NSData dataWithURL

[Andreas Fink]

Hello,

I have a strange behaviour in GNUStep. Before digging deeper, I wanted to know if anyone has a clue.

I have this piece of code:

- (BOOL)updateViaUrl:(NSString *)url /* returns YES on success */

              serial:(NSString *)serial

{

    NSMutableString *full_url = [[NSMutableString alloc]init];

    [full_url appendFormat:@"%@?serial=%@",url,[serial urlencode]];

    NSURL *u = [[NSURL alloc]initWithString:full_url];

    NSError *e= NULL;

    @autoreleasepool

    {

        @try

        {

    #ifdef __APPLE__

            NSData *data = "" style="color: #3900a0" class="">NSData dataWithContentsOfURL:u

                                             options:NSDataReadingUncached

                                               error:&e];

    #else

            NSData *data = "" dataWithContentsOfURL:u];

    #endif

            if((e==0) && (data.length > 0))

            {

                returnValue = YES;

            }

        }

        @catch(NSException *e)

        {

            NSLog(@"Exception while pulling URL %@",full_url);

            returnValue = NO;

        }

    }

    return returnValue;

}

This gets called in a background thread in regular intervalls. Its updating a server with some statistic by pushing some data over https://..

Here's how the process is created:

- (void)runSelectorInBackground:(SEL)aSelector

     withObject:(id)anArgument

{

UMObjectThreadStarter *ts = [[UMObjectThreadStarter alloc]init];

ts.selector = aSelector;

ts.obj      = anArgument;

[NSThread detachNewThreadSelector:@selector(threadStarter:)

toTarget:self

  withObject:ts];

}

(threadStarter: then calls above updateViaURL at some point)

What I have seen is that on gnustep it was producing a crash. This was caused by no autorelease pool being present as it was launched in a background thread.

@autoreleasepool {...}  fixed that crash. (On MacOS X it wasnt crashing).

Now I experience some busyloops in my application _sometimes_ and whenever I load it into the debugger I see that it is in dataWithContentsOfURL: call

To be noted is that the URL called could not be reachable intentionally  (no DNS, firewalls etc) or temporarely (no current coverage, routing issues)

For now I just disabled this code but I wondered if anyone has seen something similar and knows a quick workaround