Consider the following psudocode.

int x;

P$1()\{$

compare$\_$and$\_$swap$($x$,$compare$\_$and$\_$swap$($x$,1,2),1)$;

$\}$

P$2()\{$

int y $=9$;

exchange$($x$,$y$)$;

exchange$($y$,$x$)$;

$\}$

main$()\{$

x $=0$;

P$1()$;

P$2()$;

$\}$

What are the possible values of x after P$1$ and P$2$ finish?

$0,1$

$0,2$

$9,2$