/*

 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.

 * Copyright (c) 2017, Red Hat, Inc. and/or its affiliates.

 * 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 "gc/shared/gcArguments.hpp"

#include "runtime/arguments.hpp"

#include "runtime/globals.hpp"

#include "runtime/globals_extension.hpp"

#include "utilities/defaultStream.hpp"

#include "utilities/macros.hpp"

void GCArguments::initialize() {

  if (FullGCALot && FLAG_IS_DEFAULT(MarkSweepAlwaysCompactCount)) {

    MarkSweepAlwaysCompactCount = 1;  // Move objects every gc.

  }

  if (!(UseParallelGC || UseParallelOldGC) && FLAG_IS_DEFAULT(ScavengeBeforeFullGC)) {

    FLAG_SET_DEFAULT(ScavengeBeforeFullGC, false);

  }

  if (GCTimeLimit == 100) {

    // Turn off gc-overhead-limit-exceeded checks

    FLAG_SET_DEFAULT(UseGCOverheadLimit, false);

  }

  if (MinHeapFreeRatio == 100) {

    // Keeping the heap 100% free is hard ;-) so limit it to 99%.

    FLAG_SET_ERGO(uintx, MinHeapFreeRatio, 99);

  }

  if (!ClassUnloading) {

    // If class unloading is disabled, also disable concurrent class unloading.

    FLAG_SET_CMDLINE(bool, ClassUnloadingWithConcurrentMark, false);

  }

  if (!FLAG_IS_DEFAULT(AllocateOldGenAt)) {

    // CompressedOops not supported when AllocateOldGenAt is set.

    LP64_ONLY(FLAG_SET_DEFAULT(UseCompressedOops, false));

    LP64_ONLY(FLAG_SET_DEFAULT(UseCompressedClassPointers, false));

    // When AllocateOldGenAt is set, we cannot use largepages for entire heap memory.

    // Only young gen which is allocated in dram can use large pages, but we currently don't support that.

    FLAG_SET_DEFAULT(UseLargePages, false);

  }

}

bool GCArguments::check_args_consistency() {

  bool status = true;

  if (!FLAG_IS_DEFAULT(AllocateHeapAt) && !FLAG_IS_DEFAULT(AllocateOldGenAt)) {

    jio_fprintf(defaultStream::error_stream(),

      "AllocateHeapAt and AllocateOldGenAt cannot be used together.\n");

    status = false;

  }

  if (!FLAG_IS_DEFAULT(AllocateOldGenAt) && (UseSerialGC || UseConcMarkSweepGC || UseEpsilonGC || UseZGC)) {

    jio_fprintf(defaultStream::error_stream(),

      "AllocateOldGenAt is not supported for selected GC.\n");

    status = false;

  }

  return status;

}