| # Copyright 2013 The Chromium Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| """WatchdogTimer timeout objects.""" |
| |
| import time |
| |
| |
| class WatchdogTimer(object): |
| """A resetable timeout-based watchdog. |
| |
| This object is threadsafe. |
| """ |
| |
| def __init__(self, timeout): |
| """Initializes the watchdog. |
| |
| Args: |
| timeout: The timeout in seconds. If timeout is None it will never timeout. |
| """ |
| self._start_time = time.time() |
| self._timeout = timeout |
| |
| def Reset(self): |
| """Resets the timeout countdown.""" |
| self._start_time = time.time() |
| |
| def GetElapsed(self): |
| """Returns the elapsed time of the watchdog.""" |
| return time.time() - self._start_time |
| |
| def GetRemaining(self): |
| """Returns the remaining time of the watchdog.""" |
| if self._timeout: |
| return self._timeout - self.GetElapsed() |
| else: |
| return None |
| |
| def IsTimedOut(self): |
| """Whether the watchdog has timed out. |
| |
| Returns: |
| True if the watchdog has timed out, False otherwise. |
| """ |
| remaining = self.GetRemaining() |
| return remaining is not None and remaining < 0 |
