net.sf.ehcache.pool.sizeof
Enum JvmInformation

java.lang.Object
  java.lang.Enum<JvmInformation>
      net.sf.ehcache.pool.sizeof.JvmInformation

All Implemented Interfaces:

Serializable, Comparable<JvmInformation>

public enum JvmInformation
extends Enum<JvmInformation>

Detects and represents JVM-specific properties that relate to the memory data model for java objects that are useful for size of calculations.

Author:

jhouse, Chris Dennis

Enum Constant Summary

HOTSPOT_32_BIT
Represents HotSpot 32-bit

HOTSPOT_32_BIT_WITH_CONCURRENT_MARK_AND_SWEEP
Represents 32-Bit HotSpot JVM with Concurrent Mark-and-Sweep GC

HOTSPOT_64_BIT
Represents 64-Bit HotSpot JVM

HOTSPOT_64_BIT_WITH_COMPRESSED_OOPS
Represents 64-Bit HotSpot JVM with Compressed OOPs

HOTSPOT_64_BIT_WITH_COMPRESSED_OOPS_AND_CONCURRENT_MARK_AND_SWEEP
Represents 64-Bit HotSpot JVM with Compressed OOPs and Concurrent Mark-and-Sweep GC

HOTSPOT_64_BIT_WITH_CONCURRENT_MARK_AND_SWEEP
Represents 64-Bit HotSpot JVM with Concurrent Mark-and-Sweep GC

IBM_32_BIT
Represents IBM 32-bit

IBM_64_BIT
Represents 64-Bit IBM JVM (with no reference compression)

IBM_64_BIT_WITH_COMPRESSED_REFS
Represents 64-Bit IBM JVM (with reference compression)

JROCKIT_32_BIT
Represents 32-Bit JRockit JVM"

JROCKIT_64_BIT
Represents 64-Bit JRockit JVM (with no reference compression)

JROCKIT_64_BIT_WITH_32GB_COMPRESSED_REFS
Represents 64-Bit JRockit JVM with 32GB Compressed References

JROCKIT_64_BIT_WITH_4GB_COMPRESSED_REFS
Represents 64-Bit JRockit JVM with 4GB Compressed References

JROCKIT_64_BIT_WITH_64GB_COMPRESSED_REFS
Represents 64-Bit JRockit JVM with 64GB Compressed References

UNKNOWN_32_BIT
Represents Generic 32-bit

UNKNOWN_64_BIT
Represents 64-Bit Generic JVM

Field Summary

static JvmInformation

CURRENT_JVM_INFORMATION The JvmInformation instance representing the current JVM

Method Summary

int	getAgentSizeOfAdjustment() The size of the jvm-specific agent result adjustment in bytes.
int	getFieldOffsetAdjustment() The size of the jvm-specific field offset adjustment in bytes.
abstract int	getJavaPointerSize() Size of a java pointer in bytes on this runtime (that differs when compressedOops are being used)
abstract String	getJvmDescription() A human-readable description of the JVM and its relevant enabled options.Os
int	getMinimumObjectSize() Minimal size an object will occupy on the heap in bytes.
int	getObjectAlignment() Object alignment / padding in bytes
int	getObjectHeaderSize() The size of an object header in bytes.
abstract int	getPointerSize() Size of a pointer in bytes on this runtime
static boolean	isHotspot() Returns true if VM vendor is Hotspot
static boolean	isIBM() Returns true if VM vendor is IBM
static boolean	isJRockit() Returns true if VM is JRockit
static boolean	isOSX() Return true if the VM's vendor is Apple
boolean	supportsAgentSizeOf() Whether the jvm can support AgentSizeOf implementation.
boolean	supportsReflectionSizeOf() Whether the jvm can support ReflectionSizeOf implementation.
boolean	supportsUnsafeSizeOf() Whether the jvm can support UnsafeSizeOf implementation.
static JvmInformation	valueOf(String name) Returns the enum constant of this type with the specified name.
static JvmInformation[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

