static void clear_evtchn_to_irq_row(unsigned row)
{
	unsigned col;

	for (col = 0; col < EVTCHN_PER_ROW; col++)
		WRITE_ONCE(evtchn_to_irq[row][col], -1);
}
The program contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently.