CS 143A Quiz 1 Solution

7) Threads of the same task have the following characteristics: (I) Share the same address space, (II) Reduce context switching overhead; (III) Are protected from each other the same way as processes. Which thread characteristics are correct? a. I, II, III b. I, III c. I, II 8) Which of the following are true about traps and interrupts: a. Other interrupts are enabled when an interrupt routine runs b. Traps are usually generated by hardware c. The CPU allows the currently running process to finish its currently executing function before it switches to an interrupt d. None of the above 9) What system command spawns a child process that has a copy of each parent process local variable? a. clone() b. spawn() c. fork() d. child() 10) A preemptive scheduling algorithm will: a. Insert a process before another in the waiting queue b. Stop a process temporarily and run another in the queue c. Have prior knowledge of how long a set of processes will take to run and schedule them perfectly 1) To protect itself a typical operating system provides: a. Access modes (privileged and user) b. Encryption c. Sealed Cases d. Hidden Files 2) Secondary storage is used because a. Main memory is too slow b. Main memory is volatile c. Main memory is obsolete 3) Synchronous I/O means a. CPU starts the transfer and goes off to do something else until interrupt arrives b. CPU starts the transfer and waits until the transfer is finished c. None of the above 4) Stack Pointer is a. Included in a process control block b. Stored on disk in the header of a file c. Received from a web client 5) Program Counter represents the following information a. Address of the Memory Base Information b. Address of the Process Identification (PID) c. Address of the Next Instruction 6) A process gets from “Running” state to “Waiting” state if a. Process runs out of time slice (quantum) b. Process calls a ‘read’ system call c. Process calls an ‘exit’ system call