class Orocos::Async::CORBA::AttributeBase

# File lib/orocos/async/attributes.rb, line 11
def initialize(async_task,attribute,options=Hash.new)
    super(attribute.name,async_task.event_loop)
    @options = Kernel.validate_options options, :period => default_period
    @task = async_task
    @mutex = Mutex.new

    disable_emitting do
        reachable!(attribute)
    end
    @poll_timer = @event_loop.async_every(method(:raw_read), {:period => period, :start => false,
                                          :known_errors => Orocos::Async::KNOWN_ERRORS}) do |data,error|
        if error
            @poll_timer.cancel
            self.period = @poll_timer.period
            @event_loop.once do
                event :error,error
            end
        else
            if data
                if @raw_last_sample != data
                    @raw_last_sample = data
                    event :raw_change,data
                    event :change,Typelib.to_ruby(data)
                end
            end
        end
    end
    @poll_timer.doc = attribute.full_name
    @task.on_unreachable do
        unreachable!
    end
rescue Orocos::NotFound => e
    emit_error e
end

# File lib/orocos/async/attributes.rb, line 46
def last_sample
    if @raw_last_sample
        Typelib.to_ruby(@raw_last_sample)
    end
end

# File lib/orocos/async/attributes.rb, line 133
def on_change(policy = Hash.new,&block)
    @policy = if policy.empty?
                   options
               elsif !@policy
                   policy
               elsif @policy == policy
                   @policy
               else
                   Orocos.warn "Property #{full_name} cannot emit :change with different policies."
                   Orocos.warn "The current policy is: #{@policy}."
                   Orocos.warn "Ignoring policy: #{policy}."
                   @policy
               end
    on_event :change,&block
end

# File lib/orocos/async/attributes.rb, line 117
def on_raw_change(policy = Hash.new,&block)
    @policy = if policy.empty?
                   options
               elsif !@policy
                   policy
               elsif @policy == policy
                   @policy
               else
                   Orocos.warn "Property #{full_name} cannot emit :raw_change with different policies."
                   Orocos.warn "The current policy is: #{@policy}."
                   Orocos.warn "Ignoring policy: #{policy}."
                   @policy
               end
    on_event :raw_change,&block
end

# File lib/orocos/async/attributes.rb, line 67
def period=(period)
    super
    @poll_timer.period = self.period
end

# File lib/orocos/async/attributes.rb, line 58
def reachable!(attribute,options = Hash.new)
    super
    @raw_last_sample = nil
end

# File lib/orocos/async/attributes.rb, line 63
def reachable?
    super && @raw_last_sample
end

# File lib/orocos/async/attributes.rb, line 92
def really_add_listener(listener)
    super
    if listener.event == :raw_change
        if !@poll_timer.running?
            @poll_timer.start(period)
        end
        listener.call(@raw_last_sample) if @raw_last_sample && listener.use_last_value?
    elsif listener.event == :change
        if !@poll_timer.running?
            @poll_timer.start(period)
        end
        listener.call(Typelib.to_ruby(@raw_last_sample)) if @raw_last_sample && listener.use_last_value?
    end
end

# File lib/orocos/async/attributes.rb, line 107
def remove_listener(listener)
    super
    if number_of_listeners(:change) == 0
        if @poll_timer.running?
            @poll_timer.stop
        end
        @policy = nil
    end
end

# File lib/orocos/async/attributes.rb, line 52
def unreachable!(options = Hash.new)
    super
    @raw_last_sample = nil
    @poll_timer.cancel
end

# File lib/orocos/async/attributes.rb, line 74
def wait(timeout = 5.0)
    # make sure the poll timer is running otherwise wait
    # will always fail
    poll_timer_running  = @poll_timer.running?
    @poll_timer.start(0.01) unless poll_timer_running
    time = Time.now
    @event_loop.wait_for do
        if timeout && timeout <= Time.now-time
            Utilrb::EventLoop.cleanup_backtrace do
                raise Orocos::NotFound,"#{self.class}: #{respond_to?(:full_name) ? full_name : name} is not reachable after #{timeout} seconds"
            end
        end
        reachable?
    end
    @poll_timer.stop unless poll_timer_running
    self
end