def __init__(self): super(TaskScheduler,self).__init__() self.task_dao_json = TaskDAOJSON() self.check_event = threading.Event() self.task_queue = queue.PriorityQueue() self.interrupted = False self.load_startup_tasks()
class TaskScheduler(threading.Thread):
def __init__(self):
super(TaskScheduler,self).__init__()
self.task_dao_json = TaskDAOJSON()
self.check_event = threading.Event()
self.task_queue = queue.PriorityQueue()
self.interrupted = False
self.load_startup_tasks()
def init(self, condition_engine):
self.condition_engine = condition_engine
self.running = True
self.start() #only start when properly initialized
def load_startup_tasks(self):
task_list = self.task_dao_json.load_tasks()
for startup_task in task_list:
time = None
if(startup_task['isFixedEvent']):
time = time_utils.to_seconds(startup_task['time'])
else:
time = time_utils.to_future_time(startup_task['time'])
task = (time, startup_task['command'])
self.add_task(task)
def process_next_task(self):
command = self.task_queue.get()[1] #dont care about time anymore, just take the message
logger.info('Executing task: ' + str(command))
self.condition_engine.add_message(('None', command)) # node label is 'None' to indicate that it did not come from a node
def add_task(self, task):
self.task_queue.put(task)
self.check_event.set()
self.interrupted = True
logger.info('Added a task to the task scheduler: ' + str(task))
def stop(self):
self.interrupted = True
self.running = False
self.check_event.set()
def run(self):
while self.running:
self.check_event.clear()
if self.task_queue.empty() == False:
highest_priority_task = self.task_queue.get() #get highest priority item from queue as a tuple (time, command)
sleep_delay = (highest_priority_task[0] - datetime.datetime.now()).total_seconds() #event time - current time = delta time
logger.info('Sleeping task thread for: ' + str(sleep_delay) + ' seconds') #debugging
self.task_queue.put(highest_priority_task) #put the task back
self.check_event.wait(sleep_delay)
self.interrupted = False
else:
self.check_event.wait()
logger.info('Woke up to execute a task')
if self.interrupted == False and self.task_queue.empty() == False: # sleep wasn't interupted by addition of new item
logger.info('Processing the next task')
self.process_next_task() #otherwise, return to recalculating sleep period
self.interrupted = False