Core Data freezing main thread - ios

Question

I am kinda new to Core Data, and have encountered some wierd stuff when making a point counter for a game.
I have this code for creating a new Point-object for a match (the static holder "button.pointHolder" is not a core data-object):
NSLog(#"before block");
[self.match.managedObjectContext performBlock:^{
NSLog(#"in block");
PointHolderType *holderType = [self.matchController insertPointHolderForTeam:self.match.homeTeam withStaticHolder:button.pointHolder];
dispatch_async(dispatch_get_main_queue(), ^{
NSLog(#"in block dispatch_get_main_queue");
//Updating UI
});
}];
NSLog(#"after block");
This seems to block the main thread when my core data is growing. (It doesn't matter if its a new match instance without point holders or not. It is lagging when my core data is growing no matter what)
The logs:
2013-11-04 11:48:53.059 [463:60b] before block
2013-11-04 11:48:53.060 [463:60b] after block
2013-11-04 11:48:53.062 [463:60b] in block
2013-11-04 11:48:53.606 [463:60b] in block dispatch_get_main_queue
And I'm creating my object like this:
- (PointHolderType *)insertPointHolderForTeam:(NSString*)team withStaticHolder:(PointHolder *)holder
{
PointHolderType *holderType = [NSEntityDescription insertNewObjectForEntityForName:#"PointHolderType" inManagedObjectContext:self.match.managedObjectContext];
holderType.type = [NSNumber numberWithInt:holder.pointCounterType];
holderType.team = team;
holderType.points = [NSNumber numberWithInteger:holder.pointsAdded];
holderType.match = self.match;
return holderType;
}
Also, if i remove this line:
holderType.match = self.match;
I get a fully responsive UI. This makes me wonder if it has something to do with my managedObjectContext which I'm using from the "match" itself.
Other info:
I'm creating my match like this:
Match *newMatch = [NSEntityDescription insertNewObjectForEntityForName:#"Match" inManagedObjectContext:self.managedObjectContext];
And my managedObjectContext like this:
-(void) useDocument
{
NSURL *url = [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
url = [url URLByAppendingPathComponent:#"brannboll_document"];
UIManagedDocument *document = [[UIManagedDocument alloc] initWithFileURL:url];
if(![[NSFileManager defaultManager] fileExistsAtPath:url.path])
{
//create
[document saveToURL:url forSaveOperation:UIDocumentSaveForCreating completionHandler:^(BOOL success) {
if(success)
{
self.managedObjectContext = document.managedObjectContext;
}
}];
}
else if(document.documentState == UIDocumentStateClosed)
{
//Open it
[document openWithCompletionHandler:^(BOOL success) {
self.managedObjectContext = document.managedObjectContext;
}];
}
else //try to use it
{
self.managedObjectContext = document.managedObjectContext;
}
}
Any ideas? What am I missing?
EDIT:
Thanks to CouchDeveloper in the comments, I managed to find the root of the problems; My parent Core Data Table View controller, whose fetchrequest got constantly called when adding relations to a Match-object. Why? You tell me. I solved it by nil-ing the actual fetchrequest in viewdiddisappear, and vice verca.
Thanks!