Class: Async::WorkerPool::Promise

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

Overview

Execute the given work in a background thread.

Instance Method Summary collapse

Constructor Details

#initialize(work) ⇒ Promise

Create a new promise.



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# File 'lib/async/worker_pool.rb', line 32

def initialize(work)
	@work = work
	@state = :pending
	@value = nil
	@guard = ::Mutex.new
	@condition = ::ConditionVariable.new
	@thread = nil
end

Instance Method Details

#call ⇒ Object

Execute the work and resolve the promise.



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

def call
	work = nil
	
	@guard.synchronize do
		@thread = ::Thread.current
		
		return unless work = @work
	end
	
	resolve(work.call)
rescue Exception => error
	reject(error)
end

#cancel ⇒ Object

Cancel the work and raise an exception in the background thread.



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# File 'lib/async/worker_pool.rb', line 77

def cancel
	return unless @work
	
	@guard.synchronize do
		@work = nil
		@state = :cancelled
		@thread&.raise(Interrupt)
	end
end

#wait ⇒ Object

Wait for the work to be done.



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# File 'lib/async/worker_pool.rb', line 90

def wait
	@guard.synchronize do
		while @state == :pending
			@condition.wait(@guard)
		end
		
		if @state == :failed
			raise @value
		else
			return @value
		end
	end
end