From: "nagachika (Tomoyuki Chikanaga) via ruby-core" <ruby-core@...>
Date: 2024-07-07T05:51:14+00:00
Subject: [ruby-core:118471] [Ruby master Bug#20145] Memory leak when duplicating identhash

Issue #20145 has been updated by nagachika (Tomoyuki Chikanaga).

Backport changed from 3.0: UNKNOWN, 3.1: REQUIRED, 3.2: REQUIRED, 3.3: DONE to 3.1: WONTFIX, 3.2: WONTFIX, 3.3: DONE

My trial backpoting to ruby_3_2 introduce Segmentation fault. See https://github.com/nagachika/ruby/actions/runs/9824962371/job/27124518333
I gave up to backport this to ruby_3_2.

----------------------------------------
Bug #20145: Memory leak when duplicating identhash
https://bugs.ruby-lang.org/issues/20145#change-108985

* Author: peterzhu2118 (Peter Zhu)
* Status: Closed
* Backport: 3.1: WONTFIX, 3.2: WONTFIX, 3.3: DONE
----------------------------------------
GitHub PR: https://github.com/ruby/ruby/pull/9411

Both copy_compare_by_id and hash_copy will create a copy of the ST table, so the ST table created in copy_compare_by_id will be leaked.

```ruby
h = { 1 => 2 }.compare_by_identity

10.times do
  1_000_000.times do
    h.select { false }
  end

  puts `ps -o rss= -p #{$$}`
end
```

Before:

```
110736
204352
300272
395520
460704
476736
542000
604704
682624
770528
```

After:

```
15504
16048
16144
16256
16320
16320
16752
16752
16752
16752
```



-- 
https://bugs.ruby-lang.org/
 ______________________________________________
 ruby-core mailing list -- ruby-core@ml.ruby-lang.org
 To unsubscribe send an email to ruby-core-leave@ml.ruby-lang.org
 ruby-core info -- https://ml.ruby-lang.org/mailman3/lists/ruby-core.ml.ruby-lang.org/