OS Foundations Checkpoint

Processes, privilege, and lifecycle invariants.

Get every question correct to pass this checkpoint. You can review feedback, revise your answers, and submit again.

1. In the process-table simulator, PID 2 has a living child PID 3. Exit(2) runs before Wait(1). Which state exists immediately after Exit?

Select one answer.

PID 2 is a zombie and PID 3 has parent 1 Both PIDs are removed immediately PID 3 becomes a zombie and PID 2 keeps running PID 2 is removed but PID 3 keeps parent 2

2. Zombie children of PID 1 are PIDs 7 and 4. Wait(1) is called once. What does the simulator remove?

Select one answer.

PID 7 only Both PIDs Neither, because zombies cannot be reaped PID 4 only

3. A user process asks the kernel to read a file, then resumes in the same process. Which conclusion follows?

Select one answer.

Every system call must create a process A privilege transition need not change which process is running A kernel entry always switches to a different process The caller can bypass access checks because it requested the operation

4. The simulator creates PID 2, exits it, then calls Fork(2) before it is reaped. What integer is returned?

5. PID3 is already a zombie child of PID2. Exit(2) runs. Which state must PID3 have? Select one answer.

Select one answer.

Removed immediately Living with parent1 Zombie permanently attached to PID2 Zombie with parent1

6. Fork(1) creates2; Exit(2); Wait(1); Fork(2) fails. What does the next Fork(1) return? Enter one integer.

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