org.apache.flink.runtime.io.network.partition

Class PageSizeUtil

java.lang.Object

org.apache.flink.runtime.io.network.partition.PageSizeUtil

public final class PageSizeUtil
extends Object

Utility for accessing the system page size.

Field Summary

Fields

Modifier and Type	Field and Description
static int	CONSERVATIVE_PAGE_SIZE_MULTIPLE A conservative fallback value (64 KiBytes) that should be a multiple of the page size even in some uncommon cases of servers installations with larger-than-usual page sizes.
static int	DEFAULT_PAGE_SIZE The default page size on most systems.
static int	PAGE_SIZE_UNKNOWN Value indicating an unknown page size.

Method Summary

Modifier and Type	Method and Description
static int	getSystemPageSize() Tries to get the system page size.
static int	getSystemPageSizeOrConservativeMultiple() Tries to get the system page size.
static int	getSystemPageSizeOrDefault() Tries to get the system page size.

Methods inherited from class java.lang.Object

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

Field Detail

PAGE_SIZE_UNKNOWN

public static final int PAGE_SIZE_UNKNOWN

Value indicating an unknown page size.

See Also:

Constant Field Values

DEFAULT_PAGE_SIZE

public static final int DEFAULT_PAGE_SIZE

The default page size on most systems.

See Also:

Constant Field Values

CONSERVATIVE_PAGE_SIZE_MULTIPLE

public static final int CONSERVATIVE_PAGE_SIZE_MULTIPLE

A conservative fallback value (64 KiBytes) that should be a multiple of the page size even in some uncommon cases of servers installations with larger-than-usual page sizes.

See Also:

Constant Field Values

Method Detail

getSystemPageSize

public static int getSystemPageSize()

Tries to get the system page size. If the page size cannot be determined, this returns -1.

This internally relies on the presence of "unsafe" and the resolution via some Netty utilities.

getSystemPageSizeOrDefault

public static int getSystemPageSizeOrDefault()

Tries to get the system page size. If the page size cannot be determined, this returns the DEFAULT_PAGE_SIZE.

getSystemPageSizeOrConservativeMultiple

public static int getSystemPageSizeOrConservativeMultiple()

Tries to get the system page size. If the page size cannot be determined, this returns the CONSERVATIVE_PAGE_SIZE_MULTIPLE.