Are many "createTimer" bad?

[Motte001]

Hi,
I have about 40 createTimer in my rules file. Is this bad, because they waste cpu time and memory even after the timer expired? And will normal variables unset after the rule finished?

Is Thread::sleep(10000) better?

[rlkoshak (Rich Koshak)]

Thread:sleep and Timers are used for two very different purposes. They are not interchangeable.

Thread::sleep(x) vs timers in rules

If you want to do something in the future but don’t want to wait around for it in your rule (e.g. you have more stuff you want to do after kicking off the timer) or you may want to reschedule when the timer triggers or cancel it based on subsequent events a timer is the appropriate thing to use. If you want to wait for a bit and block the rest of the rule from executing until you are done waiting then Thread::sleep is what you want to use. The biggest difference, as @sipvoip describes, is that…

40 Timers does seem like a lot and it makes me wonder if there is a more efficient way to do it but not knowing why you have that many I can’t make a concrete comment.

[Motte001]

Several reasons:

• When Kodi stops playing start a 20 minute timer. If it is still stopped, turn the lights out
• Switch multiple remote sockets at the same time. Switch the first, wait 2 seconds and switch the next, etc…
• When openhab server doesn’t recieve pings from a specific server wait 5 minutes before sending a message

The second could be implemented better, but I don’t know how. I allways need timers in this situation.

[rlkoshak (Rich Koshak)]

Thread::sleep is probably a more appropriate way to implement the middle one. The other two are best implemented with Timers.

I would approach the second by putting all the lights that need to be controlled like that in a Group, create a proxy Switch to control them as a Group, and create a rule which triggers on the proxy Switch:

rule "Serial lights"
when
    Item LightsProxy received command
then
    if(LightsProxy.state == ON){
        gLightsGroup.members.forEach[light| 
            light.sendCommand(ON)
            Thread::sleep(2000)
        ]
    }
    else {
        ...
end