class Syskit::Coordination::Models::DataMonitor

Representation of a single data monitor

Data monitors read some data streams (read: port data readers), feed them into a predicate object that returns a boolean. If the predicate returns true ('triggers'), the monitor will emit a set of events and/or generate a DataMonitoringError Roby exception.

Attributes

data_streams[R]

@return [Syskit::Models::OutputReader] the data streams that

are monitored

emitted_events[R]

@return [Roby::Coordination::Models::Event] the events that

should be emitted when this monitor triggers

@see {emit}

name[R]

@return [String] the monitor name

predicate[R]

@return [#bind] the predicate model. Its new method must

return an object that matches the description of
{Coordination::DataMonitor#predicate}

Public Class Methods

new(name, data_streams) click to toggle source

# File lib/syskit/coordination/models/data_monitor.rb, line 29
def initialize(name, data_streams)
    @name, @data_streams = name, data_streams
    @predicate = nil
    @emitted_events = []
    @raises = false
end

Public Instance Methods

bind(table) click to toggle source

Called to generate an object that can be used by a data monitoring table instance

@return [Syskit::Coordination::DataMonitor]

# File lib/syskit/coordination/models/data_monitor.rb, line 40
def bind(table)
    if !predicate
        raise ArgumentError, "no predicate defined in #{self}"
    end

    data_streams = self.data_streams.map do |reader|
        reader.bind(table.instance_for(reader.port.component_model))
    end
    predicate = self.predicate.bind(table, data_streams)
    monitor = Syskit::Coordination::DataMonitor.new(self, data_streams)
    monitor.trigger_on(predicate)
    emitted_events.each do |ev|
        monitor.emit(table.instance_for(ev))
    end
    monitor.raises = self.raises?
    monitor
end

emit(event) click to toggle source

Call to make this monitor emit the given event when it triggers

@return self

# File lib/syskit/coordination/models/data_monitor.rb, line 62
def emit(event)
    @emitted_events << event
    self
end

raise_exception() click to toggle source

Call to cause this monitor to generate a DataMonitoringError whenever the predicate triggers

@return self

# File lib/syskit/coordination/models/data_monitor.rb, line 71
def raise_exception
    @raises = true
    self
end

to_execution_exception_matcher() click to toggle source

# File lib/syskit/coordination/models/data_monitor.rb, line 104
def to_execution_exception_matcher
    DataMonitoringErrorMatcher.new.from_monitor(self).to_execution_exception_matcher
end

trigger_on(predicate = nil, &predicate_block) click to toggle source

Defines the predicate that will cause this monitor to trigger

@param [#bind] predicate the predicate model object. See

the description of the {predicate} attribute.

If a block is given, it is a shortcut to using the DataMonitorPredicateFromBlock. The block will be called with samples from each of the monitor's data sources, and must return true if the monitor should trigger and false otherwise.

Both cannot be given.

@raise ArgumentError if a predicate is already defined on this

data monitor

@return self

# File lib/syskit/coordination/models/data_monitor.rb, line 92
def trigger_on(predicate = nil, &predicate_block)
    if self.predicate
        raise ArgumentError, "#{self} already has a trigger, you cannot add another one"
    elsif predicate && predicate_block
        raise ArgumentError, "you can give either a predicate object or a predicate block, not both"
    elsif predicate_block
        predicate = DataMonitorPredicateFromBlock.new(data_streams, predicate_block)
    end
    @predicate = predicate
    self
end