setImmediate()

setImmediate(callback[, arg][, ...])

Schedules "immediate" execution of callback after I/O events' callbacks and before timers set by setTimeout and setInterval are triggered. Returns an immediateObject for possible use with clearImmediate. Additional optional arguments may be passed to the callback.

Callbacks for immediates are queued in the order in which they were created. The entire callback queue is processed every event loop iteration. If an immediate is queued from inside an executing callback, that immediate won't fire until the next event loop iteration.