日志输出，空指针导致程序出错,重写释放逻辑

handler/tool.go

@@ -164,7 +164,8 @@ func subscribeAndHandleMessagesV3(ws *websocket.Conn, device_id int) {
 	t_count := 0
 	for {
 		//从service获取当前帧
-		img, c := service.GetDeviceCurrentFrame(device_id)
+		var img gocv.Mat
+		c := service.GetDeviceCurrentFrameV2(&img, device_id)
 		if c != count {
 			//将img转[]byte
 			if img.Empty() {

service/tool.go

@@ -51,6 +51,47 @@ func SetDeviceCurrentFrame(frame gocv.Mat, device_id int) error {
 	return nil
 }
 
+func GetDeviceCurrentFrameV2(frame *gocv.Mat, deviceId int) int {
+	defer func() {
+		if err := recover(); err != nil {
+			log.Printf("设备:%d 错误: %v\n", deviceId, err)
+		}
+	}()
+	//获取读写锁
+	mutex_, ok := DeviceRWMap.Load(deviceId)
+	if !ok {
+		log.Printf("DeviceRWMap 读写锁不存在，device_id: %d \n", deviceId)
+		return -1
+	}
+	mutex, ok := mutex_.(*sync.RWMutex)
+	if !ok {
+		log.Printf("DeviceRWMap 存储的不是 *sync.RWMutex 类型，device_id: %d \n", deviceId)
+		return -1
+	}
+	mutex.RLock()
+	defer mutex.RUnlock()
+	var frame_ gocv.Mat
+	//获取当前帧
+	frameIface, ok := DeviceCurrentFrameMap.Load(deviceId)
+	if !ok {
+		return -1
+	}
+	frame_, ok = frameIface.(gocv.Mat)
+	if !ok {
+		log.Printf("DeviceCurrentFrameMap 存储的不是 gocv.Mat 类型，device_id: %d \n", deviceId)
+	}
+	*frame = frame_
+	frame_countIface, ok := DeviceFrameCount.Load(deviceId)
+	if !ok {
+		return -1
+	}
+	frame_count, ok := frame_countIface.(int)
+	if !ok {
+		log.Printf("DeviceFrameCount 存储的不是 int 类型，device_id: %d", deviceId)
+	}
+	return frame_count
+}
+
 func GetDeviceCurrentFrame(deviceId int) (gocv.Mat, int) {
 	defer func() {
 		if err := recover(); err != nil {