Problem $7[$Consistency and Synchronization$](10$ pts$.)$

In the following code snippet, what are the possible outcomes?

$R1,R2$ and $R3$ are registers in threads $T0$ and $T1.R0$ always contains value $0.A,B$

and lock are shared$-$memory addresses. T&S is an instruction that atomically returns

the value in lock and stores $1$ in lock.

To answer this questions give all the possible values of R$1,$ R$2$ and R$3$ in T$0$ and T$1$

at the end of the execution.