os.time overflow

c_joerg

1250

os.time overflow

« on: 30 / January / 2019, 03:13:12 »

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Can the following script come to an overflow so that the loop hangs forever?

Code: [Select]

z        = 0
shots    = 99999
interval = 3000
t1=os.time()
repeat
  if os.difftime(os.time(),t1)>=0 then
    t1=os.time()+interval
    z=z+1
    shoot()
  end
until z==shots

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reyalp

14110

Re: os.time overflow

« Reply #1 on: 30 / January / 2019, 17:01:00 »

Quote from: c_joerg on 30 / January / 2019, 03:13:12

Can the following script come to an overflow so that the loop hangs forever?

I don't think it should, within reason*. According to the documentation I wrote when I implemented the os lib:

Quote

os.difftime: Just returns (unsigned int)t1 - (unsigned int)t2

So, the result shouldn't be negative unless the *difference* exceeds 2^31 seconds.

* os.time is seconds since 1970 similar to a unix timestamp, so camera time calculations including CHDK Lua will be affected by the Y2038 bug.

« Last Edit: 31 / January / 2019, 17:04:51 by reyalp »

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