class Garcon::CopyOnWriteObserverSet
A thread safe observer set implemented using copy-on-write approach: every time an observer is added or removed the whole internal data structure is duplicated and replaced with a new one.
Public Class Methods
# File lib/garcon/task/copy_on_write_observer_set.rb, line 28 def initialize @mutex = Mutex.new @observers = {} end
Public Instance Methods
Adds an observer to this set. If a block is passed, the observer will be created by this method and no other params should be passed
@param [Object] observer
the observer to add
@param [Symbol] func
the function to call on the observer during notification. The default is :update.
@return [Object]
the added observer
# File lib/garcon/task/copy_on_write_observer_set.rb, line 45 def add_observer(observer=nil, func=:update, &block) if observer.nil? && block.nil? raise ArgumentError, 'should pass observer as a first argument or block' elsif observer && block raise ArgumentError.new('cannot provide both an observer and a block') end if block observer = block func = :call end begin @mutex.lock new_observers = @observers.dup new_observers[observer] = func @observers = new_observers observer ensure @mutex.unlock end end
@return [Integer] the observers count
# File lib/garcon/task/copy_on_write_observer_set.rb, line 91 def count_observers observers.count end
@param [Object] observer
the observer to remove
@return [Object]
the deleted observer
# File lib/garcon/task/copy_on_write_observer_set.rb, line 72 def delete_observer(observer) @mutex.lock new_observers = @observers.dup new_observers.delete(observer) @observers = new_observers observer ensure @mutex.unlock end
Deletes all observers @return [CopyOnWriteObserverSet] self
# File lib/garcon/task/copy_on_write_observer_set.rb, line 84 def delete_observers self.observers = {} self end
Notifies all registered observers with optional args and deletes them.
@param [Object] args
Arguments to be passed to each observer
@return [CopyOnWriteObserverSet] self
# File lib/garcon/task/copy_on_write_observer_set.rb, line 112 def notify_and_delete_observers(*args, &block) old = clear_observers_and_return_old notify_to(old, *args, &block) self end
Notifies all registered observers with optional args
@param [Object] args
Arguments to be passed to each observer
@return [CopyOnWriteObserverSet] self
# File lib/garcon/task/copy_on_write_observer_set.rb, line 101 def notify_observers(*args, &block) notify_to(observers, *args, &block) self end