AFNetworking几乎同时发布了两个请求，响应很混乱

Question

我正在使用AFNetworking 2.0从服务器获取数据。在我的AppDelegate中，我几乎同时发布了两个请求，并且响应1有时返回到request2并且request1超时。
这是我的http客户端类，有什么问题吗？请帮帮我，非常感谢你。

·H

#import <Foundation/Foundation.h>
#import <AFNetworking.h>

@interface HttpClient : AFHTTPRequestOperationManager

+ (instancetype)sharedHTTPClient;
- (instancetype)initWithBaseURL:(NSURL *)url;
- (NSDictionary *)getDataWithDictionary : (NSDictionary *) dic
                                success : (void (^)(NSDictionary* dictionary))success
                                failure : (void (^)(NSError *error))failure
                           networkError : (void (^)(BOOL isNetworkError))networkError;
@end

的.m

@implementation HttpClient

+ (instancetype)sharedHTTPClient{
    static HttpClient *_sharedHTTPClient = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        _sharedHTTPClient = [[self alloc] initWithBaseURL:[NSURL URLWithString:kReachability]];
    });
    return _sharedHTTPClient;
}

- (instancetype)initWithBaseURL:(NSURL *)url{
    self = [super initWithBaseURL:url];
    if (self) {
        self.responseSerializer = [AFHTTPResponseSerializer serializer];
    }
    return self;
}

- (NSDictionary *)getDataWithDictionary : (NSDictionary *) dic
                                success : (void (^)(NSDictionary* dictionary))success
                                failure : (void (^)(NSError *error))failure
                           networkError : (void (^)(BOOL isNetworkError))networkError{

        if ([CheckNetwork isExistenceNetwork]) {
        [self POST:[NSString stringWithFormat:@"%@%@",kReachability,@"/interfaces/"]
        parameters:parameters
           success:^(AFHTTPRequestOperation *operation, id responseObject) {

          }failure:^(AFHTTPRequestOperation *operation, NSError *error) {

          }];

    }else{

    }
    return nil;
}

@end