| [henshin-dev] Performance tweaks |
Hi everybody,I am currently profiling the state space generation tool and try to tweak the performance as much as possible. A critical parameter for the performance is the memory usage. There are two kinds of used memory: (1) cached objects / models which are used to speed up the look up for states, and (2) transient objects which are generated and "destroyed" on the fly and used in methods to store some intermediate information.
I believe that (2) is a critical point for the performance of the state space generation tool, and maybe also the interpreter itself. The problem is that a number of objects are created, e.g. maps, lists etc. which are used only once. All these objects have to be garbage collected which slows down the state space generation significantly.
We should be able to improve the situation by creating only transient objects when it is really necessary. Instead, we should try to cache as much objects as possible.
I am currently caching the InterpreterEngines I use for the state space generation. My feeling is that the caching inside the engine and the match finder can be also improved. We should always assume that an engine instance is not used concurrently. Under this premiss it should be possible to cache more objects, e.g. AttributeConditionHandlers or copied TransformationOptions in the engine. Storing such objects in a hash map should allow us to make the memory usage more stable (less transient objects). I know that the lookup in the hashmaps also takes some time, but I believe that for the end performance it has a positive effect.
Is somebody of the interpreter developers interested in trying to tweak the memory footprint for transient object / performance in this direction? I really think that we can gain a speed up here.
Cheers, Christian