RJAVA

RJAVA is JVM made for fun on Rust.

Very. Limited. JVM

However, it may do some tricks other JVMs cannot do.

How to use

cd examples
cargo build --release
javac YourClass.java
cargo run --release YourClass

Tail Recursion optimization

See examples/TailRecursion.java

cd examples
javac TailRecursion.java
cargo run --release TailRecursion

Check timings and rjava.log - it will contain dump of stack and heap.

Annotation @RVM.TailRecursion is specially processed by RJAVA. It turns recursive call into 'loop'.

Memoization

See examples/Memorize.java

cd examples
javac Memorize.java
cargo run --release Memorize

Check timings and rjava.log.

Annotation @RVM.Mem leads to caching of method call results using io.github.rvm.MemEntry class. Instances of that class are created internally when needed, you may see it in heap.

AutoFree

See examples/AutoFree.java

cd examples
javac AutoFree.java
cargo run --release AutoFree

Check output and rjava.log.

RJAVA does not have GC. But when method is annotated with @RVM.AutoFree, then all objects instantiated with new in this stack frame and all deeper frames will be automatically removed from memory.

It means that references to objects/arrays could be passed "down" through stack, but not "up" (as they became invalid).

What is the day today?

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( It's Wednesday, my Java dudes! )
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