Coverage for melissa/utility/timer.py: 89%

1#!/usr/bin/python3 

2 

3# Copyright (c) 2021-2022, Institut National de Recherche en Informatique et en Automatique (Inria) 

4# All rights reserved. 

5# 

6# Redistribution and use in source and binary forms, with or without 

7# modification, are permitted provided that the following conditions are met: 

8# 

9# * Redistributions of source code must retain the above copyright notice, this 

10# list of conditions and the following disclaimer. 

11# 

12# * Redistributions in binary form must reproduce the above copyright notice, 

13# this list of conditions and the following disclaimer in the documentation 

14# and/or other materials provided with the distribution. 

15# 

16# * Neither the name of the copyright holder nor the names of its 

17# contributors may be used to endorse or promote products derived from 

18# this software without specific prior written permission. 

19# 

20# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 

21# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 

22# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 

23# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE 

24# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 

25# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 

26# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 

27# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 

28# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 

29# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

30 

31import select 

32import socket 

33 

34from melissa.utility import time 

35from melissa.utility.networking import Socket 

36 

37 

38class Timer: 

39 def __init__(self, fd: Socket, interval: time.Time) -> None: 

40 assert interval.total_seconds() > 0 

41 

42 self._fd = fd 

43 self._interval = interval 

44 

45 def run(self) -> None: 

46 while True: 

47 rs, _, _ = select.select( 

48 [self._fd], [], [], self._interval.total_seconds() 

49 ) 

50 

51 if rs == []: 

52 # in case the socket is closed before sending... 

53 # * avoid generation of SIGPIPE 

54 # * handle errno=EPIPE (i.e., BrokenPipeError) 

55 try: 

56 self._fd.send(b'\0', socket.MSG_NOSIGNAL) 

57 except BrokenPipeError: 

58 pass 

59 else: 

60 assert rs[0] == self._fd 

61 return