iphone - メインスレッドでメソッドを実行する際の問題

Question

GCD NSOperation を試したメインスレッドでメソッドを実行する際に問題に直面していますが、ここでは何も機能していません。コードを示して、その中の詳細を説明しましょう。

// method which get called first 
- (NSArray*) calendarMonthView:(TKCalendarMonthView*)monthView
                 marksFromDate:(NSDate*)startDate
                        toDate:(NSDate*)lastDate
{
  [self fatchAllEvent];
    // prints null here it generate all event array which i need to use in below method 
  NSLog(@"all event %@",events); 
  [self generateRandomDataForStartDate:startDate endDate:lastDate];
  return self.dataArray;
}

-(void)fatchAllEvent
{
  eventStore = [[EKEventStore alloc] init];
  if([eventStore respondsToSelector:@selector(requestAccessToEntityType:completion:)]){
    __block typeof (self) weakSelf = self; 
    [eventStore requestAccessToEntityType:EKEntityTypeEvent completion:^(BOOL granted, NSError *error){
      if(granted){
        NSLog(@"granted");
        [weakSelf performSelectorOnMainThread:@selector(allCalendarEvent)
         withObject:nil
         waitUntilDone:YES];
                //You can see that i have performed on main thread and wait until done
      }
      else{
        NSLog(@"Not granted");
      }
    }];
  }
  else{
    [self allCalendarEvent];
  }
}

-(void)allCalendarEvent
{
  NSDate *startDate = [NSDate distantPast];
  NSDate *endDate = [NSDate distantFuture];
  NSMutableDictionary *eventsDict = [NSMutableDictionary dictionaryWithCapacity:1024];
  NSDate* currentStart = [NSDate dateWithTimeInterval:0
                                            sinceDate:startDate];
  int seconds_in_year = 60*60*24*365;
  while([currentStart compare:endDate] == NSOrderedAscending){
    NSDate* currentFinish = [NSDate dateWithTimeInterval:seconds_in_year
                                               sinceDate:currentStart];
    if([currentFinish compare:endDate] == NSOrderedDescending){
      currentFinish = [NSDate dateWithTimeInterval:0 sinceDate:endDate];
    }
    NSPredicate *predicate = [eventStore predicateForEventsWithStartDate:currentStart
                                                                 endDate:currentFinish
                                                               calendars:nil];
    [eventStore enumerateEventsMatchingPredicate:predicate
                                      usingBlock:^(EKEvent *event, BOOL *stop) {
                                        if(event){
                                          [eventsDict setObject:event
                                                         forKey:event.eventIdentifier];
                                        }
                                      }];
    currentStart = [NSDate dateWithTimeInterval:(seconds_in_year + 1)
                                      sinceDate:currentStart];
  }
  events = [eventsDict allValues];
  NSLog(@"all event %@",events);   // this gets print after some seconds of the method where i need is already executed 
}

私が望むのは、これがすべて完了する前に先に進むべきではなく、必要な場所でイベント配列を使用できるように先に進むことだけです。