voldemort.store.readonly.io
Class MemLock

java.lang.Object
  voldemort.store.readonly.io.MemLock

All Implemented Interfaces:

java.io.Closeable

public class MemLock
extends java.lang.Object
implements java.io.Closeable

Constructor Summary

MemLock(java.io.File file, java.io.FileDescriptor descriptor, long offset, long length)
Call mmap a file descriptor, then lock the pages with MAP_LOCKED.

Method Summary

void	close() Release this lock so that the memory can be returned to the OS if it wants to us it.
java.io.FileDescriptor	getDescriptor()
java.io.File	getFile()
void	setDescriptor(java.io.FileDescriptor descriptor)
void	setFile(java.io.File file)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MemLock

public MemLock(java.io.File file,
               java.io.FileDescriptor descriptor,
               long offset,
               long length)
        throws java.io.IOException

Call mmap a file descriptor, then lock the pages with MAP_LOCKED. This will then prevent the pages from being swapped out due to VFS cache pressure.

Parameters:

descriptor - The file we should mmap and MAP_LOCKED

offset -

length -

Throws:

java.io.IOException

See Also:

close()

Method Detail

close

public void close()
           throws java.io.IOException

Release this lock so that the memory can be returned to the OS if it wants to us it.

Specified by:

close in interface java.io.Closeable

Throws:

java.io.IOException

getFile

public java.io.File getFile()

setFile

public void setFile(java.io.File file)

getDescriptor

public java.io.FileDescriptor getDescriptor()

setDescriptor

public void setDescriptor(java.io.FileDescriptor descriptor)