Source code for eg.Classes.Scheduler

# -*- coding: utf-8 -*-
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import threading
from heapq import heapify, heappop, heappush
from time import time

# Local imports
import eg

[docs]class Scheduler(threading.Thread): """ Sometimes you want to execute some code at a specified time or after a specified time period. EventGhost includes a small scheduler, that helps you to accomplish this. EventGhost creates a single instance of this class that is accessible as :obj:`eg.scheduler`. """ def __init__(self): self.keepRunning = True self.event = threading.Event() self.lock = threading.Lock() self.heap = [(time() + 100000000, None, None, None)] threading.Thread.__init__( self, target=self.MainLoop, name="SchedulerThread" )
[docs] def AddShortTask(self, waitTime, func, *args, **kwargs): """ This function will call the callable `func` after `waitTime` seconds (expressed as a floating point number) with optional parameters, by adding it to the scheduler's queue. A little example:: def MyTestFunc(myArgument): print "MyTestFunc was called with:", repr(myArgument) eg.scheduler.AddShortTask(10.0, MyTestFunc, "just some test data") Ten seconds after invocation of the code it will print the following message to the log:: MyTestFunc was called with: 'just some test data' The function will return an object, that you can use as the `task` identifier for :meth:`CancelTask()`. :Arguments: waitTime The time to wait in floating point seconds. func The callable to invoke after the time has elapsed. \*args Optional positional arguments for the callable. \*\*kwargs Optional keyword arguments for the callable. :Returns: An object to identify the task. """ return self.AddShortTaskAbsolute(time() + waitTime, func, *args, **kwargs)
[docs] def AddShortTaskAbsolute(self, startTime, func, *args, **kwargs): """ This does the same as :meth:`AddShortTask`, but the `startTime` parameter specifies an absolute time expressed in floating point seconds since the epoch. Take a look at the documentation of `Python's time module`_, for more information about this time format. Again a little example:: import time startTime = time.mktime((2007, 8, 15, 16, 53, 0, 0, 0, -1)) eg.scheduler.AddShortTaskAbsolute(startTime, eg.TriggerEvent, "MyEvent") This will trigger the event "Main.MyEvent" at 16:53:00 on 15 August 2007. If you run this code after this point of time, the :func:`eg.TriggerEvent` will be called immediately. .. _Python's time module: """ try: self.lock.acquire() task = (startTime, func, args, kwargs) heappush(self.heap, task) self.event.set() finally: self.lock.release() return task
def AddTask(self, waitTime, func, *args, **kwargs): args = list(args) args.append(func) return self.AddShortTask(waitTime, self.LongTask, *args, **kwargs) def AddTaskAbsolute(self, startTime, func, *args, **kwargs): args = list(args) args.append(func) return self.AddShortTaskAbsolute(startTime, self.LongTask, *args, **kwargs)
[docs] def CancelTask(self, task): """ This will cancel a task formerly added by :meth:`AddShortTask` or :meth:`AddShortTaskAbsolute`, if the task hasn't been started yet. If the task has already been called or simply wasn't added before, the function will raise an IndexError. """ try: self.lock.acquire() self.heap.remove(task) heapify(self.heap) self.event.set() finally: self.lock.release()
def LongTask(self, *args, **kwargs): thrd = threading.Thread( target = args[-1], args = args[:-1], kwargs = kwargs ) thrd.start() def MainLoop(self): timeout = 0 while self.keepRunning: self.event.wait(timeout) self.lock.acquire() self.event.clear() startTime, func, args, kwargs = self.heap[0] if startTime <= time(): heappop(self.heap) self.lock.release() try: func(*args, **kwargs) except: eg.PrintTraceback() startTime = self.heap[0][0] else: self.lock.release() timeout = startTime - time() def Stop(self): def DoIt(): self.keepRunning = False self.AddShortTask(-1, DoIt)