25faa5466b
This makes the value supplied to the `default` option of
`thread_mattr_accessor` to be set in descendant classes
as well as in any new Thread that starts.
Previously, the `default` value provided was set only at the
moment of defining the attribute writer, which would cause
the attribute to be uninitialized in descendants and in other threads.
For instance:
```ruby
class Processor
thread_mattr_accessor :mode, default: :smart
end
class SubProcessor < Processor
end
SubProcessor.mode # => :smart (was `nil` prior to this commit)
Thread.new do
Processor.mode # => :smart (was `nil` prior to this commit)
end.join
```
If a non-`nil` default has been specified, there is a small (~7%)
performance decrease when reading non-`nil` values, and a larger (~45%)
performance decrease when reading `nil` values.
Benchmark script:
```ruby
# frozen_string_literal: true
require "benchmark/ips"
require "active_support"
require "active_support/core_ext/module/attribute_accessors_per_thread"
class MyClass
thread_mattr_accessor :default_value, default: "default"
thread_mattr_accessor :string_value, default: "default"
thread_mattr_accessor :nil_value, default: "default"
end
MyClass.string_value = "string"
MyClass.nil_value = nil
Benchmark.ips do |x|
x.report("default_value") { MyClass.default_value }
x.report("string_value") { MyClass.string_value }
x.report("nil_value") { MyClass.nil_value }
end
```
Before this commit:
```
default_value 2.075M (± 0.7%) i/s - 10.396M in 5.010585s
string_value 2.103M (± 0.7%) i/s - 10.672M in 5.074624s
nil_value 1.777M (± 0.9%) i/s - 8.924M in 5.023058s
```
After this commit:
```
default_value 2.008M (± 0.7%) i/s - 10.187M in 5.072990s
string_value 1.967M (± 0.7%) i/s - 9.891M in 5.028570s
nil_value 1.144M (± 0.5%) i/s - 5.770M in 5.041630s
```
If no default or a `nil` default is specified, there is no performance
impact.
Fixes #43312.
Co-authored-by: Jonathan Hefner <jonathan@hefner.pro>
|
||
|---|---|---|
| .. | ||
| bin | ||
| lib | ||
| test | ||
| .gitignore | ||
| activesupport.gemspec | ||
| CHANGELOG.md | ||
| MIT-LICENSE | ||
| Rakefile | ||
| README.rdoc | ||
= Active Support -- Utility classes and Ruby extensions from Rails
Active Support is a collection of utility classes and standard library
extensions that were found useful for the Rails framework. These additions
reside in this package so they can be loaded as needed in Ruby projects
outside of Rails.
You can read more about the extensions in the {Active Support Core Extensions}[https://edgeguides.rubyonrails.org/active_support_core_extensions.html] guide.
== Download and installation
The latest version of Active Support can be installed with RubyGems:
$ gem install activesupport
Source code can be downloaded as part of the Rails project on GitHub:
* https://github.com/rails/rails/tree/main/activesupport
== License
Active Support is released under the MIT license:
* https://opensource.org/licenses/MIT
== Support
API documentation is at:
* https://api.rubyonrails.org
Bug reports for the Ruby on Rails project can be filed here:
* https://github.com/rails/rails/issues
Feature requests should be discussed on the rails-core mailing list here:
* https://discuss.rubyonrails.org/c/rubyonrails-core