HOTSPOT_32_BIT

public static final JvmInformation HOTSPOT_32_BIT

Represents HotSpot 32-bit

HOTSPOT_32_BIT_WITH_CONCURRENT_MARK_AND_SWEEP

public static final JvmInformation HOTSPOT_32_BIT_WITH_CONCURRENT_MARK_AND_SWEEP

Represents 32-Bit HotSpot JVM with Concurrent Mark-and-Sweep GC

HOTSPOT_64_BIT

public static final JvmInformation HOTSPOT_64_BIT

Represents 64-Bit HotSpot JVM

HOTSPOT_64_BIT_WITH_CONCURRENT_MARK_AND_SWEEP

public static final JvmInformation HOTSPOT_64_BIT_WITH_CONCURRENT_MARK_AND_SWEEP

Represents 64-Bit HotSpot JVM with Concurrent Mark-and-Sweep GC

HOTSPOT_64_BIT_WITH_COMPRESSED_OOPS

public static final JvmInformation HOTSPOT_64_BIT_WITH_COMPRESSED_OOPS

Represents 64-Bit HotSpot JVM with Compressed OOPs

HOTSPOT_64_BIT_WITH_COMPRESSED_OOPS_AND_CONCURRENT_MARK_AND_SWEEP

public static final JvmInformation HOTSPOT_64_BIT_WITH_COMPRESSED_OOPS_AND_CONCURRENT_MARK_AND_SWEEP

Represents 64-Bit HotSpot JVM with Compressed OOPs and Concurrent Mark-and-Sweep GC

JROCKIT_32_BIT

public static final JvmInformation JROCKIT_32_BIT

Represents 32-Bit JRockit JVM"

JROCKIT_64_BIT

public static final JvmInformation JROCKIT_64_BIT

Represents 64-Bit JRockit JVM (with no reference compression)

JROCKIT_64_BIT_WITH_4GB_COMPRESSED_REFS

public static final JvmInformation JROCKIT_64_BIT_WITH_4GB_COMPRESSED_REFS

Represents 64-Bit JRockit JVM with 4GB Compressed References

JROCKIT_64_BIT_WITH_32GB_COMPRESSED_REFS

public static final JvmInformation JROCKIT_64_BIT_WITH_32GB_COMPRESSED_REFS

Represents 64-Bit JRockit JVM with 32GB Compressed References

JROCKIT_64_BIT_WITH_64GB_COMPRESSED_REFS

public static final JvmInformation JROCKIT_64_BIT_WITH_64GB_COMPRESSED_REFS

Represents 64-Bit JRockit JVM with 64GB Compressed References

IBM_64_BIT_WITH_COMPRESSED_REFS

public static final JvmInformation IBM_64_BIT_WITH_COMPRESSED_REFS

Represents 64-Bit IBM JVM (with reference compression)

IBM_64_BIT

public static final JvmInformation IBM_64_BIT

Represents 64-Bit IBM JVM (with no reference compression)

IBM_32_BIT

public static final JvmInformation IBM_32_BIT

Represents IBM 32-bit

UNKNOWN_32_BIT

public static final JvmInformation UNKNOWN_32_BIT

Represents Generic 32-bit

UNKNOWN_64_BIT

public static final JvmInformation UNKNOWN_64_BIT

Represents 64-Bit Generic JVM

Field Detail

CURRENT_JVM_INFORMATION

public static final JvmInformation CURRENT_JVM_INFORMATION

The JvmInformation instance representing the current JVM

Method Detail

values

public static JvmInformation[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (JvmInformation c : JvmInformation.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static JvmInformation valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

getPointerSize

public abstract int getPointerSize()

Size of a pointer in bytes on this runtime

getJavaPointerSize

public abstract int getJavaPointerSize()

Size of a java pointer in bytes on this runtime (that differs when compressedOops are being used)

getMinimumObjectSize

public int getMinimumObjectSize()

Minimal size an object will occupy on the heap in bytes.

getObjectAlignment

public int getObjectAlignment()

Object alignment / padding in bytes

getObjectHeaderSize

public int getObjectHeaderSize()

The size of an object header in bytes.

getFieldOffsetAdjustment

public int getFieldOffsetAdjustment()

The size of the jvm-specific field offset adjustment in bytes.

getAgentSizeOfAdjustment

public int getAgentSizeOfAdjustment()

The size of the jvm-specific agent result adjustment in bytes.

supportsAgentSizeOf

public boolean supportsAgentSizeOf()

Whether the jvm can support AgentSizeOf implementation.

supportsUnsafeSizeOf

public boolean supportsUnsafeSizeOf()

Whether the jvm can support UnsafeSizeOf implementation.

supportsReflectionSizeOf

public boolean supportsReflectionSizeOf()

Whether the jvm can support ReflectionSizeOf implementation.

getJvmDescription

public abstract String getJvmDescription()

A human-readable description of the JVM and its relevant enabled options.Os

isJRockit

public static boolean isJRockit()

Returns true if VM is JRockit

Returns:

true, if JRockit

isOSX

public static boolean isOSX()

Return true if the VM's vendor is Apple

Returns:

true, if OS X

isHotspot

public static boolean isHotspot()

Returns true if VM vendor is Hotspot

Returns:

true, if Hotspot

isIBM

public static boolean isIBM()

Returns true if VM vendor is IBM

Returns:

true, if IBM