Collectgarbage

 collectgarbage (opt [, arg])

This function is a generic interface to the garbage collector. It performs different functions according to its first argument, opt:

• "stop": stops the garbage collector.
• "restart": restarts the garbage collector.
• "collect": performs a full garbage-collection cycle.
• "count": returns the total memory in use by Lua (in Kbytes).
• "step": performs a garbage-collection step. The step "size" is controlled by arg (larger values mean more steps) in a non-specified way. If you want to control the step size you must experimentally tune the value of arg. Returns true if the step finished a collection cycle.
• "setpause": sets arg as the new value for the pause of the collector (see §2.10). Returns the previous value for pause.
• "setstepmul": sets arg as the new value for the step multiplier of the collector (see §2.10). Returns the previous value for step.