1 /*

     2  * Copyright (c) 2002, 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 "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/universe.hpp"

    38 #include "oops/oop.inline.hpp"

    39 #include "runtime/fprofiler.hpp"

    40 #include "runtime/thread.hpp"

    41 #include "runtime/vmThread.hpp"

    42 #include "services/management.hpp"

    43 

    44 //

    45 // ScavengeRootsTask

    46 //

    47 

    48 void ScavengeRootsTask::do_it(GCTaskManager* manager, uint which) {

    49   assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");

    50 

    51   PSPromotionManager* pm = PSPromotionManager::gc_thread_promotion_manager(which);

    52   PSScavengeRootsClosure roots_closure(pm);

    53   PSPromoteRootsClosure  roots_to_old_closure(pm);

    54 

    55   switch (_root_type) {

    56     case universe:

    57       Universe::oops_do(&roots_closure);

    58       break;

    59 

    60     case jni_handles:

    61       JNIHandles::oops_do(&roots_closure);

    62       break;

    63 

    64     case threads:

    65     {

    66       ResourceMark rm;

    67       CLDClosure* cld_closure = NULL; // Not needed. All CLDs are already visited.

    68       Threads::oops_do(&roots_closure, cld_closure, NULL);

    69     }

    70     break;

    71 

    72     case object_synchronizer:

    73       ObjectSynchronizer::oops_do(&roots_closure);

    74       break;

    75 

    76     case flat_profiler:

    77       FlatProfiler::oops_do(&roots_closure);

    78       break;

    79 

    80     case system_dictionary:

    81       SystemDictionary::oops_do(&roots_closure);

    82       break;

    83 

    84     case class_loader_data:

    85     {

    86       PSScavengeKlassClosure klass_closure(pm);

    87       ClassLoaderDataGraph::oops_do(&roots_closure, &klass_closure, false);

    88     }

    89     break;

    90 

    91     case management:

    92       Management::oops_do(&roots_closure);

    93       break;

    94 

    95     case jvmti:

    96       JvmtiExport::oops_do(&roots_closure);

    97       break;

    98 

    99 

   100     case code_cache:

   101       {

   102         MarkingCodeBlobClosure each_scavengable_code_blob(&roots_to_old_closure, CodeBlobToOopClosure::FixRelocations);

   103         CodeCache::scavenge_root_nmethods_do(&each_scavengable_code_blob);

   104       }

   105       break;

   106 

   107     default:

   108       fatal("Unknown root type");

   109   }

   110 

   111   // Do the real work

   112   pm->drain_stacks(false);

   113 }

   114 

   115 //

   116 // ThreadRootsTask

   117 //

   118 

   119 void ThreadRootsTask::do_it(GCTaskManager* manager, uint which) {

   120   assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");

   121 

   122   PSPromotionManager* pm = PSPromotionManager::gc_thread_promotion_manager(which);

   123   PSScavengeRootsClosure roots_closure(pm);

   124   CLDClosure* roots_from_clds = NULL;  // Not needed. All CLDs are already visited.

   125   MarkingCodeBlobClosure roots_in_blobs(&roots_closure, CodeBlobToOopClosure::FixRelocations);

   126 

   127   if (_java_thread != NULL)

   128     _java_thread->oops_do(&roots_closure, roots_from_clds, &roots_in_blobs);

   129 

   130   if (_vm_thread != NULL)

   131     _vm_thread->oops_do(&roots_closure, roots_from_clds, &roots_in_blobs);

   132 

   133   // Do the real work

   134   pm->drain_stacks(false);

   135 }

   136 

   137 //

   138 // StealTask

   139 //

   140 

   141 StealTask::StealTask(ParallelTaskTerminator* t) :

   142   _terminator(t) {}

   143 

   144 void StealTask::do_it(GCTaskManager* manager, uint which) {

   145   assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");

   146 

   147   PSPromotionManager* pm =

   148     PSPromotionManager::gc_thread_promotion_manager(which);

   149   pm->drain_stacks(true);

   150   guarantee(pm->stacks_empty(),

   151             "stacks should be empty at this point");

   152 

   153   int random_seed = 17;

   154   while(true) {

   155     StarTask p;

   156     if (PSPromotionManager::steal_depth(which, &random_seed, p)) {

   157       TASKQUEUE_STATS_ONLY(pm->record_steal(p));

   158       pm->process_popped_location_depth(p);

   159       pm->drain_stacks_depth(true);

   160     } else {

   161       if (terminator()->offer_termination()) {

   162         break;

   163       }

   164     }

   165   }

   166   guarantee(pm->stacks_empty(), "stacks should be empty at this point");

   167 }

   168 

   169 //

   170 // OldToYoungRootsTask

   171 //

   172 

   173 void OldToYoungRootsTask::do_it(GCTaskManager* manager, uint which) {

   174   // There are not old-to-young pointers if the old gen is empty.

   175   assert(!_gen->object_space()->is_empty(),

   176     "Should not be called is there is no work");

   177   assert(_gen != NULL, "Sanity");

   178   assert(_gen->object_space()->contains(_gen_top) || _gen_top == _gen->object_space()->top(), "Sanity");

   179   assert(_stripe_number < ParallelGCThreads, "Sanity");

   180 

   181   {

   182     PSPromotionManager* pm = PSPromotionManager::gc_thread_promotion_manager(which);

   183     CardTableExtension* card_table =

   184       barrier_set_cast<CardTableExtension>(ParallelScavengeHeap::heap()->barrier_set());

   185 

   186     card_table->scavenge_contents_parallel(_gen->start_array(),

   187                                            _gen->object_space(),

   188                                            _gen_top,

   189                                            pm,

   190                                            _stripe_number,

   191                                            _stripe_total);

   192 

   193     // Do the real work

   194     pm->drain_stacks(false);

   195   }

   196 }