Figure 2.11 illustrates the concurrent execution of four communicating processes $\left(P_1, P_2, P_3\right.$ and $\left.P_4\right)$ and their associated recovery points (for example, $R_{11}$ is the first recovery point for process $P_1$ ).
GRAPH CAN'T COPY.
Explain what happens when an error is detected by:
- Process $P_1$ at time $t$;
- Process $P_2$ at time $t$.