iphone - Anything wrong with leaving timer on and using a flag to control execution on/off? -

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i'm polling router iphone. timer fires every 60 seconds. i'm starting timer in viewdidload , leaving on.

there's flag pollingon set false.

when timer fires, calls mytimerfiredmethod, checks, 

if (self.pollingon) {   self.pollingon = false ;   // run polling code   self.pollingon = true ; }

aside wasting nanosecond or 2 of cpu time, wrong practice?

a timer running although not in use, waste of battery life. it's strange design pattern, running timer without cause.

also if turn on polling, @ worst have wait 60 seconds before update.

i not recommend implementing way. instead, invalidate timer when polling turned off , create new timer when polling turned on.


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