/*

 * Copyright (c) 2000, 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/javaClasses.hpp"

#include "gc/shared/referencePolicy.hpp"

#include "memory/universe.hpp"

#include "runtime/arguments.hpp"

#include "runtime/globals.hpp"

LRUCurrentHeapPolicy::LRUCurrentHeapPolicy() {

  setup();

}

// Capture state (of-the-VM) information needed to evaluate the policy

void LRUCurrentHeapPolicy::setup() {

  _max_interval = (Universe::get_heap_free_at_last_gc() / M) * SoftRefLRUPolicyMSPerMB;

  assert(_max_interval >= 0,"Sanity check");

}

// The oop passed in is the SoftReference object, and not

// the object the SoftReference points to.

bool LRUCurrentHeapPolicy::should_clear_reference(oop p,

                                                  jlong timestamp_clock) {

  jlong interval = timestamp_clock - java_lang_ref_SoftReference::timestamp(p);

  assert(interval >= 0, "Sanity check");

  // The interval will be zero if the ref was accessed since the last scavenge/gc.

  if(interval <= _max_interval) {

    return false;

  }

  return true;

}

/////////////////////// MaxHeap //////////////////////

LRUMaxHeapPolicy::LRUMaxHeapPolicy() {

  setup();

}

// Capture state (of-the-VM) information needed to evaluate the policy

void LRUMaxHeapPolicy::setup() {

  size_t max_heap = MaxHeapSize;

  max_heap -= Universe::get_heap_used_at_last_gc();

  max_heap /= M;

  _max_interval = max_heap * SoftRefLRUPolicyMSPerMB;

  assert(_max_interval >= 0,"Sanity check");

}

// The oop passed in is the SoftReference object, and not

// the object the SoftReference points to.

bool LRUMaxHeapPolicy::should_clear_reference(oop p,

                                             jlong timestamp_clock) {

  jlong interval = timestamp_clock - java_lang_ref_SoftReference::timestamp(p);

  assert(interval >= 0, "Sanity check");

  // The interval will be zero if the ref was accessed since the last scavenge/gc.

  if(interval <= _max_interval) {

    return false;

  }

  return true;

}