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近期小细节总结

news 2026/5/12 12:08:14

串口并发调用

单个串口通讯（Modbus RTU也算），业务流程中的串口调用，既有定时轮询又有依次发送，也就是涉及到并发调用通讯的，不要犹豫，为通讯管理模块建立消息队列

不用纠结锁的问题，天然线程安全
定时任务和手动操作随便调用，自动排队

// 请求队列
private readonly Channel<ModbusRequest> _requestChannel = Channel.CreateBounded<ModbusRequest>(20);
private readonly CancellationTokenSource _processingCts = new CancellationTokenSource();
private Task _processingTask;// 添加请求类private class ModbusRequest{public byte DeviceAddress { get; set; }public byte FunctionCode { get; set; }public ushort RegisterAddress { get; set; }public ushort Value { get; set; }public ushort RegisterCount { get; set; }public TaskCompletionSource<byte[]> CompletionSource { get; set; }}// 启动请求处理任务_processingTask = Task.Run(ProcessModbusRequests);/// <summary>/// Modbus命令内部实现（无锁版本）/// </summary>private async Task<byte[]> SendModbusCommandInternal(byte deviceAddress, byte functionCode, ushort registerAddress, ushort value = 0, ushort registerCount = 1){try{// 构建请求帧（原SendModbusCommand的逻辑移到这里）byte[] request;if (functionCode == 0x03) // 读取保持寄存器
                {request = new byte[6];request[0] = deviceAddress;request[1] = functionCode;request[2] = (byte)(registerAddress >> 8);request[3] = (byte)(registerAddress & 0xFF);request[4] = (byte)(registerCount >> 8);request[5] = (byte)(registerCount & 0xFF);}else if (functionCode == 0x06) // 写单个寄存器
                {request = new byte[6];request[0] = deviceAddress;request[1] = functionCode;request[2] = (byte)(registerAddress >> 8);request[3] = (byte)(registerAddress & 0xFF);request[4] = (byte)(value >> 8);request[5] = (byte)(value & 0xFF);}else{throw new ArgumentException($"不支持的功能码: {functionCode}");}// 添加CRC校验byte[] crc = CalculateCRC(request);byte[] fullRequest = new byte[request.Length + 2];Array.Copy(request, fullRequest, request.Length);fullRequest[request.Length] = crc[0];fullRequest[request.Length + 1] = crc[1];// 清空缓冲区
                _serialPort.DiscardInBuffer();_serialPort.DiscardOutBuffer();// 发送请求IoC.Get<MessageManagement>().AddMessage($"Write: {BitConverter.ToString(fullRequest).Replace("-", " ")}");_serialPort.Write(fullRequest, 0, fullRequest.Length);// 异步读取响应return await ReadModbusResponse();}catch (Exception ex){IoC.Get<MessageManagement>().AddMessage($"Modbus通信失败: {ex.Message}", MessageType.警告);return null;}}/// <summary>/// 异步读取Modbus响应/// </summary>private async Task<byte[]> ReadModbusResponse(){await Task.Delay(500); // 等待设备响应
List<byte> response = new List<byte>();DateTime startTime = DateTime.Now;while (DateTime.Now - startTime < TimeSpan.FromMilliseconds(READ_TIMEOUT)){if (_serialPort.BytesToRead > 0){byte[] buffer = new byte[_serialPort.BytesToRead];int bytesRead = _serialPort.Read(buffer, 0, buffer.Length);response.AddRange(buffer.Take(bytesRead));// 检查是否收到完整帧if (response.Count >= 5) // 最小响应长度
                    {// 验证CRCbyte[] receivedData = response.ToArray();byte[] receivedCRC = new byte[] { receivedData[receivedData.Length - 2], receivedData[receivedData.Length - 1] };byte[] calculatedCRC = CalculateCRC(receivedData.Take(receivedData.Length - 2).ToArray());if (receivedCRC[0] == calculatedCRC[0] && receivedCRC[1] == calculatedCRC[1]){return receivedData;}else{IoC.Get<MessageManagement>().AddMessage($"CRC error: {BitConverter.ToString(receivedData).Replace("-", " ")}");}}}await Task.Delay(10);}throw new TimeoutException("读取响应超时");}/// <summary>/// 发送Modbus命令（队列版本）/// </summary>private async Task<byte[]> SendModbusCommand(byte deviceAddress, byte functionCode, ushort registerAddress, ushort value = 0, ushort registerCount = 1){var request = new ModbusRequest{DeviceAddress = deviceAddress,FunctionCode = functionCode,RegisterAddress = registerAddress,Value = value,RegisterCount = registerCount,CompletionSource = new TaskCompletionSource<byte[]>()};// 修复：使用带CancellationToken的WaitToWriteAsyncif (await _requestChannel.Writer.WaitToWriteAsync(_processingCts.Token)){await _requestChannel.Writer.WriteAsync(request, _processingCts.Token);// 使用带超时的Task等待using var timeoutCts = new CancellationTokenSource(TimeSpan.FromSeconds(30));var timeoutTask = Task.Delay(Timeout.Infinite, timeoutCts.Token);var responseTask = request.CompletionSource.Task;var completedTask = await Task.WhenAny(responseTask, timeoutTask);if (completedTask == responseTask){return await responseTask;}else{throw new TimeoutException("Modbus操作超时");}}else{throw new TimeoutException("Modbus请求队列已满");}}/// <summary>/// 读取保持寄存器/// </summary>async private Task<ushort[]> ReadHoldingRegisters(byte deviceAddress, ushort startAddress, ushort registerCount){byte[] response = await SendModbusCommand(deviceAddress, 0x03, startAddress, 0, registerCount);if (response != null && response.Length >= 5 + registerCount * 2){ushort[] result = new ushort[registerCount];for (int i = 0; i < registerCount; i++){int offset = 3 + i * 2;result[i] = (ushort)((response[offset] << 8) | response[offset + 1]);}return result;}return null;}/// <summary>/// 写单个寄存器/// </summary>async private Task<bool> WriteSingleRegister(byte deviceAddress, ushort registerAddress, ushort value){byte[] response = await SendModbusCommand(deviceAddress, 0x06, registerAddress, value);return response != null && response.Length >= 6;}