Object
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.
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 438
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
Moves tuple to port.
# File rinda/tuplespace.rb, line 485
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 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 entry.value
end
template.wait
end
ensure
@take_waiter.delete(template)
end
end
end
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 568
def notify(event, tuple, sec=nil)
template = NotifyTemplateEntry.new(self, event, tuple, sec)
synchronize do
@notify_waiter.push(template)
end
template
end
Reads tuple, but does not remove it.
# File rinda/tuplespace.rb, line 522
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
Returns all tuples matching tuple. Does not remove the found tuples.
# File rinda/tuplespace.rb, line 546
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
Removes tuple
# File rinda/tuplespace.rb, line 478
def take(tuple, sec=nil, &block)
move(nil, tuple, sec, &block)
end
Adds tuple
# File rinda/tuplespace.rb, line 451
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