Class: Async::Barrier

Inherits:
Object
  • Object
show all
Defined in:
lib/async/barrier.rb

Overview

A barrier is used to synchronize multiple tasks, waiting for them all to complete before continuing.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(parent: nil) ⇒ Barrier

Returns a new instance of Barrier.



28
29
30
31
32
 
# File 'lib/async/barrier.rb', line 28

def initialize(parent: nil)
	@tasks = []
	
	@parent = parent
end

Instance Attribute Details

#tasks ⇒ Object (readonly)

All tasks which have been invoked into the barrier.



35
36
37
 
# File 'lib/async/barrier.rb', line 35

def tasks
  @tasks
end

Instance Method Details

#async(*arguments, parent: (@parent or Task.current), **options, &block) ⇒ Object 



41
42
43
44
45
46
47
 
# File 'lib/async/barrier.rb', line 41

def async(*arguments, parent: (@parent or Task.current), **options, &block)
	task = parent.async(*arguments, **options, &block)
	
	@tasks << task
	
	return task
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


49
50
51
 
# File 'lib/async/barrier.rb', line 49

def empty?
	@tasks.empty?
end

#size ⇒ Object 



37
38
39
 
# File 'lib/async/barrier.rb', line 37

def size
	@tasks.size
end

#stop ⇒ Object 



72
73
74
75
76
 
# File 'lib/async/barrier.rb', line 72

def stop
	# We have to be careful to avoid enumerating tasks while adding/removing to it:
	tasks = @tasks.dup
	tasks.each(&:stop)
end

#wait ⇒ Object

Wait for all tasks.



55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
 
# File 'lib/async/barrier.rb', line 55

def wait
	# TODO: This would be better with linked list.
	while @tasks.any?
		task = @tasks.first
		
		begin
			task.wait
		ensure
			# We don't know for sure that the exception was due to the task completion.
			unless task.running?
				# Remove the task from the waiting list if it's finished:
				@tasks.shift if @tasks.first == task
			end
		end
	end
end