Lua question: Best way to schedule stuff?

[jackstone]

This question is aimed at C4 driver developers. I know there is not really mutual help between us but I'm throwing the question anyway...

I'm looking for a simple way to schedule stuff within a Lua script, without using C4 scheduling agent and without using the C4 API that only add scheduled event but can't add task to run..

I know there is a way, some of you guys have done it, maybe someone will have the kindness to share how he have done it... Or maybe C4 staff on this forum can help on that?

TIA

 

[alanchow]

17 hours ago, jackstone said:

This question is aimed at C4 driver developers. I know there is not really mutual help between us but I'm throwing the question anyway...

I'm looking for a simple way to schedule stuff within a Lua script, without using C4 scheduling agent and without using the C4 API that only add scheduled event but can't add task to run..

I know there is a way, some of you guys have done it, maybe someone will have the kindness to share how he have done it... Or maybe C4 staff on this forum can help on that?

TIA

 

Method 1 - Utilise os.time() and a initial timer set up a reoccurring timer to the period you want (this lines it up to the exact second.  You will need to do a bit of math eg every minute/five/half hour/hour) and utilise a table of a schedules (time stamps) to determine when you want to fire a schedule)

Method 2 - similar to above but rather than using timestamps utilise os.date to figure out the day of the week, month, year if you want to do reoccurring based on any of those factors.

Hope that helps.

[jackstone]

Thanks Alan, the method I've figured out is to do a recurring timer that read os.time in epoch format, than do some math to see if the current time match a schedule each time the looping timer expire. With some tolerance since the time input comes from an interval and not real time.

I'm not really sure if that is close to what you've explained?

[alanchow]

17 hours ago, jackstone said:

Thanks Alan, the method I've figured out is to do a recurring timer that read os.time in epoch format, than do some math to see if the current time match a schedule each time the looping timer expire. With some tolerance since the time input comes from an interval and not real time.

I'm not really sure if that is close to what you've explained?

Yep similar concept.  My method just aligns it to the minute rather than randomly whenever the timer starts.

[RyanE]

Just be aware that you should of course do your time / date polling as infrequently as possible.

In other words, don't be stupid and set a 1 second (or worse, sub-second) timer to check os.time or os.date repeatedly...

RyanE
 

[jackstone]

3 hours ago, alanchow said:

Yep similar concept.  My method just aligns it to the minute rather than randomly whenever the timer starts.

I see... so you're pulling os.time only once and then trust your recurring timer to keep track of time?
 

 

[Neo1738]

4 hours ago, jackstone said:

I see... so you're pulling os.time only once and then trust your recurring timer to keep track of time?
 

 

I think he means don't bog down the cpu by constantly polling for times set it every hr or so to verify time.

[jackstone]

5 minutes ago, Neo1738 said:

I think he means don't bog down the cpu by constantly polling for times set it every hr or so to verify time.

Yeah I understand that part.

[jackstone]

I think I got it, at least for my case. I only have 8 daily tasks to schedule within the driver, so instead of polling os.time periodically, I just have to get the current time once a day, then start 8 timers each 24h interval, each timer will be set to the number of seconds before triggering based on the actual epoch time. 8 timers should be more efficient than a recurring one plus a loop of IF-THEN to check if an event is set to trigger...

[alanchow]

6 minutes ago, jackstone said:

I think I got it, at least for my case. I only have 8 daily tasks to schedule within the driver, so instead of polling os.time periodically, I just have to get the current time once a day, then start 8 timers each 24h interval, each timer will be set to the number of seconds before triggering based on the actual epoch time. 8 timers should be more efficient than a recurring one plus a loop of IF-THEN to check if an event is set to trigger...

If it’s 8 timers only you should do the math to align the timer up to whenever you have set it once off first off.  After that 24 hour repeating timers will do.