1 /*

     2  * Copyright 2000-2003 Sun Microsystems, Inc.  All Rights Reserved.

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

     4  *

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

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

     7  * published by the Free Software Foundation.

     8  *

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

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

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

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

    13  * accompanied this code).

    14  *

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

    16  * 2 along with this work; if not, write to the Free Software Foundation,

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

    18  *

    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  *

    23  */

    24 

    25 # include "incls/_precompiled.incl"

    26 # include "incls/_referencePolicy.cpp.incl"

    27 

    28 LRUCurrentHeapPolicy::LRUCurrentHeapPolicy() {

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

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

    31 }

    32 

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

    34 // the object the SoftReference points to.

    35 bool LRUCurrentHeapPolicy::should_clear_reference(oop p) {

    36   jlong interval = java_lang_ref_SoftReference::clock() - java_lang_ref_SoftReference::timestamp(p);

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

    38 

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

    40   if(interval <= _max_interval) {

    41     return false;

    42   }

    43 

    44   return true;

    45 }

    46 

    47 /////////////////////// MaxHeap //////////////////////

    48 

    49 LRUMaxHeapPolicy::LRUMaxHeapPolicy() {

    50   size_t max_heap = MaxHeapSize;

    51   max_heap -= Universe::get_heap_used_at_last_gc();

    52   max_heap /= M;

    53 

    54   _max_interval = max_heap * SoftRefLRUPolicyMSPerMB;

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

    56 }

    57 

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

    59 // the object the SoftReference points to.

    60 bool LRUMaxHeapPolicy::should_clear_reference(oop p) {

    61   jlong interval = java_lang_ref_SoftReference::clock() - java_lang_ref_SoftReference::timestamp(p);

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

    63 

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

    65   if(interval <= _max_interval) {

    66     return false;

    67   }

    68 

    69   return true;

    70 }