OpenGL can do threads with shared contexts but caveats apply so it is not popular. But even more common is mapping memory in "OpenGL thread" and then letting a

OpenGL can do threads with shared contexts but caveats apply so it is not popular. But even more common is mapping memory in "OpenGL thread" and then letting another thread fill the memory. Quite common is mapping buffers with persistent/coherent flags at init, and then leave them mapped.