ios 信号量处理网络请求并发

用信号量 处理多个网络请求

#-(void)loadData2{
    [self showHUD:@"加载中"];
    Server *ser=[[Server alloc]init];
    dispatch_group_t group = dispatch_group_create();
    dispatch_group_async(group, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        // 创建信号量
        dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
        [ser QueryBindCardWithCrashFlag:@"" Success:^(id obj) {
//            [self.myTableView headerEndRefreshing];
                ServerResponse *response = (ServerResponse *)obj;
                if(response.state == 0)
                {
                    cardModel = response.data;
                    if ([cardModel.isOpenMember intValue] ==1)
                    {//已开通
                        // 如果请求成功，发送信号量
                        dispatch_semaphore_signal(semaphore);
                    }else{
                        [self showHudTipStr:@"暂未开通运友宝"];
                        dispatch_semaphore_signal(semaphore);
                    }
                }
                else
                {
                    dispatch_semaphore_signal(semaphore);
                }
            
        } failture:^{
            [self hideHUD];
            dispatch_semaphore_signal(semaphore);
        }];

        // 在网络请求任务成功之前，信号量等待中
        dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
    });
    dispatch_group_async(group, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        // 创建信号量
        dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
        [ser QueryMoneyWithcustAcctId:cardModel.custAcctId Reserve:@"" Success:^(id obj) {
            ServerResponse *response = (ServerResponse *)obj;
            [self hideHUD];
            NSLog(@"%d",response.state);
            if (response.state == 0)
            {
                //查询余额
                moneyModel = response.data;
                if (moneyModel.totalBalance==nil) {
                    moneyModel.totalBalance=@"0";
                }
                if (moneyModel.totalTranOutAmount==nil) {
                    moneyModel.totalTranOutAmount=@"0";
                }
                dispatch_semaphore_signal(semaphore);

            }
            else
            {
                [self showHudTipStr:response.message];
                dispatch_semaphore_signal(semaphore);

            }
        } failture:^{
            [self showHudTipStr:@"连接服务器失败"];
        }];
        
        // 在网络请求任务成功之前，信号量等待中
        dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);

    });
    dispatch_group_notify(group, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        dispatch_async(dispatch_get_main_queue(), ^{
            [self hideHUD];
            [self.myTableView headerEndRefreshing];
            [self.myTableView reloadData];
        });
    });

}