Select whether each of the following statements is True or False. Imprecise Interrupts are less complex to implement/handle than Precise Interrupts. [1] “Masking” is a strategy used to manage multiple interrupts. [2] Once the interrupt is handled successfully, the process that caused the interrupt is executed immediately. [3]  Interrupts are invoked at pre-defined moments in time. The developer must decide when interrupts will happen. [4]

Which of the following are valid roles and responsibilities of an OS? Select True or False.    1. Providing a user interface. The user interface is always a component of the OS. In other words, the interface is the OS. [1] 2. Supplying system tools to facilitate program development. [2] 3. Serving as an extended machine to provide users with a simpler model of a computer. [3] 4. Be a resource manager for processes, memory, and I/O devices. [4]

Select which of the following are true for kernel space threads: Processes running in user space may spawn kernel threads without making a system call. [1] Kernel threads may be blocked individually. [2] Implementations of kernel threads are OS specific. [3] A thread table in user space contains information about kernel threads. [4] Both system and procedure calls may manage kernel threads [5]

Match each of the following process segments with their content:

Identify whether the following statements apply to the producer-consumer problem, the readers-writers problem, neither, or both. 1. This strategy involves a finite data buffer. [1]  2. A proposed solution involves semaphores. [2]  3. A proposed solution involves alpha locks. [3]  4. Otherwise known as the persistent database problem. [4] 

Select which scheduler corresponds to each statement: 1. The goal is to maximize throughput [1] 2. One of its constraints involves being lightweight [6] 3. Also called the memory scheduler[3] 4. Decided what remains in memory and what gets placed back into storage[4] 5. Generally not used in interactive operating systems  [2] 6. Decide which process gets to be executed next in the CPU[5]

Select whether each of the statements is true for preemptive scheduling algorithms, non-preemptive scheduling algorithms, both, or neither. This class of scheduling algorithms minimizes the number of process/context switches that occur. [1] More suited for interactive operating systems serving and interacting with many users. [2] Always invokes a scheduler when a process is killed or removed/preempted from the CPU. [3] Historically, appeared later in interactive operating systems for personal computers. [4]

Which of the following are properties of user-space threads, kernel-space threads, both or neither? In a multicore system, this type of threading can’t execute multiple threads from the same process at the same time. [1] This type of thread is created with a non-OS-native API. [2]  This type of thread has its own program counter and state. [3]  This type of thread can be scheduled by an OS-independent algorithm. [4]  When using this type of thread, threads belonging to the same process share the same stack. [5] 

Given the following batch jobs Calculate the mean turnaround time (MTT) using the Shortest Job First non-preemptive scheduling algorithm. Answer with a number. For example “3.45” or “3”. Priority 0 is the lowest priority.

Consider the following pseudocode for threads that communicate using a linux pipe (message passing). What is the order that the functions (e.g. horse(), cat(), etc) run in? Note that, with Pipes, the receiving operation blocks the thread until the message is received.   pipe pipe1 = new Pipe(); pipe pipe2 = new Pipe();   void thread1() {      receive_from_pipe(pipe1);      zebra();      write_to_pipe(pipe2, “msg1”);      receive_from_pipe(pipe1);      horse();      waterfall();      write_to_pipe(pipe1, “msg3”);      receive_from_pipe(pipe1); }   void thread2() {      dog();      write_to_pipe(pipe1, “msg2”);      receive_from_pipe(pipe2);      cat();      write_to_pipe(pipe1, “msg4”); }