class RR(Scheduler):
"""Round Robin scheduler"""
def init(self):
self.ready_list = []
self.delay = 2
self.timer = Timer(self.sim,
RR.end_event, (self, self.processors[0]),
self.delay,
cpu=self.processors[0],
in_ms=True)
self.interupt = False
def on_activate(self, job):
self.ready_list.append(job)
job.cpu.resched()
def on_terminated(self, job):
if job in self.ready_list:
self.ready_list.remove(job)
self.timer.stop()
job.cpu.resched()
def end_event(self, cpu):
self.interupt = True
self.timer.stop()
cpu.resched()
def schedule(self, cpu):
if self.ready_list:
job = self.ready_list[0]
if not cpu.running or self.interupt:
self.interupt = False
self.timer.start()
self.ready_list.remove(job)
if cpu.running:
self.ready_list.append(cpu.running)
return (job, cpu)
else:
return None
