org.ojalgo.machine

Class Hardware

java.lang.Object

org.ojalgo.machine.BasicMachine

org.ojalgo.machine.Hardware

All Implemented Interfaces:

Comparable<Hardware>

public final class Hardware
extends BasicMachine
implements Comparable<Hardware>

• The first element in the array should correspond to total system resources; the total amount of RAM and the total number of threads (Typically the same as what is returned by Runtime.availableProcessors()).
• The last element in the array should describe the L1 cache. Typically Intel processors have 32k L1 cache and AMD 64k. 1 or maybe 2 threads use/share this cache.
• Caches, all levels except L1, are described between the first and last elements in descending order (L3 cache comes before L2 cache). Specify the size of the cache and the number of threads using/sharing the cache. (Do not worry about how many cache units there are - describe one unit.)
• The array must have at least 2 elements. You must describe the total system resources and the L1 cache. It is strongly recommended to also describe the L2 cache. The L3 cache, if it exists, is less important to describe. The derived attributes processors, cores and units may be incorrectly calculated if you fail to specify the caches. Known issue: If you have more than one processor, nut no L3 cache; the processors attribute will be incorrectly set 1. A workaround that currently works is to define an L3 cache anyway and set the memory/size of that cache to 0bytes. This workoround may stop working in the future.
• new MemoryThreads[] { SYSTEM, L3, L2, L1 } or new MemoryThreads[] { SYSTEM, L2, L1 } or new MemoryThreads[] { SYSTEM, L1 }

Author:

apete

Field Summary

Fields

Modifier and Type	Field and Description
String	architecture
long	cache The size of one top level (L3 or L2) cache unit in bytes.
int	cores The total number of processor cores.
static long	CPU_CACHE_LINE_SIZE Cache-line size is (typically) 64 bytes
static long	OS_MEMORY_PAGE_SIZE Practically all architectures/OS:s have a page size of 4k (one notable exception is Solaris/SPARC that have 8k)
static Set<Hardware>	PREDEFINED Should contain all available hardware in ascending "power" order.
int	units The number of top level (L3 or L2) cache units.

Fields inherited from class org.ojalgo.machine.BasicMachine

memory, threads

Constructor Summary

Constructors

Constructor and Description
Hardware(String architecture, BasicMachine[] levels) new BasicMachine[] { SYSTEM, L3, L2, L1 } or new BasicMachine[] { SYSTEM, L2, L1 } or in worst case new BasicMachine[] { SYSTEM, L1 }

Method Summary

Modifier and Type	Method and Description
int	compareTo(Hardware other)
IntCount	countCores()
IntCount	countThreads()
IntCount	countUnits()
boolean	equals(Object obj)
long	getCacheElements(long elementSize)
long	getMemoryElements(long elementSize)
int	hashCode()
boolean	isL2Specified()
boolean	isL3Specified()
boolean	isMultiCore()
boolean	isMultiThread()
boolean	isMultiUnit()
static Hardware	makeSimple()
static Hardware	makeSimple(String systemArchitecture, long systemMemory, int systemThreads)
String	toString()
VirtualMachine	virtualise()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

CPU_CACHE_LINE_SIZE

public static final long CPU_CACHE_LINE_SIZE

Cache-line size is (typically) 64 bytes

See Also:

Constant Field Values

OS_MEMORY_PAGE_SIZE

public static final long OS_MEMORY_PAGE_SIZE

Practically all architectures/OS:s have a page size of 4k (one notable exception is Solaris/SPARC that have 8k)

See Also:

Constant Field Values

PREDEFINED

public static final Set<Hardware> PREDEFINED

Should contain all available hardware in ascending "power" order.

architecture

public final String architecture

cache

public final long cache

The size of one top level (L3 or L2) cache unit in bytes.

cores

public final int cores

The total number of processor cores.

units

public final int units

The number of top level (L3 or L2) cache units.

Constructor Detail

Hardware

public Hardware(String architecture,
                BasicMachine[] levels)

new BasicMachine[] { SYSTEM, L3, L2, L1 } or new BasicMachine[] { SYSTEM, L2, L1 } or in worst case new BasicMachine[] { SYSTEM, L1 }

Method Detail

makeSimple

public static Hardware makeSimple()

makeSimple

public static Hardware makeSimple(String systemArchitecture,
                                  long systemMemory,
                                  int systemThreads)

compareTo

public int compareTo(Hardware other)

Specified by:

compareTo in interface Comparable<Hardware>

equals

public boolean equals(Object obj)

hashCode

public int hashCode()

isL2Specified

public boolean isL2Specified()

isL3Specified

public boolean isL3Specified()

toString

public String toString()

Overrides:

toString in class BasicMachine

virtualise

public VirtualMachine virtualise()

countCores

public IntCount countCores()

countThreads

public IntCount countThreads()

countUnits

public IntCount countUnits()

getCacheElements

public long getCacheElements(long elementSize)

getMemoryElements

public long getMemoryElements(long elementSize)

isMultiCore

public boolean isMultiCore()

isMultiThread

public boolean isMultiThread()

isMultiUnit

public boolean isMultiUnit()