When is the autorelease pool triggered

Question

i have used autorelease throughout my app and would like to understand the behavior of the autorelease method. When is the default autorelease pool drained? is it based on a

Answer 1

There are (I'd say) 3 main instances when they are created and release:

1.Beginning and very end of your application life-cycle, written in main.m

int main(int argc, char *argv[]) { 
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; 
    int retVal = UIApplicationMain(argc, argv, nil, nil); 
    [pool release]; 
    return retVal; 
}

2.Beginning and very end of each event (Done in the AppKit)

NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; 
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath 
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil 
- (void)loadView 
/* etc etc initialization stuff... */
[pool release];

3.Whenever you want (you can create your own pool and release it. [from apples memory management document])

– (id)findMatchingObject:anObject { 
    id match = nil; 
    while (match == nil) { 
        NSAutoreleasePool *subPool = [[NSAutoreleasePool alloc] init]; 
        /* Do a search that creates a lot of temporary objects. */ 
        match = [self expensiveSearchForObject:anObject]; 
        if (match != nil) { 
            [match retain]; /* Keep match around. */ 
        } 
        [subPool release]; 
    } 
    return [match autorelease];   /* Let match go and return it. */
}