Skip to main content

Is an autorelease pool necessary if I"m not creating autoreleased objects?


I mean, if I were absolutely certain I wasn't creating any autoreleased objects, then of course it wouldn't. My real concern is if there's anything else under the hood I don't understand. I have a background thread that calls a function. Must I always create an autorelease pool anyway?




- (void)someFuncOnABackgroundThread
{
//don't seem to need this. no leaks found
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

//do something that doesn't create any objects, or only use alloc/init/release

NSString* str = [[NSString alloc] init];
[str release];
[pool drain];
}


Source: Tips4all
Source: Tips4allSource: CCNA FINAL EXAM

Comments

  1. ultimately, it depends on the interfaces you're using in the implementation.

    example 1

    if you're interacting with Foundation or other objc types, you should. without question.

    to answer specific to the example you've posted: definitely create one in this case -- NSString apis should assume an autorelease pool is in place.

    example 2

    if you're dealing entirely with apis in libc, there is no need.

    bottom line


    it can take a lot of time to understand where it's necessary (or not).
    implementations can change, and they could introduce autoreleased objects.
    you should guarantee a leak is never introduced, especially for such a simple reason.
    it's a simple problem to overcome: if in doubt, create one.

    ReplyDelete
  2. Yep! You have to. You might be calling a function that's internally using autorelease pools, so you never really know if you're using or not any autorelease.

    Good luck!

    ReplyDelete

Post a Comment

Popular posts from this blog

Why is this Javascript much *slower* than its jQuery equivalent?

I have a HTML list of about 500 items and a "filter" box above it. I started by using jQuery to filter the list when I typed a letter (timing code added later): $('#filter').keyup( function() { var jqStart = (new Date).getTime(); var search = $(this).val().toLowerCase(); var $list = $('ul.ablist > li'); $list.each( function() { if ( $(this).text().toLowerCase().indexOf(search) === -1 ) $(this).hide(); else $(this).show(); } ); console.log('Time: ' + ((new Date).getTime() - jqStart)); } ); However, there was a couple of seconds delay after typing each letter (particularly the first letter). So I thought it may be slightly quicker if I used plain Javascript (I read recently that jQuery's each function is particularly slow). Here's my JS equivalent: document.getElementById('filter').addEventListener( 'keyup', function () { var jsStart = (new Date).getTime()...

Is it possible to have IF statement in an Echo statement in PHP

Thanks in advance. I did look at the other questions/answers that were similar and didn't find exactly what I was looking for. I'm trying to do this, am I on the right path? echo " <div id='tabs-".$match."'> <textarea id='".$match."' name='".$match."'>". if ($COLUMN_NAME === $match) { echo $FIELD_WITH_COLUMN_NAME; } else { } ."</textarea> <script type='text/javascript'> CKEDITOR.replace( '".$match."' ); </script> </div>"; I am getting the following error message in the browser: Parse error: syntax error, unexpected T_IF Please let me know if this is the right way to go about nesting an IF statement inside an echo. Thank you.