From: "peterzhu2118 (Peter Zhu) via ruby-core" <ruby-core@...>
Date: 2024-07-24T19:19:48+00:00
Subject: [ruby-core:118680] [Ruby master Bug#20650] Memory leak in Regexp capture group when timeout

Issue #20650 has been reported by peterzhu2118 (Peter Zhu).

----------------------------------------
Bug #20650: Memory leak in Regexp capture group when timeout
https://bugs.ruby-lang.org/issues/20650

* Author: peterzhu2118 (Peter Zhu)
* Status: Open
* Backport: 3.1: UNKNOWN, 3.2: REQUIRED, 3.3: REQUIRED
----------------------------------------
GitHub PR: https://github.com/ruby/ruby/pull/11238

The capture group allocates memory that is leaked when it times out.

For example:

```ruby
re = Regexp.new("^#{"(a*)" * 10_000}x$", timeout: 0.000001)
str = "a" * 1000000 + "x"

10.times do
  100.times do
    re =~ str
  rescue Regexp::TimeoutError
  end

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

Before:

```
34688
56416
78288
100368
120784
140704
161904
183568
204320
224800
```

After:

```
16288
16288
16880
16896
16912
16928
16944
17184
17184
17200
```



-- 
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