 163         break;
 164       }
 165     }
 166   }
 167   guarantee(pm->stacks_empty(), "stacks should be empty at this point");
 168 }
 169 
 170 //
 171 // OldToYoungRootsTask
 172 //
 173 
 174 void OldToYoungRootsTask::do_it(GCTaskManager* manager, uint which) {
 175   // There are not old-to-young pointers if the old gen is empty.
 176   assert(!_old_gen->object_space()->is_empty(),
 177     "Should not be called is there is no work");
 178   assert(_old_gen != NULL, "Sanity");
 179   assert(_old_gen->object_space()->contains(_gen_top) || _gen_top == _old_gen->object_space()->top(), "Sanity");
 180   assert(_stripe_number < ParallelGCThreads, "Sanity");
 181 
 182   {
 183     PSPromotionManager* pm = PSPromotionManager::gc_thread_promotion_manager(which);
 184     CardTableExtension* card_table =
 185       barrier_set_cast<CardTableExtension>(ParallelScavengeHeap::heap()->barrier_set());
 186 
 187     card_table->scavenge_contents_parallel(_old_gen->start_array(),
 188                                            _old_gen->object_space(),
 189                                            _gen_top,
 190                                            pm,
 191                                            _stripe_number,
 192                                            _stripe_total);
 193 
 194     // Do the real work
 195     pm->drain_stacks(false);
 196   }
 197 }