增加在windows打开设备时的多设备多通道支持

Author: STAY COOL

README.md

@@ -85,17 +85,71 @@ channels = can.detect_available_configs('candle')
 print(channels)
 ```
 
+### Open multiple channels of a single device
+
+This driver now supports opening multiple channels from the same device in a single `CandleBus` instance.
+
+- Pass a list of channels belonging to the same device, e.g. `['SERIAL:0', 'SERIAL:1']`.
+- Alternatively, pass a list of indices with `serial_number=SERIAL`.
+- A single instance must NOT mix channels from different devices.
+
+```python
+import can
+from candle import CandleBus
+
+# Option A: list of "serial:idx" strings
+bus = CandleBus(channel=['208233AD5003:0', '208233AD5003:1'], fd=True, bitrate=1000000, data_bitrate=5000000, loop_back=True)
+
+# Option B: list of indices with explicit serial number
+bus = CandleBus(channel=[0, 1], serial_number='208233AD5003', fd=True, bitrate=1000000, data_bitrate=5000000, loop_back=True)
+
+# Send to a specific channel by setting msg.channel
+m0 = can.Message(arbitration_id=0x100, data=b'\x00'*8, is_fd=True)
+m0.channel = 0
+bus.send(m0)
+
+m1 = can.Message(arbitration_id=0x101, data=b'\x01'*8, is_fd=True)
+m1.channel = 1
+bus.send(m1)
+
+# Receive frames: msg.channel indicates the source channel
+rx = bus.recv(timeout=0.5)
+print(rx.channel, hex(rx.arbitration_id))
+
+bus.shutdown()
+```
+
+### Notes on multi-channel behavior
+
+- A single `CandleBus` instance manages multiple channels of one device using one device handle.
+- `send()` routes frames to the target channel based on `msg.channel` (int, `"SERIAL:idx"`, or `"idx"`).
+- `recv()` returns `Message.channel` set to the source channel number.
+- When `msg.channel` is not set, `send()` defaults to the first managed channel.
+- To test multiple devices simultaneously, create one `CandleBus` per device.
+
+### Backward compatibility
+
+- Existing single-channel usage is unchanged; `channel=0` or `channel='SERIAL:0'` still works.
+- `can.detect_available_configs('candle')` continues to report channels as `serial:idx` strings.
+- The stress test `python -m candle.stress` (single-channel) remains compatible.
+
 ### Performance
 
-The communication layer is implemented based on pybind11 with libusb. You can run the following script to evaluate the performance.
+The communication layer is implemented based on pybind11 with libusb. You can run the following scripts to evaluate the performance.
 
+For single-channel performance:
 ```shell
 python -m candle.stress
 ```
 
+For multi-channel and multi-device performance and correctness verification:
+```shell
+python -m candle.stress_multichannel
+```
+
 ## Reference
 
 - [linux gs_usb driver](https://github.com/torvalds/linux/blob/master/drivers/net/can/usb/gs_usb.c)
 - [python gs_usb driver](https://github.com/jxltom/gs_usb)
 - [candleLight firmware](https://github.com/candle-usb/candleLight_fw)
-- [candle_api](https://github.com/BIRLab/candle_api)
+- [candle_api](https://github.com/BIRLab/candle_api)