conrad benham 20001 java opcode and runtime data analysis by: conrad benham supervisor: professor...

Conrad Benham 2000 1

Java Opcode and Runtime Data Analysis

By: Conrad Benham

Supervisor: Professor Arthur Sale


Project Goals

To collect data on Java’s:Opcodes,Runtime System andCreate a program to automate this.

These statistics will be used by Professor Sale to create an optimised Hardware Java Virtual Machine (JVM).


Why do this?- Competitive Analysis

Presently there are few JVMs implemented in hardware.

Existing implementations rarely have published documented to the level necessary for advanced research.

Java statistics are often difficult to obtain or sketchy in detail.


Why do this?- Research Analysis

Statistics will identify most common opcodes.

Allows hardware developers to focus on optimising a specific sub-set of the opcodes.

Findings will be published to help other research efforts.

Presently there are few tools which collect data of this kind.


So how does Java work?

Java Source CodeCreated by Java ProgrammerCreated by Java Programmer

Java CompilerProduces Java Byte CodesProduces Java Byte Codes

Platform Independent JVMRuns Java Byte CodesRuns Java Byte Codes

Go to Sun Microsystems’ Java web site at: www.java.sun.com

FOR MORE INFO...


What are we looking for?

Static Datacollected from the byte codes.collected from the byte codes.

does not change during execution time.does not change during execution time.

will change at compile time.will change at compile time.

Dynamic Datacollected at runtime.collected at runtime.

will change at runtime (depending on inputs will change at runtime (depending on inputs to a program).to a program).


Static Data

Includes data found in Java class files

e.g. the iadd instruction which adds e.g. the iadd instruction which adds two integer operands on the operand two integer operands on the operand stack together and pushes the result stack together and pushes the result back on the stack.back on the stack.

Branching InstructionsThe offset of instructions resulting from The offset of instructions resulting from the conditional statements (i.e. if, the conditional statements (i.e. if, while, switch, try).while, switch, try).


Types of Branching Instruction

Forwardi.e. if, else, switch and try.

Backwardi.e. loops such as for and whilei.e. loops such as for and while


Dynamic Data

Includes runtime analysise.g. average loop iterations, e.g. average loop iterations, processor usage, memory usage.processor usage, memory usage.

analysing feasibility of using registers, analysing feasibility of using registers, efficient heap allocation/de-allocation efficient heap allocation/de-allocation and garbage collection routines.and garbage collection routines.


Analysis Benchmarks

There are a number of benchmark suites available:

Including the Dhrystone and Whetstone Including the Dhrystone and Whetstone benchmarksbenchmarksBenchmark code must be:Benchmark code must be:• representative of most Java applications, they

must follow the typical programmers coding style

• able to test a JVM in terms of of how much system resources it uses (e.g processor usage and memory usage).


Method of Collection

Static DataSource Code CompilationSource Code Compilation

Class File DisassemblyClass File Disassembly

File ParsingFile Parsing

Dynamic DataNot finalisedNot finalised

Memory usage patternsMemory usage patterns

Execution timesExecution times

Other performance issuesOther performance issues


Demonstration


Conclusion

Relatively few organisations have collected data on Java, the emphasis is on code optimisation. The main aim of this project is to create and collect reusable components, data and statistics for other research.Comments and questions.

conrad benham 20001 java opcode and runtime data analysis by: conrad benham supervisor: professor...

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