are you talking about indoors or outdoors if indoors u control the light eventuly it probably would stop growing when u ran out of room imo. Outdoors it would go thru the whole life cycle veg, bud then die after budding.
A plant will grow forever until it gets root bound if kept indoor, youtube how to prune weed and see a guy who made a bonsai bush like mother that got so big he had to put it in a rubbermaid heavy duty garbage can.