I'm sorry i'm 65 and a newby and I don't know what a thread is.What is a thread??
You can use an HDMI switcher splitter, like this one from Amazon. Plug the single end into your TV, the other devices into the end with the 3 HDMI ports, and it automatically switches to the correct port depending on which device you turn on. I've used it for years without any problems when I had an older single HDMI port TV. I'm assuming your Roku box has a USB port on it, it will work through the Roku.