[ruby-core:95353] [Ruby master Feature#16245] Add interfaces to count and measure size all IMEMO objects

[ko1@atdot.net]

Issue #16245 has been updated by ko1 (Koichi Sasada).


Already we have:

```ruby
require 'objspace'
pp ObjectSpace.count_imemo_objects
#=>
{:imemo_env=>42,
 :imemo_cref=>177,
 :imemo_ment=>3662,
 :imemo_iseq=>1194,
 :imemo_tmpbuf=>117,
 :imemo_ast=>22,
 :imemo_svar=>40,
 :imemo_throw_data=>55,
 :imemo_ifunc=>35,
 :imemo_memo=>32,
 :imemo_parser_strterm=>118}
```

There is no size version. do you want to introduce it?



----------------------------------------
Feature #16245: Add interfaces to count and measure size all IMEMO objects
https://bugs.ruby-lang.org/issues/16245#change-82061

* 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?



-- 
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