python-snoozebot: A coordinated and interruptible time.sleep() replacement

This module implements a time.sleep() replacement, snoozebot.snooze(), which is more suitable for use in multithreaded apps:

• Threads can be woken up (optionally, with an exception) to facilitate prompt, clean shutdown.
• Snoozing can be cut short if file descriptor(s) becomes readable
• Snoozing threads can specify an interval of acceptable wakeup times, to facilitate grouping jobs together (thus hopefully playing nice with powersavings on modern/mobile CPUs).

Usage:

import snoozebot
from snoozebot import Snoozer, snooze, wake_all

# Interruptable sleep for 1 second
snooze(1.0)

# Sleep for anywhere between 1 minute and 1 hour
snooze(60, 3600)

# Sleep an hour, but wake up early for activity on sys.stdin
reason = snooze(3600, watch_fds=[sys.stdin.fileno()])
if reason[0] == snoozebot.WOKE_FD:
    data = reason[1].read()

# Create a re-usable schedule which can be woken by other means
sn = Snoozer(60, 3600, watch_fds=[sys.stdin.fileno()]))
sn.snooze()

# Other thread wakes us up...
sn.reason(snoozebot.WOKE_CUSTOM, 'Good morning!').wake()

# Just wake all snoozers
wake_all()

# Wake all snoozers with a KeyboardInterrupt!
wake_all(KeyboardInterrupt, 'Time to die')

Dependencies

You will need:

• Python 2.7 or 3.x (author tested on 3.7)

Bugs

This code will fail if firewalls prevent localhost from speaking UDP with itself.

Copyright, license, credits

This code is: (C) Copyright 2020, Bjarni R. Einarsson bre@klaki.net

Snoozebot is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

Snoozebot is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with snoozebot. If not, see https://www.gnu.org/licenses/.