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