Find a way to not load all the function stubs up-front #22

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krestenkrab opened this Issue Mar 6, 2010 · 3 comments

2 participants

@krestenkrab
Trifork member

I suspect we spend a lot of time loading function stubs for all function (specialized java.lang.reflect.Method-like things) when Erjang launches. Establish the truth in that statement; and then figure out if we can somehow make that lazy.

Every exported function needs one of these stubs (some subclass of EFun), but perhaps we can install a generic handler which will then replace itself when invoked the first time. Ideally, we should only need to load 1 class per module (until you start calling functions).

@krestenkrab
Trifork member

I looked at some numbers for some of the modules. 2 samples, application_controller: the main modules takes 47% of the java byte codes; for erl_parse the main module takes only 35% of the java byte code. The more functions a module has, the smaller the fraction is typically "real stuff".

It's an issue for us that we use too much memory on JVM byte codes.

@eriksoe

I've changed function wrapper generation so that the function classes are simpler.
This brings the figures to (for R14A):
application_controller: 64% is main module
erl_parse: 42% is main module
An improvement (and estone numbers weren't affected by the change).
At the same time, the cache size was reduced by 15%.
Not sure whether Java process footprint has improved though.

@krestenkrab
Trifork member

I think we'll move this to the day we do InvokeDynamic. Closing for now.

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