/*

 * Copyright (c) 2002, 2015, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "precompiled.hpp"

#include "classfile/systemDictionary.hpp"

#include "code/codeCache.hpp"

#include "memory/iterator.hpp"

#include "memory/universe.hpp"

#include "oops/oop.inline.hpp"

#include "runtime/fprofiler.hpp"

#include "runtime/thread.hpp"

#include "runtime/vmThread.hpp"

#include "services/management.hpp"

//

// ScavengeRootsTask

//

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

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

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

  PSScavengeRootsClosure roots_closure(pm);

  PSPromoteRootsClosure  roots_to_old_closure(pm);

  switch (_root_type) {

    case universe:

      Universe::oops_do(&roots_closure);

      break;

    case jni_handles:

      JNIHandles::oops_do(&roots_closure);

      break;

    case threads:

    {

      ResourceMark rm;

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

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

    }

    break;

    case object_synchronizer:

      ObjectSynchronizer::oops_do(&roots_closure);

      break;

    case flat_profiler:

      FlatProfiler::oops_do(&roots_closure);

      break;

    case system_dictionary:

      SystemDictionary::oops_do(&roots_closure);

      break;

    case class_loader_data:

    {

      PSScavengeKlassClosure klass_closure(pm);

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

    }

    break;

    case management:

      Management::oops_do(&roots_closure);

      break;

    case jvmti:

      JvmtiExport::oops_do(&roots_closure);

      break;

    case code_cache:

      {

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

        CodeCache::scavenge_root_nmethods_do(&each_scavengable_code_blob);

      }

      break;

    default:

      fatal("Unknown root type");

  }

  // Do the real work

  pm->drain_stacks(false);

}

//

// ThreadRootsTask

//

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

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

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

  PSScavengeRootsClosure roots_closure(pm);

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

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

  if (_java_thread != NULL)

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

  if (_vm_thread != NULL)

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

  // Do the real work

  pm->drain_stacks(false);

}

//

// StealTask

//

StealTask::StealTask(ParallelTaskTerminator* t) :

  _terminator(t) {}

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

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

  PSPromotionManager* pm =

    PSPromotionManager::gc_thread_promotion_manager(which);

  pm->drain_stacks(true);

  guarantee(pm->stacks_empty(),

            "stacks should be empty at this point");

  int random_seed = 17;

  while(true) {

    StarTask p;

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

      TASKQUEUE_STATS_ONLY(pm->record_steal(p));

      pm->process_popped_location_depth(p);

      pm->drain_stacks_depth(true);

    } else {

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

        break;

      }

    }

  }

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

}

//

// OldToYoungRootsTask

//

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

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

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

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

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

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

  assert(_stripe_number < ParallelGCThreads, "Sanity");

  {

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

    CardTableExtension* card_table =

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

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

                                           _gen->object_space(),

                                           _gen_top,

                                           pm,

                                           _stripe_number,

                                           _stripe_total);

    // Do the real work

    pm->drain_stacks(false);

  }

}