Computation with time limit

Question

I\'m trying to write a construct which allows me to run computations in a given time window. Something like:

def expensiveComputation(): Double = //... some          


        

Answer 1

For a generic solution (without having to go litter each of your expensiveComputations with checkTimeout() code) perhaps use Javassist. http://www.csg.is.titech.ac.jp/~chiba/javassist/
You can then insert various checkTimeout() methods dynamically.
Here is the intro text on their website:

Javassist (Java Programming Assistant) makes Java bytecode manipulation simple. It is a class library for editing bytecodes in Java; it enables Java programs to define a new class at runtime and to modify a class file when the JVM loads it. Unlike other similar bytecode editors, Javassist provides two levels of API: source level and bytecode level. If the users use the source-level API, they can edit a class file without knowledge of the specifications of the Java bytecode. The whole API is designed with only the vocabulary of the Java language. You can even specify inserted bytecode in the form of source text; Javassist compiles it on the fly. On the other hand, the bytecode-level API allows the users to directly edit a class file as other editors.

Aspect Oriented Programming: Javassist can be a good tool for adding new methods into a class and for inserting before/after/around advice at the both caller and callee sides.

Reflection: One of applications of Javassist is runtime reflection; Javassist enables Java programs to use a metaobject that controls method calls on base-level objects. No specialized compiler or virtual machine are needed.