For this background task is AdlibRegister or just Sleep better?

[timmy2]

I'm writing a small prog that will run in the background and sound an alarm if a certain Gmail message arrives in an otherwise unused account.

My inclination is to use a simple While/WEnd loop with a 5 minute Sleep between checking for messages, but I've seen examples here of somewhat similar background tasks that employ AdlibRegister so I'm curious which method is the most reliable and least impactful on the CPU.  Below are two simple scripts that begin to do what I want and represent how I think this could be handled.

While/WEnd with Sleep

#include <CheckMail.au3>
Global $aReturn
Global $iEmails

While 1
    $aReturn = CheckMail("username", "password")
    $iEmails = @extended
    If $iEmails > 0 ExitLoop
    Sleep(300000)   ; check for new messages every 5 minutes
WEnd

;work with contents of $aReturn array that contains the new message(s) found

 

While/WEnd with Sleep and AdlibRegister

#include <CheckMail.au3>
Global $aReturn
Global $iEmails = 0

AdlibRegister('_CallCheckMail',300000) ; check for new messages every 5 minutes

While 1
    Sleep(500000)   ;  I had to put something here. Does higher the value = less CPU demand?
    If $iEmails > 0 ExitLoop
WEnd

;work with contents of $aReturn array that contains the new message(s) found

Func _CallCheckMail
    $aReturn = CheckMail("username", "password")
    $iEmails = @extended
    Return
EndFunc

 

[ViciousXUSMC]

I know putting sleep in a loop is a good practice just to save cpu cycles.  

The main difference in my use/experience is you can keep running a script while Adlibregister does its thing in the background, almost like running a separate script.  While sleep puts everything on hold in the current script.

 

So if your script had other functions that you wanted to keep active and working Adlibregister would allow this, but if your script only has the one purpose, putting everything to sleep should work just as good and be lighter on resources. 

 

The best may be a combination of both.  Your loop with a small sleep (say 100-500ms) to keep the script "alive" with Adlibregister to call your function at the desired intervals. 

[timmy2]

    So if your script had other functions that you wanted to keep active and working Adlibregister would allow this

The best may be a combination of both.  Your loop with a small sleep (say 100-500ms) to keep the script "alive" with Adlibregister to call your function at the desired intervals. 

Thank you for replying. You make an excellent point about when AdlibRegister is most appropriate.

My second example uses a combination of the two but unlike your suggestion of less than a second I had the Sleep period be 8 minutes.  You wrote "to keep the script "alive". Won't AdlibRegister interrupt Sleep  regardless of the Sleep period? Is there any reason to have the Sleep period be real short vs fairly long (500ms vs 8 minutes), especially when AdlibRegister will cause the interrupt in 5 minutes intervals?

[Melba23]

timmy2,

We did some tests a good few years ago (someone had developed a method of pausing for very short periods) and found that you needed to pause the CPU for only about 100 nano-seconds to keep the load down - so the minimum useable value of Sleep(10) (10 milli-seconds) should be more than sufficient in your idle loop whichever method you choose.

M23

Edited July 21, 2015 by Melba23
Got timings wrong

[ViciousXUSMC]

I suppose not, I just figured that if you're going to use a long sleep why use Adlibregister() at all just use sleep.

[BrewManNH]

Sleep(10) is 10 milliseconds, and 100 nanoseconds sleep isn't possible in AutoIt, it can be done without using the AutoIt Sleep function, but you can't use Sleep to go less than 10 milliseconds.

[timmy2]

timmy2,

We did some tests a good few years ago (someone had developed a method of pausing for very short periods) and found that you needed to pause the CPU for only about 100 nano-seconds to keep the load down - so the minimum useable value of Sleep(10) (10 milli-seconds) should be more than sufficient in your idle loop whichever method you choose.

M23

Thank you for replying, Melba23. From your reply I'm not sure what you mean by "you need to pause the CPU".  Let's put my question this way: since my goal is to check for messages every 5 minutes are there any bad side effects from using Sleep (300000), and if so is there a better solution?

[AdmiralAlkex]

Thank you for replying, Melba23. From your reply I'm not sure what you mean by "you need to pause the CPU".  Let's put my question this way: since my goal is to check for messages every 5 minutes are there any bad side effects from using Sleep (300000), and if so is there a better solution?

No that's fine. Go ahead with that Sleep().