visualizing objects and memory usage

Visualizing Objects and

Memory Usage

RMod

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I n g . m a r i a n o m a r t i n e z p e c km a r i a n o p e c k @ g m a i l . c o m

Saturday, November 13, 2010

mailto:[email protected]


The context

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1st step: UNDERSTAND.

To understand: VISUALIZATIONS.

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Problem

How to visualize objects and memory usage.

Special treatment for classes, methods and packages.

Take into account objects usage.

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Regarding related work...no one solves the problem of

taking into account objects usage.

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Our solution

Trace objects usage.

Use DistributionMaps to visualize the results.

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Moose is a platform for software and data analysis


DistributionMap“Distribution Map visualizes parts of a system and shows how properties of the part elements spread over the initial parts. ”

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part 1 part 2 part 3

part 4part 5

Container

Element

Property1Property2Property3Property4


JBOSS example

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Used Object Maps

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Distribution Maps that take into account objects and memory usage


How to use them?

1.Start the analysis.

2.Run the scenario to analyze.

3.Stop the analysis.

4.Visualize using DistributionMaps.

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SHOWTIME

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Tracing Objects Usage

Usage bit in the Object Header (Virtual Machine).

Define “when an objects is marked as used?”.

Modify VM to mark objects when used.

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when an objects is marked as used?

Quick answer: when it receives a message.

When the VM directly use it.

When used by special VM bytecodes (#class, #==, etc).

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Showtime 2

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Possible uses

When building minimal images.

Virtual memory implementations.

Detect bad smells or possible overuse of memory.

Detect opportunities of refactorings.

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conclusions and future work

Use Distribution Maps and distinguish between used and unused instances.

Useful to analyze the system and to know which objects are used in different scenarios.

DistributionMap comparator.


Thanks!

Mariano Martinez [email protected]

RMod




visualizing objects and memory usage

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