class BBS::AI::Semaphore

A counting semaphore: at most a given number of holders at once, the others wait their turn for a while.

Public Class Methods

Source

# File lib/bbs/ai.rb, line 142
def initialize
  @mu    = Mutex.new
  @freed = ConditionVariable.new
  @held  = 0
end

Creates a semaphore nobody holds.

Public Instance Methods

hold (limit:, wait:) { || ... }

Source

# File lib/bbs/ai.rb, line 151
def hold(limit:, wait:)
  raise Busy, 'The model is busy, try again in a moment.' unless take(limit, wait)

  begin
    yield
  ensure
    give
  end
end

Runs the block once fewer than limit hold the semaphore, waiting up to wait seconds for that. Returns the block’s value; raises Busy when the wait runs out.