[#116016] [Ruby master Bug#20150] Memory leak in grapheme clusters — "peterzhu2118 (Peter Zhu) via ruby-core" <ruby-core@...>
Issue #20150 has been reported by peterzhu2118 (Peter Zhu).
7 messages
2024/01/04
[#116382] [Ruby master Feature#20205] Enable `frozen_string_literal` by default — "byroot (Jean Boussier) via ruby-core" <ruby-core@...>
Issue #20205 has been reported by byroot (Jean Boussier).
77 messages
2024/01/23
[ruby-core:116022] [Ruby master Bug#20104] Regexp#match returns nil but allocates T_MATCH objects
From:
"jeremyevans0 (Jeremy Evans) via ruby-core" <ruby-core@...>
Date:
2024-01-04 23:43:06 UTC
List:
ruby-core #116022
Issue #20104 has been updated by jeremyevans0 (Jeremy Evans).
Status changed from Open to Closed
This is already marked for backport to 3.3, it just needs to be closed.
----------------------------------------
Bug #20104: Regexp#match returns nil but allocates T_MATCH objects
https://bugs.ruby-lang.org/issues/20104#change-106012
* Author: jeremyevans0 (Jeremy Evans)
* Status: Closed
* Priority: Normal
* ruby -v: ruby 3.4.0dev (2023-12-30T03:14:38Z master 8e32c01742) [x86_64-openbsd7.4]
* Backport: 3.0: DONTNEED, 3.1: DONTNEED, 3.2: DONTNEED, 3.3: REQUIRED
----------------------------------------
Between Ruby 3.2 and 3.3, behavior changed so that Regexp#match will allocate a T_MATCH object even when there is no match. Example code:
```ruby
h = {}
GC.start
GC.disable
ObjectSpace.count_objects(h)
matches = h[:T_MATCH] || 0
md = /\A[A-Z]+\Z/.match('1')
ObjectSpace.count_objects(h)
new_matches = h[:T_MATCH] || 0
puts "/\\A[A-Z]+\\Z/.match('1') => #{md.inspect} generates #{new_matches - matches} T_MATCH objects"
```
Result with Ruby 1.9-3.2:
```
/\A[A-Z]+\Z/.match('1') => nil generates 0 T_MATCH objects
```
Results with Ruby 3.3.0 and current master branch:
```
/\A[A-Z]+\Z/.match('1') => nil generates 1 T_MATCH objects
```
This results in a measurable performance decrease for both Sinatra and Roda web applications, as reported at: https://old.reddit.com/r/ruby/comments/18sxtv9/ruby_330_performance_ups_and_downs/
Thanks to GitHub users kiskoza and tagliala for producing a minimal example showing this issue: https://github.com/caxlsx/caxlsx/issues/336
--
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