com.azul.zing.management

Class MemoryUsage

java.lang.Object

com.azul.zing.management.MemoryUsage

public class MemoryUsage
extends java.lang.Object

A memory pool usage snapshot with sizes and the time the snapshot was taken.

A MemoryUsage object has the following fields to make tracking memory pool sizes easier:

memoryPoolSizeType	The MemoryPoolSizeType of the memory pool.
initialReserved	The amount of memory initially reserved for the memory pool when it was created.
size	The amount of memory, both used and unused, currently in the memory pool.
used	The amount of memory currently in use in the memory pool.
elapsedTimeSinceJVMStartSec	The wall clock time at which the MemoryUsage object was created in units of elapsed seconds since the start of the JVM.

Constructor Summary

Constructors

Constructor and Description
MemoryUsage(MemoryPoolSizeType memoryPoolSizeType, long initialReserved, long size, long used, double elapsedTimeSinceJVMStartSec) Constructs a new MemoryUsage instance using the enumerated type for the size type.

Method Summary

Methods

Modifier and Type	Method and Description
static MemoryUsage	from(javax.management.openmbean.CompositeData cd) Constructs a MemoryUsage object from the CompositeData passed.
double	getElapsedTimeSinceJVMStartSec() Returns the wall clock time at which the MemoryUsage object was created in units of elapsed seconds since the start of the JVM.
long	getInitialReserved() Returns the amount of memory initially reserved in bytes for the memory pool used as the basis for creating this MemoryUsage object.
MemoryPoolSizeType	getMemoryPoolSizeType() Returns the MemoryPoolSizeType for the memory pool used as the basis for creating this MemoryUsage object.
long	getSize() Returns the approximate amount of memory in bytes that the memory pool currently occupies, both used and unused, when this MemoryUsage object was created.
long	getUsed() Returns the approximate amount of memory in bytes in use in the memory pool when this MemoryUsage object was created.
java.lang.String	toString() Returns a String object with the information describing this MemoryUsage object.

Methods inherited from class java.lang.Object

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

Constructor Detail

MemoryUsage

public MemoryUsage(MemoryPoolSizeType memoryPoolSizeType,
           long initialReserved,
           long size,
           long used,
           double elapsedTimeSinceJVMStartSec)

Constructs a new MemoryUsage instance using the enumerated type for the size type.

Parameters:

memoryPoolSizeType - The size type of the memory pool, whether it is a fixed size or can expand or contract in size. See MemoryPoolSizeType for valid values.

initialReserved - The amount of memory reserved for this memory pool when the memory pool was originally created (bytes).

size - The sum of the current used plus the current unused memory for this memory pool (bytes).

used - The amount of memory used (bytes).

elapsedTimeSinceJVMStartSec - The time when this MemoryUsage object was created with units in seconds since the start of the JVM.

Throws:

java.lang.IllegalArgumentException - if initialReserved, size or used is less than 0 or used is greater than size.

Method Detail

from

public static MemoryUsage from(javax.management.openmbean.CompositeData cd)

Constructs a MemoryUsage object from the CompositeData passed.

The CompositeData input parameter must contain the following values:

Attribute Name	Type
MemoryPoolSizeType	java.lang.String
initialReserved	java.lang.Long
size	java.lang.Long
used	java.lang.Long
elapsedTimeSinceJVMStartSec	java.lang.Double

Parameters:

cd - The CompositeData object from which to retrieve the required MemoryUsage values.

Returns:

MemoryUsage object with the cd data values; null otherwise.

Throws:

java.lang.IllegalArgumentException - if cd does not contain MemoryUsage data.

getElapsedTimeSinceJVMStartSec

public double getElapsedTimeSinceJVMStartSec()

Returns the wall clock time at which the MemoryUsage object was created in units of elapsed seconds since the start of the JVM.

Returns:

time at which the MemoryUsage object was created in units of elapsed seconds since the start of the JVM.

getInitialReserved

public long getInitialReserved()

Returns the amount of memory initially reserved in bytes for the memory pool used as the basis for creating this MemoryUsage object.

Returns:

amount of memory initially reserved in bytes for this MemoryUsage object.

getMemoryPoolSizeType

public MemoryPoolSizeType getMemoryPoolSizeType()

Returns the MemoryPoolSizeType for the memory pool used as the basis for creating this MemoryUsage object.

Returns:

MemoryPoolSizeType for this MemoryUsage object.

getSize

public long getSize()

Returns the approximate amount of memory in bytes that the memory pool currently occupies, both used and unused, when this MemoryUsage object was created. The value returned by getUsed() is expected to always be less than or equal to the value returned by getSize.

Returns:

amount of memory in bytes that the memory pool currently occupies, both used and unused.

getUsed

public long getUsed()

Returns the approximate amount of memory in bytes in use in the memory pool when this MemoryUsage object was created. The value returned by getSize() is expected to always be greater than or equal to the value returned by getUsed.

Returns:

amount of memory in bytes in use in the memory pool.

toString

public java.lang.String toString()

Returns a String object with the information describing this MemoryUsage object.

Overrides:

toString in class java.lang.Object

Returns:

String describing this MemoryUsage object.