Re: NSURLConnection failing [SOLVED]
-
On Thu, Feb 21, 2008 at 9:23 PM, Doug Penny <doug.penny...> wrote:> I am trying to use NSURLConnection to fetch a few small images (like
> 10k) from various websites. The connections are established and then
> the connection:willSendRequest:redirectResponse: delegate method is
> called and it freezes. It never times out that I know of, at least
> the connection:didFailWithError: delegate is never called. So now for
> the crazy part... sometimes the code works fine and all of the images
> are retrieved. I have tested this with several different sites and it
> seems to be fairly random. I have tried different caching policies as
> well with no change. If it fails, it always seems to fail after the
> redirect is received. I am running this on Leopard with GC enabled.
> Below is the code I am using, I removed all the log messages I was
> using for debugging. If anyone has any ideas they would be greatly
> appreciated.
>
>
> NSURLRequest *request=[NSURLRequest requestWithURL:[NSURL
> URLWithString:imageURL]
>
> cachePolicy:NSURLRequestReloadIgnoringLocalCacheData
>
> timeoutInterval:30.0];
>
> NSURLConnection *imageConnection = [[NSURLConnection alloc]
> initWithRequest:request
>
> delegate:self];
>
> if (!imageConnection) {
> NSLog(@"A problem was encountered while trying to download an
> image from %@", imageURL);
> }
>
>
> ----------------delegate methods-----------------
>
> - (void)connection:(NSURLConnection *)connection
> didReceiveResponse:(NSURLResponse *)response
> {
> [receivedData setLength:0];
> }
>
> - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
> {
> [receivedData appendData:data];
> }
>
> - (NSURLRequest *)connection:(NSURLConnection *)connection
> willSendRequest:(NSURLRequest *)request
> redirectResponse:(NSURLResponse *)redirectResponse
> {
> return request;
> }
>
> - (void)connection:(NSURLConnection *)connection
> didFailWithError:(NSError *)error
> {
> NSLog(@"Error: %@", [error localizedDescription]);
> }
>
> - (void)connectionDidFinishLoading:(NSURLConnection *)connection
> {
> image = [[NSImage alloc] initWithData:receivedData];
> if (!image || ![image isValid]) {
> image = [NSImage imageNamed:@"missingImage.tiff"];
> }
> }
>
>
>
> -Doug
>
Turns out garbage collection was doing me in. When the
NSURLConnection object was hanging out waiting for a response, it
would get collected. To work around this, after creating the
NSURLConnection object I just stick it in a NSMutableSet. When the
delegate gets the -connectionDidFinishLoading: message I remove the
connection object from the set. Works great now.
Doug -
On 2008 Feb, 25, at 8:18, Doug Penny wrote:> Turns out garbage collection was doing me in. When the
> NSURLConnection object was hanging out waiting for a response, it
> would get collected.
I'd call that a pretty serious garbage-collection bug in
NSURLConnection! Unless you'd sent it a -cancel, it ain't garbage. I
sure hope that bugs like this get reported and fixed before I try and
use GC!> To work around this, after creating the
> NSURLConnection object I just stick it in a NSMutableSet. When the
> delegate gets the -connectionDidFinishLoading: message I remove the
> connection object from the set. Works great now.
Yep, that would work-around it. -
On Tue, Feb 26, 2008 at 5:55 PM, Jerry Krinock <jerry...> wrote:> I'd call that a pretty serious garbage-collection bug in
> NSURLConnection! Unless you'd sent it a -cancel, it ain't garbage.
Unless you keep a strong reference to it, it *is* garbage.> On 2008 Feb, 25, at 8:18, Doug Penny wrote:
>> To work around this, after creating the
>> NSURLConnection object I just stick it in a NSMutableSet. When the
>> delegate gets the -connectionDidFinishLoading: message I remove the
>> connection object from the set. Works great now.
>
> Yep, that would work-around it.
It's not a workaround... it looks as if Doug hadn't been using GC,
he'd have been leaking an NSURLConnection.
Hamish -
On Feb 25, 2008, at 18:18, Doug Penny wrote:>> NSURLConnection *imageConnection = [[NSURLConnection alloc]
>> initWithRequest:request
>>
>> delegate:self];
>>
>> if (!imageConnection) {
>> NSLog(@"A problem was encountered while trying to download an
>> image from %@", imageURL);
>> }
>>
[sniped]> Turns out garbage collection was doing me in. When the
> NSURLConnection object was hanging out waiting for a response, it
> would get collected. To work around this, after creating the
> NSURLConnection object I just stick it in a NSMutableSet. When the
> delegate gets the -connectionDidFinishLoading: message I remove the
> connection object from the set. Works great now.
Any object you create on the stack will be gone when the method is
finished :-)
You must keep a reference to the connection.
Best Regards,
Nir Soffer -
On Feb 26, 2008, at 9:14 PM, Nir Soffer wrote:>> Turns out garbage collection was doing me in. When the
>> NSURLConnection object was hanging out waiting for a response, it
>> would get collected. To work around this, after creating the
>> NSURLConnection object I just stick it in a NSMutableSet. When the
>> delegate gets the -connectionDidFinishLoading: message I remove the
>> connection object from the set. Works great now.
>
> Any object you create on the stack will be gone when the method is
> finished :-)
>
> You must keep a reference to the connection.
Or how about turning off garbage collection temporarily for the
object? Something like:
Create the connection and make sure it sticks around:
theConnection = [[NSURLConnection alloc] initWithRequest:request
delegate:self];
[[NSGarbageCollector defaultCollector]
disableCollectorForPointer:theConnection];
Clean up when done:
- (void)connection:(NSURLConnection *)connection didFailWithError:
(NSError *)error
{
[...do your processing...]
[[NSGarbageCollector defaultCollector]
enableCollectorForPointer:connection];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
[...do your processing...]
[[NSGarbageCollector defaultCollector]
enableCollectorForPointer:connection];
}
This seems like less hassle to me, but I don't know if it is good
form. Is it really better keep a strong reference to the connection
object, and if so, why?
António
-----------------------------------------
Perfume is the forgiveness
that the trampled flower casts
upon the heel that crushes it.
-----------------------------------------
