29 Jan
2023
29 Jan
'23
8:46 p.m.
Issue #19288 has been updated by duerst (Martin Dürst).
Eregon (Benoit Daloze) wrote in #note-7:
And then of course there is the issue that Ractor is
incompatible with most gems/code out there.
While JSON loading might work, any non-trivial processing after using a gem is unlikely
to work well.
Other Rubies have solved this in a much more efficient, usable and reliable way, by
having no GVL.
But don't other Rubies rely on the programmer to know how to program with threads?
That's only usable if you're used to programming with threads and avoid the
related issues. The idea (where the implementation and many gems may still have to catch
up) behind Ractor is that thread-related issues such as data races can be avoided at the
level of the programming model.
----------------------------------------
Bug #19288: Ractor JSON parsing significantly slower than linear parsing
https://bugs.ruby-lang.org/issues/19288#change-101546
* Author: maciej.mensfeld (Maciej Mensfeld)
* Status: Open
* Priority: Normal
* ruby -v: ruby 3.2.0 (2022-12-25 revision a528908271) [x86_64-linux]
* Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN
----------------------------------------
a simple benchmark:
```ruby
require 'json'
require 'benchmark'
CONCURRENT = 5
RACTORS = true
ELEMENTS = 100_000
data = CONCURRENT.times.map do
ELEMENTS.times.map do
{
rand => rand,
rand => rand,
rand => rand,
rand => rand
}.to_json
end
end
ractors = CONCURRENT.times.map do
Ractor.new do
Ractor.receive.each { JSON.parse(_1) }
end
end
result = Benchmark.measure do
if RACTORS
CONCURRENT.times do |i|
ractors[i].send(data[i], move: false)
end
ractors.each(&:take)
else
# Linear without any threads
data.each do |piece|
piece.each { JSON.parse(_1) }
end
end
end
puts result
```
Gives following results on my 8 core machine:
```shell
# without ractors:
2.731748 0.003993 2.735741 ( 2.736349)
# with ractors
12.580452 5.089802 17.670254 ( 5.209755)
```
I would expect Ractors not to be two times slower on the CPU intense work.
--
https://bugs.ruby-lang.org/