Semaphore doesn't raise exception when negative int passed to constructor

Question

Semaphore doesn't raise exception when negative int passed to constructor

flash-gordon opened this issue 3 years ago · 3 comments

The docs say it'll raise an error but it doesn't:

Concurrent::Semaphore.new(-1)

I use cruby.
There's no check for negative number in the code:
https://github.dev/ruby-concurrency/concurrent-ruby/blob/385156117c110808875e1e87d5267147f696f796/lib/concurrent-ruby/concurrent/atomic/mutex_semaphore.rb#L12

Answer 1 · 2022-12-12T12:03:35.000Z

Indeed, could you make a PR to add the check?

Answer 2 · 2022-12-21T11:13:14.000Z

Looking more into this, it seems it's intended to allow a negative initial count since 736ebd1, which also adds a spec for Concurrent::Semaphore.new(-1).
So the docs are wrong and I'll update that.
Semaphore can go negative, that seems a common feature of semaphores.

Answer 3 · 2022-12-21T11:21:34.000Z

Docs are up to date now at https://ruby-concurrency.github.io/concurrent-ruby/master/Concurrent/Semaphore.html#initialize-instance_method