go/state.go
func (s *State) Push() bool {
	//attempt to mark state as 'pushing'
	if atomic.CompareAndSwapUint32(&s.push.ing, 0, 1) {
		go s.gopush()
		return true
	}
	//if already pushing, mark queued
	atomic.StoreUint32(&s.push.queued, 1)
	return false
}
func (s *State) Push() bool {
	//attempt to mark state as 'pushing'
	if atomic.CompareAndSwapUint32(&s.push.ing, 0, 1) {
		go s.gopush()
		return true
	}
	//if already pushing, mark queued
	atomic.StoreUint32(&s.push.queued, 1)
	return false
}
//Push the changes from this object to all connected clients.
//Push is thread-safe and is throttled so it can be called
//with abandon. Returns false if a Push is already in progress.