/*
 * Copyright (c) 2002, 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 "classfile/systemDictionary.hpp"
#include "code/codeCache.hpp"
#include "gc/parallel/gcTaskManager.hpp"
#include "gc/parallel/parallelScavengeHeap.inline.hpp"
#include "gc/parallel/psCardTable.hpp"
#include "gc/parallel/psClosure.inline.hpp"
#include "gc/parallel/psPromotionManager.hpp"
#include "gc/parallel/psPromotionManager.inline.hpp"
#include "gc/parallel/psScavenge.inline.hpp"
#include "gc/parallel/psTasks.hpp"
#include "gc/shared/taskqueue.inline.hpp"
#include "memory/iterator.hpp"
#include "memory/resourceArea.hpp"
#include "memory/universe.hpp"
#include "oops/oop.inline.hpp"
#include "runtime/thread.hpp"
#include "runtime/vmThread.hpp"
#include "services/management.hpp"

//
// 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");

  while(true) {
    StarTask p;
    if (PSPromotionManager::steal_depth(which, 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");
}