In Files

  • rinda/tuplespace.rb

Parent

Object

Included Modules

  • DRbUndumped
  • MonitorMixin

Rinda::TupleSpace

The Tuplespace manages access to the tuples it contains, ensuring mutual exclusion requirements are met.

The sec option for the write, take, move, read and notify methods may either be a number of seconds or a Renewer object.

Public Class Methods

new(period=60) click to toggle source

Creates a new TupleSpace. period is used to control how often to look for dead tuples after modifications to the TupleSpace.

If no dead tuples are found period seconds after the last modification, the TupleSpace will stop looking for dead tuples.

 
               # File rinda/tuplespace.rb, line 437
def initialize(period=60)
  super()
  @bag = TupleBag.new
  @read_waiter = TupleBag.new
  @take_waiter = TupleBag.new
  @notify_waiter = TupleBag.new
  @period = period
  @keeper = nil
end

Public Instance Methods

move(port, tuple, sec=nil) click to toggle source

Moves tuple to port.

 
               # File rinda/tuplespace.rb, line 484
def move(port, tuple, sec=nil)
  template = WaitTemplateEntry.new(self, tuple, sec)
  yield(template) if block_given?
  synchronize do
    entry = @bag.find(template)
    if entry
      port.push(entry.value) if port
      @bag.delete(entry)
      notify_event('take', entry.value)
      return port ? nil : entry.value
    end
    raise RequestExpiredError if template.expired?

    begin
      @take_waiter.push(template)
      start_keeper if template.expires
      while true
        raise RequestCanceledError if template.canceled?
        raise RequestExpiredError if template.expired?
        entry = @bag.find(template)
        if entry
          port.push(entry.value) if port
          @bag.delete(entry)
          notify_event('take', entry.value)
          return port ? nil : entry.value
        end
        template.wait
      end
    ensure
      @take_waiter.delete(template)
    end
  end
end
notify(event, tuple, sec=nil) click to toggle source

Registers for notifications of event. Returns a NotifyTemplateEntry. See NotifyTemplateEntry for examples of how to listen for notifications.

event can be:

'write'

A tuple was added

'take'

A tuple was taken or moved

'delete'

A tuple was lost after being overwritten or expiring

The TupleSpace will also notify you of the 'close' event when the NotifyTemplateEntry has expired.

 
               # File rinda/tuplespace.rb, line 567
def notify(event, tuple, sec=nil)
  template = NotifyTemplateEntry.new(self, event, tuple, sec)
  synchronize do
    @notify_waiter.push(template)
  end
  template
end
read(tuple, sec=nil) click to toggle source

Reads tuple, but does not remove it.

 
               # File rinda/tuplespace.rb, line 521
def read(tuple, sec=nil)
  template = WaitTemplateEntry.new(self, tuple, sec)
  yield(template) if block_given?
  synchronize do
    entry = @bag.find(template)
    return entry.value if entry
    raise RequestExpiredError if template.expired?

    begin
      @read_waiter.push(template)
      start_keeper if template.expires
      template.wait
      raise RequestCanceledError if template.canceled?
      raise RequestExpiredError if template.expired?
      return template.found
    ensure
      @read_waiter.delete(template)
    end
  end
end
read_all(tuple) click to toggle source

Returns all tuples matching tuple. Does not remove the found tuples.

 
               # File rinda/tuplespace.rb, line 545
def read_all(tuple)
  template = WaitTemplateEntry.new(self, tuple, nil)
  synchronize do
    entry = @bag.find_all(template)
    entry.collect do |e|
      e.value
    end
  end
end
take(tuple, sec=nil, &block) click to toggle source

Removes tuple

 
               # File rinda/tuplespace.rb, line 477
def take(tuple, sec=nil, &block)
  move(nil, tuple, sec, &block)
end
write(tuple, sec=nil) click to toggle source

Adds tuple

 
               # File rinda/tuplespace.rb, line 450
def write(tuple, sec=nil)
  entry = create_entry(tuple, sec)
  synchronize do
    if entry.expired?
      @read_waiter.find_all_template(entry).each do |template|
        template.read(tuple)
      end
      notify_event('write', entry.value)
      notify_event('delete', entry.value)
    else
      @bag.push(entry)
      start_keeper if entry.expires
      @read_waiter.find_all_template(entry).each do |template|
        template.read(tuple)
      end
      @take_waiter.find_all_template(entry).each do |template|
        template.signal
      end
      notify_event('write', entry.value)
    end
  end
  entry
end