1 # Copyright 2013 The Chromium Authors. All rights reserved. 2 # Use of this source code is governed by a BSD-style license that can be 3 # found in the LICENSE file. 4 5 """WatchdogTimer timeout objects.""" 6 7 import time 8 9 10 class WatchdogTimer(object): 11 """A resetable timeout-based watchdog. 12 13 This object is threadsafe. 14 """ 15 16 def __init__(self, timeout): 17 """Initializes the watchdog. 18 19 Args: 20 timeout: The timeout in seconds. If timeout is None it will never timeout. 21 """ 22 self._start_time = time.time() 23 self._timeout = timeout 24 25 def Reset(self): 26 """Resets the timeout countdown.""" 27 self._start_time = time.time() 28 29 def GetElapsed(self): 30 """Returns the elapsed time of the watchdog.""" 31 return time.time() - self._start_time 32 33 def GetRemaining(self): 34 """Returns the remaining time of the watchdog.""" 35 if self._timeout: 36 return self._timeout - self.GetElapsed() 37 else: 38 return None 39 40 def GetTimeout(self): 41 """Returns the timout of the watchdog.""" 42 return self._timeout 43 44 def IsTimedOut(self): 45 """Whether the watchdog has timed out. 46 47 Returns: 48 True if the watchdog has timed out, False otherwise. 49 """ 50 remaining = self.GetRemaining() 51 return remaining is not None and remaining < 0 52
