Class: Async::Condition

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

Overview

A synchronization primative, which allows fibers to wait until a particular condition is triggered. Signalling the condition directly resumes the waiting fibers and thus blocks the caller.

Direct Known Subclasses

Notification

Defined Under Namespace

Classes: Signal

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Condition

Returns a new instance of Condition.



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# File 'lib/async/condition.rb', line 28

def initialize
	@waiting = []
end

Instance Method Details

#empty? ⇒ Boolean

Is any fiber waiting on this notification?

Returns:

  • (Boolean) 


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# File 'lib/async/condition.rb', line 42

def empty?
	@waiting.empty?
end

#resume(value = nil, task: Task.current) ⇒ void

This method returns an undefined value.

Signal to a given task that it should resume operations.



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# File 'lib/async/condition.rb', line 63

def resume(value = nil, task: Task.current)
	return if @waiting.empty?
	
	task.reactor << Signal.new(@waiting, value)
	
	@waiting = []
	
	return nil
end

#signal(value = nil) ⇒ void

This method returns an undefined value.

Signal to a given task that it should resume operations.

Parameters:

  • value (defaults to: nil) —

    The value to return to the waiting fibers.

See Also:



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# File 'lib/async/condition.rb', line 50

def signal(value = nil)
	waiting = @waiting
	@waiting = []
	
	waiting.each do |fiber|
		fiber.resume(value) if fiber.alive?
	end
	
	return nil
end

#wait ⇒ Object

Queue up the current fiber and wait on yielding the task.

Returns:

  • (Object) 


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# File 'lib/async/condition.rb', line 34

def wait
	@waiting << Fiber.current
	
	Task.yield
end