On 07/06/2013 01:03, cerr wrote:
Hi,
I have a process that I can trigger only at a certain time. Assume I have a TDM
period of 10min, that means, I can only fire my trigger at the 5th minute of
every 10min cycle i.e. at XX:05, XX:15, XX:25... For hat I came up with
following algorithm which oly leaves the waiting while loop if minute % TDM/2
is 0 but not if minute % TDM is 0:
min = datetime.datetime.now().timetuple().tm_hour*60 +
datetime.datetime.now().timetuple().tm_min
while not (min%tdm_timeslot != 0 ^ min%(int(tdm_timeslot/2)) != 0):
time.sleep(10)
logger.debug("WAIT
"+str(datetime.datetime.now().timetuple().tm_hour*60 +
datetime.datetime.now().timetuple().tm_min))
logger.debug(str(min%(int(tdm_timeslot/2)))+" -
"+str(min%tdm_timeslot))
min = datetime.datetime.now().timetuple().tm_hour*60 +
datetime.datetime.now().timetuple().tm_min
logger.debug("RUN UPDATE CHECK...")
But weird enough, the output I get is something like this:
I would expect my while to exit the loop as soon as the minute turns 1435...
why is it staying in? What am I doing wrong here?
WAIT 1434
3 - 3
WAIT 1434
4 - 4
WAIT 1434
4 - 4
WAIT 1434
4 - 4
WAIT 1434
4 - 4
WAIT 1434
4 - 4
WAIT 1435
4 - 4
WAIT 1435
0 - 5
WAIT 1435
0 - 5
WAIT 1435
0 - 5
WAIT 1435
0 - 5
WAIT 1435
0 - 5
WAIT 1436
0 - 5
RUN UPDATE CHECK...
Possibly it's due to operator precedence. The bitwise operators &, |
and ^ have a higher precedence than comparisons such as !=.
A better condition might be:
min % tdm_timeslot != tdm_timeslot // 2
or, better yet, work out how long before the next trigger time and then
sleep until then.
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