[ruby-core:95281] [Ruby master Feature#16245] Add interfaces to count and measure size all IMEMO objects

[shevegen@gmail.com]

Issue #16245 has been updated by shevegen (Robert A. Heiler).


Personally I love introspection so I am all in favour of giving ruby people
lots of tools to play with internal. I also liked oldschool evi.rb. :)

I guess this is for koichi to comment e. g. how stable he considers the 
gem/code; and possibly also whether the API is wanted in the first place.
And perhaps also whether the name iseq is already an official name or
not, ruby-internal wise (I really don't know, just pointing that out).

As for the name **NonMaterializedInstructionSequences** - I think that name is
too long and complicated. Ideally accessing should be simple, whenever possible,
in my opinion. I am not even sure what a "non-materialized instruction sequence"
is - is that ruby's version of a monoid-endofunctor monad?

IMO, simpler names would be better. Although I guess if the functionality is
what matters, then I guess we may agree that the functionality can be useful.

methodmissing wrote:

> I understand the API proposal, but also I believe the intention was for these
> objects to be internal and not necessarily to be exposed through API. 

Yeah, I think I have read similar discussions in the past, also comments made
by matz, koichi and shyouhei, in a different context. Which I guess makes 
sense too - less exposure may mean less problems. I am also neutral about the
proposal really, don't mind either way - guess it may be for sam to reason
in favour of it. :-)

Even then, though, I love introspection in general. Ruby is like a closed box
initially, just like on xmas (and the xmas release), and you get the tools to
poke inside and try to find out how it works! \o/

Perhaps if it may help the discussion (not that I contribute much to it), 
there could be a discussion for potential problems in this regard, e. g.
pitfalls, problems etc... or it may remain a separate gem, and it may be
evaluated how useful it may be to integrate it into ruby directly. That 
discussion has also happened with other code elements / gems in the past,
e. g. martin duerst pointed this out a few times before. But as said, I
am really neutral either way here.

----------------------------------------
Feature #16245: Add interfaces to count and measure size all IMEMO objects
https://bugs.ruby-lang.org/issues/16245#change-81959

* Author: sam.saffron (Sam Saffron)
* Status: Open
* Priority: Normal
* Assignee: 
* Target version: 
----------------------------------------
Koichi introduced an experimental gem: https://github.com/ko1/iseq_collector

It allows:

ObjectSpace.each_iseq{|iseq| ...}
ObjectSpace.count_iseq #=> Integer
ObjectSpace.memsize_of_all_iseq (should not generate RubyVM::InstructionSequence wrappers for IMEMOs)

Since the wrapper object  RubyVM::InstructionSequence is lazily allocated, ObjectSpace.each_object does not find these IMEMOs unless they have been wrapped. This design is good and conserves memory. 

`count_iseq` and `memsize_of_all_iseq` are very powerful metrics most large Ruby deployments can use to automatically detect method leaks introduced via meta programming. These issues are invisible now short of walking a heap dump. 

Can we add the new interface into 2.7?



-- 
https://bugs.ruby-lang.org/