concurrency.groovy

class ConcurrencyTest {

  public static void main(String[] args) {
		def consumer = new SlowConsumer().start();
		def producer = new FastProducer(consumer).start();
		
		100.times {
			producer << it
		}
		[consumer,producer]*.stop()
		[consumer,producer]*.join()
	}
	
}



class FastProducer extends DefaultActor {
	
	def target
	
	def FastProducer(SlowConsumer consumer){
		this.target = consumer
	}
	
	def log = LoggerFactory.getLogger(FastProducer.class)
	
	void act() {
		loop() {
			react { message ->
				target << message
			}
		}		
	}
}

class SlowConsumer extends DefaultActor {
	def log = LoggerFactory.getLogger(SlowConsumer.class)
	void act() {
		loop(){
			react { 
				log.info "received message : ${it}"
				Thread.sleep(10)
			}
			
		}
	}
	
}

//Same thread is used for all SlowConsumers
//output of this:
/*
14:33:05,685  INFO Actor Thread 2 com.emusic.catalog.SlowConsumer:? - received message : 0
14:33:05,704  INFO Actor Thread 2 com.emusic.catalog.SlowConsumer:? - received message : 1
14:33:05,715  INFO Actor Thread 2 com.emusic.catalog.SlowConsumer:? - received message : 2
14:33:05,726  INFO Actor Thread 2 com.emusic.catalog.SlowConsumer:? - received message : 3
14:33:05,737  INFO Actor Thread 2 com.emusic.catalog.SlowConsumer:? - received message : 4
14:33:05,749  INFO Actor Thread 2 com.emusic.catalog.SlowConsumer:? - received message : 5
14:33:05,760  INFO Actor Thread 2 com.emusic.catalog.SlowConsumer:? - received message : 6
14:33:05,771  INFO Actor Thread 2 com.emusic.catalog.SlowConsumer:? - received message : 7
14:33:05,782  INFO Actor Thread 2 com.emusic.catalog.SlowConsumer:? - received message : 8
14:33:05,794  INFO Actor Thread 2 com.emusic.catalog.SlowConsumer:? - received message : 9
14:33:05,805  INFO Actor Thread 2 com.emusic.catalog.SlowConsumer:? - received message : 10
*/