-
Notifications
You must be signed in to change notification settings - Fork 2.3k
/
VictimPageReference.java
47 lines (43 loc) · 1.69 KB
/
VictimPageReference.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
/*
* Copyright (c) 2002-2018 "Neo Technology,"
* Network Engine for Objects in Lund AB [http://neotechnology.com]
*
* This file is part of Neo4j.
*
* Neo4j is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.neo4j.io.pagecache.impl.muninn;
import org.neo4j.memory.MemoryAllocationTracker;
import org.neo4j.unsafe.impl.internal.dragons.UnsafeUtil;
class VictimPageReference
{
private static int victimPageSize = -1;
private static long victimPagePointer;
private VictimPageReference()
{
// All state is static
}
static synchronized long getVictimPage( int pageSize, MemoryAllocationTracker allocationTracker )
{
if ( victimPageSize < pageSize )
{
// Note that we NEVER free any old victim pages. This is important because we cannot tell
// when we are done using them. Therefor, victim pages are allocated and stay allocated
// until our process terminates.
victimPagePointer = UnsafeUtil.allocateMemory( pageSize, allocationTracker );
victimPageSize = pageSize;
}
return victimPagePointer;
}
}