Class: Actuator::Mutex

Inherits:
Object
  • Object
show all
Defined in:
lib/actuator/mutex.rb

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Mutex

Returns a new instance of Mutex.



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# File 'lib/actuator/mutex.rb', line 3

def initialize
  @waiters = []
end

Instance Method Details

#_wake_up(job) ⇒ Object 



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# File 'lib/actuator/mutex.rb', line 21

def _wake_up(job)
  if job.sleep_timer
    job.wake!
  elsif job.mutex_asleep
    job.mutex_asleep = nil
    job.fiber.resume
  else
    raise FiberError, "_wake_up called for job #{job.id} which is #{job.state}"
  end
end

#lock ⇒ Object

Raises:

  • (FiberError) 


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# File 'lib/actuator/mutex.rb', line 7

def lock
  job = Job.current
  raise FiberError if @waiters.include? job
  @waiters << job
  if @waiters.size > 1
    Job.yield
  end
  true
end

#locked? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/actuator/mutex.rb', line 17

def locked?
  !@waiters.empty?
end

#sleep(timeout = nil) ⇒ Object 



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# File 'lib/actuator/mutex.rb', line 32

def sleep(timeout=nil)
  unlock
  if timeout
    Job.sleep(timeout)
  else
    job = Job.current
    job.mutex_asleep = self
    begin
      Job.yield
    ensure
      job.mutex_asleep = nil
    end
  end
  nil
ensure
  lock
end

#synchronize ⇒ Object 



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# File 'lib/actuator/mutex.rb', line 68

def synchronize
  lock
  yield
ensure
  unlock
end

#try_lock ⇒ Object 



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# File 'lib/actuator/mutex.rb', line 50

def try_lock
  lock unless locked?
end

#unlock ⇒ Object 



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# File 'lib/actuator/mutex.rb', line 54

def unlock
  unless @waiters.first == Job.current
    raise "[Job #{Job.current.id}] Mutex#unlock called from job which does not have the lock - @waiters: #{@waiters.map(&:id).inspect}"
  end
  @waiters.shift
  unless @waiters.empty?
    Actuator.next_tick do
      next if @waiters.empty?
      @waiters.first.fiber.resume
    end
  end
  self
end