用NSURLConnection随机崩溃

Question

我遇到了随机崩溃，我没有任何信息。崩溃Xcode告诉我这个：

或者：

所有离开应用程序的连接都是从NSObject类运行的，代码是：

·H

@protocol LoadMysqlDelegate <NSObject>
@required
-(void)loadMysql:(NSArray *)array;
@end

@interface LoadMysql : NSObject <NSURLConnectionDataDelegate, NSURLConnectionDelegate>

@property (nonatomic, strong) id <LoadMysqlDelegate> delegate;

-(void)connectionMysqlWithNick:(NSString *)nick;

@end

的.m

#import "LoadMysql.h"

@implementation LoadMysql {

    NSMutableArray *_arrayP;
    NSMutableData *_data;    
}

-(void)connectionMysqlWithNick:(NSString *)nick {

    _data = [[NSMutableData alloc] init];
    _arrayP = [[NSMutableArray alloc] init];

    [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES];

    NSString *stringUrl = [NSString stringWithFormat:@"http://www.bla.it/load.php?valNick=%@",nick];

    NSURL *url = [NSURL URLWithString:stringUrl];
    NSURLRequest *request = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringLocalAndRemoteCacheData timeoutInterval:50.0f];
    NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:NO];

    [connection scheduleInRunLoop:[NSRunLoop mainRunLoop] forMode:NSDefaultRunLoopMode];
    [connection start];
}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)aResponse
{
    [_data setLength:0];

}

-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {

    [_data appendData:data];
}


-(void)connectionDidFinishLoading:(NSURLConnection *)connection {


    id jsonObjects = [NSJSONSerialization JSONObjectWithData:_data options:NSJSONReadingMutableContainers error:nil];

    for (NSDictionary *dataDict in jsonObjects) {

        NSString *stringI = [dataDict objectForKey:@"name"];
        NSString *stringT = [dataDict objectForKey:@"type"];

        NSDictionary *_dict = [NSDictionary dictionaryWithObjectsAndKeys:stringI,@"name",stringT,@"type", nil];

        [_arrayP addObject:_dict];

    }

    [_delegate loadMysql:_arrayP];

    [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];

}

@end

问题可能源于同时启动更多连接的事实？

大多数连接都脱离后台线程

修改

我已经改变了：

@property (nonatomic, strong) id <LoadMysqlDelegate> delegate;

使用：

@property (nonatomic, weak) id <LoadMysqlDelegate> delegate;

但问题仍然存在。

编辑2

我终于有了完整的堆栈跟踪：