An example of OnUpdate throttling in WoW.

OnUpdate_Throttle_Example.lua

local frame = CreateFrame("Frame")

-- The minimum number of seconds between each update
local ONUPDATE_INTERVAL = 0.1

-- The number of seconds since the last update
local TimeSinceLastUpdate = 0
frame:SetScript("OnUpdate", function(self, elapsed)
	TimeSinceLastUpdate = TimeSinceLastUpdate + elapsed
	if TimeSinceLastUpdate >= ONUPDATE_INTERVAL then
		TimeSinceLastUpdate = 0
		
		-- Do stuff
	end
end)

-- When the frame is shown, reset the update timer
frame:SetScript("OnShow", function(self)
	TimeSinceLastUpdate = 0
end)