Deadlock

One or more correct

• ABanker's algorithm is used to prevent deadlocks
• BDeadlock formation can be prevented by ensuring that the hold and wait condition is not allowed
• CAn assignment edge in a resource allocation graph is marked from a process to a resource
• DA safe state guarantees that all processes can finish without formation of a deadlock

Numerical answer

One or more correct

• AAborting $P_1$ makes the system deadlock free.
• BAborting $P_3$ makes the system deadlock free.
• CAborting $P_2$ makes the system deadlock free.
• DAborting $P_1$ and $P_4$ makes the system deadlock free.

One or more correct

• ACircular wait is a necessary condition for the formation of deadlock.
• BIn a system where each resource has more than one instance, a cycle in its wait-for graph indicates the presence of a deadlock.
• CIf the current allocation of resources to processes leads the system to unsafe state, then deadlock will necessarily occur.
• DIn the resource-allocation graph of a system, if every edge is an assignment edge, then the system is not in deadlock state.

Answer key coming soon

function OwnResource(Resource R)
    Acquire lock L // a global lock
    if R is available then
        Acquire R
        Release lock L
    else
        if R is owned by another process P then
            Terminate P, after releasing all resources owned by P
            Acquire R
            Restart P
            Release lock L
        end if
    end if
end function

One or more correct

• AThe scheme ensures that deadlocks will not occur.
• BThe scheme may lead to live-lock.
• CThe scheme may lead to starvation.
• DThe scheme violates the mutual exclusion property.

Answer key coming soon

Single correct

• A$X_p + X_q < \text{Min}\{Y_k \mid 1 \leq k \leq n, k \neq p, k \neq q\}$
• B$X_p + X_q < \text{Max}\{Y_k \mid 1 \leq k \leq n, k \neq p, k \neq q\}$
• C$\text{Min}(X_p, X_q) \geq \text{Min}\{Y_k \mid 1 \leq k \leq n, k \neq p, k \neq q\}$
• D$\text{Min}(X_p, X_q) \leq \text{Max}\{Y_k \mid 1 \leq k \leq n, k \neq p, k \neq q\}$

Numerical answer

Single correct

• AThe system is in safe state.
• BThe system is not in safe state, but would be safe if one more instance of E were available
• CThe system is not in safe state, but would be safe if one more instance of F were available
• DThe system is not in safe state, but would be safe if one more instance of G were available

Single correct

• A$x = 1, y = 2$
• B$x = 2, y = 1$
• C$x = 2, y = 2$
• D$x = 1, y = 1$

Answer key coming soon

Single correct

• ASafe, Deadlocked
• BSafe, Not Deadlocked
• CNot Safe, Deadlocked
• DNot Safe, Not Deadlocked

Answer key coming soon

Single correct

• A1
• B2
• C3
• D4

Single correct

• AAny one of I and III but not II or IV
• BAny one of I, III, and IV but not II
• CAny one of II and III but not I or IV
• DAny one of I, II, III, and IV

Single correct

• AOnly REQ1 can be permitted.
• BOnly REQ2 can be permitted.
• CBoth REQ1 and REQ2 can be permitted.
• DNeither REQ1 nor REQ2 can be permitted.

Numerical answer

Single correct

• A$X: P(a)P(b)P(c)\quad Y: P(b)P(c)P(d)\quad Z: P(c)P(d)P(a)$
• B$X: P(b)P(a)P(c)\quad Y: P(b)P(c)P(d)\quad Z: P(a)P(c)P(d)$
• C$X: P(b)P(a)P(c)\quad Y: P(c)P(b)P(d)\quad Z: P(a)P(c)P(d)$
• D$X: P(a)P(b)P(c)\quad Y: P(c)P(b)P(d)\quad Z: P(c)P(d)P(a)$

Answer key coming soon