Class: Concurrent::CopyOnWriteObserverSet

Inherits:
Object
  • Object
show all
Defined in:
lib/concurrent/atomic/copy_on_write_observer_set.rb

Overview

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.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ CopyOnWriteObserverSet 



8
9
10
11
 
# File 'lib/concurrent/atomic/copy_on_write_observer_set.rb', line 8

def initialize
  @mutex = Mutex.new
  @observers = {}
end

Instance Method Details

#add_observer(observer = nil, func = :update, &block) ⇒ Object

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



18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
 
# File 'lib/concurrent/atomic/copy_on_write_observer_set.rb', line 18

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

#count_observers ⇒ Integer 



62
63
64
 
# File 'lib/concurrent/atomic/copy_on_write_observer_set.rb', line 62

def count_observers
  observers.count
end

#delete_observer(observer) ⇒ Object 



43
44
45
46
47
48
49
50
51
 
# File 'lib/concurrent/atomic/copy_on_write_observer_set.rb', line 43

def delete_observer(observer)
  @mutex.lock
  new_observers = @observers.dup
  new_observers.delete(observer)
  @observers = new_observers
  observer
ensure
  @mutex.unlock
end

#delete_observers ⇒ CopyOnWriteObserverSet

Deletes all observers



55
56
57
58
 
# File 'lib/concurrent/atomic/copy_on_write_observer_set.rb', line 55

def delete_observers
  self.observers = {}
  self
end

#notify_and_delete_observers(*args, &block) ⇒ CopyOnWriteObserverSet

Notifies all registered observers with optional args and deletes them.



78
79
80
81
82
 
# File 'lib/concurrent/atomic/copy_on_write_observer_set.rb', line 78

def notify_and_delete_observers(*args, &block)
  old = clear_observers_and_return_old
  notify_to(old, *args, &block)
  self
end

#notify_observers(*args, &block) ⇒ CopyOnWriteObserverSet

Notifies all registered observers with optional args



69
70
71
72
 
# File 'lib/concurrent/atomic/copy_on_write_observer_set.rb', line 69

def notify_observers(*args, &block)
  notify_to(observers, *args, &block)
  self
end