[AC-2729] iOS: setInterval loses 1 sec every 30 sec on certain devices

GitHub Issue	n/a
Type	Bug
Priority	n/a
Status	Closed
Resolution	Invalid
Resolution Date	2011-12-05T04:15:18.000+0000
Affected Version/s	n/a
Fix Version/s	n/a
Components	Titanium SDK & CLI
Labels	n/a
Reporter	Sumit Kataria
Assignee	Paul Dowsett
Created	2011-12-01T21:42:48.000+0000
Updated	2016-03-08T07:47:37.000+0000

Description

setInterval function is not working correctly. It is losing time. In common language, if a watch counts 30 sec it is counting 29 sec. Attached project will demonstrate same. You can not replicate this in iOS simulator - this will happen only in devices. The timer function is extremely important for my project.

Attachments

File	Date	Size
timer.zip	2011-12-01T21:42:48.000+0000	536702

Comments

Paul Dowsett 2011-12-02

Sumit Thank you for raising this issue. Your code contains a lot of unnecessary code that could be influencing the behavior. Would you please write a test case, as described in [Creating a Test Case](http://wiki.appcelerator.org/display/guides/How+to+Submit+a+Bug+Report#HowtoSubmitaBugReport-CreatingaTestCase)? Also, test cases should be added to the body of the ticket rather than as an attachment, to make it easy for the engineering team to assess. Once this is done, I will be able to move it across to the main project so that the engineering team can work on it. Thanks

Paul Dowsett 2011-12-05

As kindly, and correctly, explained by JongEun, Javascript timers are not guaranteed.

   > That's not a bug.
   > Javascript timer delay is not guranteed.
   > Becase Javascript excutes on a single thread.
   > Check this blog article
   > http://ejohn.org/blog/how-javascript-timers-work/
   >
   > You should not count in interval function :
   >
   > self.total_sec--;
   >
   >
   > how about this way?
   >
   > 1. when the timer start, save current Time
   >
   > 2.  just caculate time and update view on interval timer function
   >
   > var startTime = new Date();
   >
   > setInterval(function(){
   >
   >
   >   var timegap = new Date() - startTime;
   >
   >   // do somthing (such as update view ....)
   >
   >
   > },1000);
   >
   >
   > CodeStrong!
   >
   >
   > JongEun.

This solution should resolve this for you. Hence, marking this ticket as invalid.

Sumit Kataria 2011-12-05

Thanks Paul for referring this. Yes above comment solved my blocker, but main issue is this is happening in a particular set of devices and others are behaving normally.
Sumit Kataria 2011-12-05

Closing ticket

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