Slock

gem 'slock'

class MySemaphore
  include Slock::Semaphore::Singleton

  SIZE     = 2   # max count of simultaneous locks
  LIFETIME = 600 # max time that lock lives after acquring (in seconds)
  TIMEOUT  = 900 # max time that semaphore waits for lock to acquire before raising an error

  def semaphore_opts
    {
      redis:    Redis.new(url: ENV['REDIS_URL']),
      size:     SIZE,
      lifetime: LIFETIME,
      timeout:  TIMEOUT
    }
  end
end

MySemaphore.acquire { do_something }

sempahore = Slock::Semaphore.new 'uniq_semaphore_key',
  redis: Redis.new(ENV['REDIS_URL']),
  lifetime: 600,
  timeout: 900

semaphore.acquire { do_something }