Package org.apache.hadoop.util

Class CleanerUtil

java.lang.Object

org.apache.hadoop.util.CleanerUtil

@Private
@Unstable
public final class CleanerUtil
extends Object

sun.misc.Cleaner has moved in OpenJDK 9 and sun.misc.Unsafe#invokeCleaner(ByteBuffer) is the replacement. This class is a hack to use sun.misc.Cleaner in Java 8 and use the replacement in Java 9+. This implementation is inspired by LUCENE-6989.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	CleanerUtil.BufferCleaner	Pass in an implementation of this interface to cleanup ByteBuffers.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	UNMAP_NOT_SUPPORTED_REASON	if UNMAP_SUPPORTED is false, this contains the reason why unmapping is not supported.
static final boolean	UNMAP_SUPPORTED	true, if this platform supports unmapping mmapped files.

Method Summary

Modifier and Type	Method	Description
static CleanerUtil.BufferCleaner	getCleaner()	Reference to a BufferCleaner that does unmapping.

Methods inherited from class java.lang.Object

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

Field Details

UNMAP_SUPPORTED

public static final boolean UNMAP_SUPPORTED

true, if this platform supports unmapping mmapped files.

UNMAP_NOT_SUPPORTED_REASON

public static final String UNMAP_NOT_SUPPORTED_REASON

if UNMAP_SUPPORTED is false, this contains the reason why unmapping is not supported.

Method Details

getCleaner

public static CleanerUtil.BufferCleaner getCleaner()

Reference to a BufferCleaner that does unmapping.

Returns:

null if not supported.