$(30$ points$)$ Multiple Choices

Write your answers in the boxes below:

$(1)$ Which of the following resources cannot be shared across all the threads in the same process P $?$

A$)$ The global variables.

B$)$ An open file in $P.$

C$)$ The text.

D$)$ The stack memory.

$(2)$ Which of the following statements on pipe communication is TRUE?

A$)$ Named pipes are automatically deleted after the communication ends.

B$)$ Communications are uni$-$directional for ordinary pipes

C$)$ Named pipes cannot be used among a parent and child process.

D$)$ Ordinary pipes can be used by communicating processes on different machines.

$(3)$ If an application is $50\%$ parallel and $50\%$ serial, which of the following values is a possible speedup when moving the application from one core to four cores, according to Amdahl's Law?

A$)1\mathrm{.}6$

B$)2\mathrm{.}0$

C$)2\mathrm{.}4$

D$)2\mathrm{.}8$

$(4)$ Which of the following statements is NOT TRUE between user threads and kernel threads?

A$)$ User threads are only visible to programs

B$)$ A user thread needs to be mapped a kernel thread before execution

C$)$ Many$-$to$-$one mapping has been widely adopted by modern OS

D$)$ OS manages kernel threads including allocating the required resources

$(5)$ Which of the following process scheduling algorithm may lead to starvation?

A$)$ FIFO

B$)$ Shortest Job First

C$)$ Round Robin

D$)$ None of the above

$(6)$ Which of the following process scheduling is considered non$-$preemptive?

Switches from running to waiting

Switches from running to ready

Switches from waiting to ready

Process terminates

A$)1$ and $2$

B$)1$ and $4$

C$)2$ and $3$

D$)1,2$ and $3$

$(7)$ Which of the following statement about the time quantum in RR algorithm is TRUE?

A$)$ The time quantum can be as small as possible to achieve high average response time

B$)$ The RR algorithm never suffers from convoy effect no matter how to set the time quantum

C$)$ The average job turn$-$around time of RR might be worse than FCFS no matter how we set the time quantum

D$)$ None of the above

$(8)$ Which of the following statement on MLFQ scheduling is TRUE?

A$)$ It is fair in the sense that all CPU$-$bound processes can make progress

B$)$ It might deliver better performance than $RR$

C$)$ Its performance resembles SJF and SRTF scheduling without the need to estimate the next CPU burst time

D$)$ All of the above

$(9)$ Under symmetric multiprocessing, or SMP$,$ what is the advantage of using per$-$core ready queue, i$.$e$.,$ each CPU core has its own ready queue$($s$)?$

A$)$ It provides better CPU utilization in all cases

B$)$ It naturally provides processor affinity

C$)$ It makes CPU scheduling easier

D$)$ None of the above

$(10)$ Which of the following statement of rate$-$monotonic and EDF scheduling is TRUE?

A$)$ A static priority is assigned in rate$-$monotonic scheduling

B$)$ The rate$-$monotonic scheduling algorithm follows a non$-$preemption method

C$)$ EDC scheduling uses static priority

D$)$ Both rate$-$monotonic and EDF scheduling require processes to be periodic