Application freeze while executing fetch request

Question

In my application, while executing fetch request application get freeze randomly. I have tried with multiple Choice like @synchronized and performblock still hang occur. below is my first fetch request block. Application hang in this fetch request randomly.

+(BXXXX *)getDetailsById:(NSNumber *)Id
    {
        NSFetchRequest *fetch = [[NSFetchRequest alloc] init];
        NSEntityDescription *entityDescription = [NSEntityDescription

                                                  entityForName:@"BXXXX"  inManagedObjectContext:[SDataManager managedObjectContext]];
        [fetch setEntity:entityDescription];
        [fetch setPredicate:[NSPredicate predicateWithFormat:
                             @"(BId = %@)",Id]];


        __block NSArray *bDetails;
        [[SDataManager managedObjectContext] performBlockAndWait:^{
            NSError *error = nil;
            bDetails = [[SDataManager managedObjectContext] executeFetchRequest:fetch error:&error];

        }];

        if([bDetails count] == 1)
            return [bDetails objectAtIndex:0];
        else
            return nil;

    }

//MY Managed object context declaration

+(NSManagedObjectContext *)managedObjectContext
{
    static NSManagedObjectContext *managedObjectContext;
    if(managedObjectContext!=nil){
        return managedObjectContext;
    }
    @try { 
        NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
        if (coordinator != nil) {
            managedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
            [managedObjectContext setPersistentStoreCoordinator: coordinator];
        }
    }
    @catch (NSException *exception) {
        NSLog(@"Exception occur %@",exception);
    }
        return managedObjectContext;

}

Please guide me to fix this issue. I tried hard but i cant fix this issue still now.

Answer 1

I have fixed this issue by creating two managed object context like this.
// Base
    +(NSManagedObjectContext *)managedObjectContext
    {
        static NSManagedObjectContext *managedObjectContext;
        if(managedObjectContext!=nil){
            return managedObjectContext;
        }
        @try { 
            NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
            if (coordinator != nil) {
                managedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
                [managedObjectContext setPersistentStoreCoordinator: coordinator];
            }
        }
        @catch (NSException *exception) {
            NSLog(@"Exception occur %@",exception);
        }
            return managedObjectContext;

    }

//Child

    +(NSManagedObjectContext *)childManagedObjectContext
    {
        static NSManagedObjectContext *managedObjectContext;
        if(managedObjectContext!=nil){
            return managedObjectContext;
        }
        @try {
            NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
            if (coordinator != nil) {
                managedObjectContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
                [managedObjectContext setPersistentStoreCoordinator: coordinator];
            }
        }
        @catch (NSException *exception) {
            NSLog(@"Exception occur %@",exception);
        }
        return managedObjectContext;

    }

for executing the fetch request i have used child managed object context with Concurrency Type as NSPrivateQueueConcurrencyType. It working fine for me. Now UI hang is not there.