| # Copyright 2018 Gentoo Foundation |
| # Distributed under the terms of the GNU General Public License v2 |
| |
| __all__ = ['monotonic'] |
| |
| import time |
| try: |
| import threading |
| except ImportError: |
| import dummy_threading as threading |
| |
| monotonic = getattr(time, 'monotonic', None) |
| |
| if monotonic is None: |
| def monotonic(): |
| """ |
| Emulate time.monotonic() which is available in Python 3.3 and later. |
| |
| @return: A float expressed in seconds since an epoch. |
| """ |
| with monotonic._lock: |
| current = time.time() + monotonic._offset |
| delta = current - monotonic._previous |
| if delta < 0: |
| monotonic._offset -= delta |
| current = monotonic._previous |
| else: |
| monotonic._previous = current |
| return current |
| |
| # offset is used to counteract any backward movements |
| monotonic._offset = 0 |
| monotonic._previous = time.time() |
| monotonic._lock = threading.Lock() |
