如何减慢iOS进程

Question

I have an app that can send information to a server. This information is stacked up during the day (while the client uses the app), and when he so desires, he can hit the "update" button to send everything on the server.

This always worked fine until he recently had a flow increase and went from updating 10 objects to more than 100.

Obviously, the update takes more time, taht's not the issue.

The issue is, at some point, i'm getting

Error: Error Domain=NSURLErrorDomain Code=-1001 "La requête a expiré." 
UserInfo=0x189874b0 {NSErrorFailingURLStringKey=http://www.*********.be/upload,
NSErrorFailingURLKey=http://www.************.be/upload, 
NSLocalizedDescription=La requête a expiré., 
NSUnderlyingError=0x189abd70 "La requête a expiré."}

For the frenchophobes, " The request has expired " is what i get back, and i've hidden the url with ****, as you noticed.

Now, i've tried locally, it works fine with a small update, but when i loop 150 times on my update (i send 150 times the same thing), at some point i just get the above error X times. This error does not specificall occur with all the last items, it can be 20 in the middle, or 30, etc.

Is there a way i can change that?

Here is a piece of code that must be related to the issue.

// Set the max number of concurrent operations (threads)
    //[operationQueue setMaxConcurrentOperationCount:3]; // Todo: try increasing max thread count
    [operationQueue setMaxConcurrentOperationCount:NSOperationQueueDefaultMaxConcurrentOperationCount]; //dynamic thread count
    self.queueCount = persons.count;
    self.currentQueue = 1;

    for (Person *person in persons) {
        for (int i = 0 ; i<130 ; i++){  //this is where i try to break the app
        [self createSendPersonOperation:person];
        }}

Now what would probably work is put the last line in a "thing" that would slow down the process every 20 or so occurences, so the server or the app doesn't go crazy.

Is this possible? if so, how?

Note : I am a junior dev trying to get into a senior's code, and that guy is not available, so i'm open to all the help i can have.

Edit : also, do you think my error comes from a server-sided issue or is definitly an app-sided issue?

Edit : Complete HTTP request. So for every person that is saved into the app, when the user decides to update, it does that for every Person in the array of persons.

- (void)createSendPersonOperation:(Person *)person
{
    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
    manager.responseSerializer.acceptableContentTypes = [NSSet setWithObjects:@"text/html", @"application/json", nil];

    NSDictionary *params = @{
        @"email": person.email,
        @"gender": person.gender,
        @"language": person.language,
        @"hasFacebook": person.hasFacebook,
        @"sendPostalCard": person.sendPostalCard
    };

    NSLog(@"params: %@", params);

    [manager POST:kURLUpdate parameters:params constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
        // Add picture to the form
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
        NSString *documentsDirectory = [paths objectAtIndex:0];

        NSString *pictureFilePath = [documentsDirectory stringByAppendingPathComponent:person.picture];
        NSURL *pictureURL = [NSURL fileURLWithPath:pictureFilePath];

        [formData appendPartWithFileURL:pictureURL name:@"picture" error:nil];
    } success:^(AFHTTPRequestOperation *operation, id responseObject) {
        NSLog(@"Success: %@", responseObject);

        if ([responseObject isKindOfClass:[NSDictionary class]]) {
            if ([responseObject objectForKey:@"error"]) {
                NSLog(@"Error 1");
                NSDictionary *error = [responseObject objectForKey:@"error"];
                NSLog(@"Error message: %@", [error objectForKey:@"message"]);
            } else {
                // Set Person's sended attribute
                person.sended = @YES;

                [Person saveObject:[[PersistentStack sharedInstance] managedObjectContext] error:nil];
            }
        } else {
            NSLog(@"Error 2");
        }

        [self decreaseQueueCount];
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"Error: %@", error);
        NSLog(@"Parameter that failed : %@", [params objectForKey:@"email"]);
        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Erreur"
                                                            message:[error localizedDescription]
                                                           delegate:nil
                                                  cancelButtonTitle:@"Fermer"
                                                  otherButtonTitles:nil];
        [alertView show];

        self.updateHud.mode = MBProgressHUDModeText;
        self.updateHud.labelText = AMLocalizedString(@"update.failure.message", @"");

        [self.updateHud hide:YES afterDelay:3];
    }];
}

Answer 1

I don't really know the source of your problem, but if you think slowing the app will at least help you understand your problem you could do it with something like this:

NSDate *loopUntil = [NSDate dateWithTimeIntervalSinceNow:15];
while ([loopUntil timeIntervalSinceNow] > 0) {
    [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode
                             beforeDate:loopUntil];
}

It will wait for 15 seconds before continue, so you can put this one after 20~30 requests as you suggested.

I really believe you should consider grouping your requests or something like that so you won't overload your server (if that is really your problem).