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

[flash-gordon]

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

[eregon]

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

[eregon]

Looking more into this, it seems it's intended to allow a negative initial count since https://github.com/ruby-concurrency/concurrent-ruby/commit/736ebd16ff9570534527cf04c1af81ce7e2541bc, 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.

[eregon]

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