/*

 * Copyright (c) 2005, 2019, 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 "aot/aotLoader.hpp"

#include "classfile/classLoaderDataGraph.hpp"

#include "classfile/systemDictionary.hpp"

#include "code/codeCache.hpp"

#include "gc/parallel/parallelScavengeHeap.hpp"

#include "gc/parallel/pcTasks.hpp"

#include "gc/parallel/psCompactionManager.inline.hpp"

#include "gc/parallel/psParallelCompact.inline.hpp"

#include "gc/shared/collectedHeap.hpp"

#include "gc/shared/gcTimer.hpp"

#include "gc/shared/gcTraceTime.inline.hpp"

#include "logging/log.hpp"

#include "memory/iterator.inline.hpp"

#include "memory/resourceArea.hpp"

#include "memory/universe.hpp"

#include "oops/objArrayKlass.inline.hpp"

#include "oops/oop.inline.hpp"

#include "prims/jvmtiExport.hpp"

#include "runtime/jniHandles.hpp"

#include "runtime/thread.hpp"

#include "runtime/vmThread.hpp"

#include "services/management.hpp"

#include "utilities/stack.inline.hpp"

//

// ThreadRootsMarkingTask

//

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

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

  ResourceMark rm;

  ParCompactionManager* cm =

    ParCompactionManager::gc_thread_compaction_manager(which);

  PCMarkAndPushClosure mark_and_push_closure(cm);

  MarkingCodeBlobClosure mark_and_push_in_blobs(&mark_and_push_closure, !CodeBlobToOopClosure::FixRelocations);

  _thread->oops_do(&mark_and_push_closure, &mark_and_push_in_blobs);

  // Do the real work

  cm->follow_marking_stacks();

}

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

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

  ParCompactionManager* cm =

    ParCompactionManager::gc_thread_compaction_manager(which);

  PCMarkAndPushClosure mark_and_push_closure(cm);

  switch (_root_type) {

    case universe:

      Universe::oops_do(&mark_and_push_closure);

      break;

    case jni_handles:

      JNIHandles::oops_do(&mark_and_push_closure);

      break;

    case threads:

    {

      ResourceMark rm;

      MarkingCodeBlobClosure each_active_code_blob(&mark_and_push_closure, !CodeBlobToOopClosure::FixRelocations);

      Threads::oops_do(&mark_and_push_closure, &each_active_code_blob);

    }

    break;

    case object_synchronizer:

      ObjectSynchronizer::oops_do(&mark_and_push_closure);

      break;

    case management:

      Management::oops_do(&mark_and_push_closure);

      break;

    case jvmti:

      JvmtiExport::oops_do(&mark_and_push_closure);

      break;

    case system_dictionary:

      SystemDictionary::oops_do(&mark_and_push_closure);

      break;

    case class_loader_data: {

        CLDToOopClosure cld_closure(&mark_and_push_closure, ClassLoaderData::_claim_strong);

        ClassLoaderDataGraph::always_strong_cld_do(&cld_closure);

      }

      break;

    case code_cache:

      // Do not treat nmethods as strong roots for mark/sweep, since we can unload them.

      //ScavengableNMethods::scavengable_nmethods_do(CodeBlobToOopClosure(&mark_and_push_closure));

      AOTLoader::oops_do(&mark_and_push_closure);

      break;

    default:

      fatal("Unknown root type");

  }

  // Do the real work

  cm->follow_marking_stacks();

}

//

// RefProcTaskProxy

//

void RefProcTaskProxy::do_it(GCTaskManager* manager, uint which)

{

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

  ParCompactionManager* cm =

    ParCompactionManager::gc_thread_compaction_manager(which);

  PCMarkAndPushClosure mark_and_push_closure(cm);

  ParCompactionManager::FollowStackClosure follow_stack_closure(cm);

  _rp_task.work(_work_id, *PSParallelCompact::is_alive_closure(),

                mark_and_push_closure, follow_stack_closure);

}

//

// RefProcTaskExecutor

//

void RefProcTaskExecutor::execute(ProcessTask& task, uint ergo_workers)

{

  ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();

  uint active_gc_threads = heap->gc_task_manager()->active_workers();

  assert(active_gc_threads == ergo_workers,

         "Ergonomically chosen workers (%u) must be equal to active workers (%u)",

         ergo_workers, active_gc_threads);

  OopTaskQueueSet* qset = ParCompactionManager::stack_array();

  TaskTerminator terminator(active_gc_threads, qset);

  GCTaskQueue* q = GCTaskQueue::create();

  for(uint i=0; i<active_gc_threads; i++) {

    q->enqueue(new RefProcTaskProxy(task, i));

  }

  if (task.marks_oops_alive() && (active_gc_threads>1)) {

    for (uint j=0; j<active_gc_threads; j++) {

      q->enqueue(new StealMarkingTask(terminator.terminator()));

    }

  }

  PSParallelCompact::gc_task_manager()->execute_and_wait(q);

}

//

// StealMarkingTask

//

StealMarkingTask::StealMarkingTask(ParallelTaskTerminator* t) :

  _terminator(t) {}

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

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

  ParCompactionManager* cm =

    ParCompactionManager::gc_thread_compaction_manager(which);

  oop obj = NULL;

  ObjArrayTask task;

  do {

    while (ParCompactionManager::steal_objarray(which,  task)) {

      cm->follow_array((objArrayOop)task.obj(), task.index());

      cm->follow_marking_stacks();

    }

    while (ParCompactionManager::steal(which, obj)) {

      cm->follow_contents(obj);

      cm->follow_marking_stacks();

    }

  } while (!terminator()->offer_termination());

}

//

// CompactionWithStealingTask

//

CompactionWithStealingTask::CompactionWithStealingTask(ParallelTaskTerminator* t):

  _terminator(t) {}

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

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

  ParCompactionManager* cm =

    ParCompactionManager::gc_thread_compaction_manager(which);

  // Drain the stacks that have been preloaded with regions

  // that are ready to fill.

  cm->drain_region_stacks();

  guarantee(cm->region_stack()->is_empty(), "Not empty");

  size_t region_index = 0;

  while(true) {

    if (ParCompactionManager::steal(which, region_index)) {

      PSParallelCompact::fill_and_update_region(cm, region_index);

      cm->drain_region_stacks();

    } else {

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

        break;

      }

      // Go around again.

    }

  }

  return;

}

UpdateDensePrefixTask::UpdateDensePrefixTask(

                                   PSParallelCompact::SpaceId space_id,

                                   size_t region_index_start,

                                   size_t region_index_end) :

  _space_id(space_id), _region_index_start(region_index_start),

  _region_index_end(region_index_end) {}

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

  ParCompactionManager* cm =

    ParCompactionManager::gc_thread_compaction_manager(which);

  PSParallelCompact::update_and_deadwood_in_dense_prefix(cm,

                                                         _space_id,

                                                         _region_index_start,

                                                         _region_index_end);

}