swift信号量

        let queue = DispatchQueue(label: "queue")
        queue.async {
            let semaphore = DispatchSemaphore.init(value: 0)
            
            let target = NetworkAPI.syncVehicleCert(password: self.passwordView.value, seid: self.boxNoView.value, step: STEP, typeId: TYPE_ID, vehicleData: jsonData)
            NetworkManager<String>().request(target) { result in
                if result.code == "10000" {
                    semaphore.signal()
                } else {
                    semaphore.signal()
                    SVProgressHUD.showError(withStatus: result.info)
                    return
                }
            }
            semaphore.wait()
            
            let target2 = NetworkAPI.boxBind(password: self.passwordView.value, vin: "")
            NetworkManager<String>().request(target2) { result in
                if result.code == "10000" {
                    semaphore.signal()
                    SVProgressHUD.showSuccess(withStatus: "添加成功")
                    self.navigationController?.popViewController(animated: true)
                } else {
                    SVProgressHUD.showError(withStatus: result.info)
                    return
                }
            }
            semaphore.wait()
        }