Quiz 3

Question 1

T/F: Concurrency means that several tasks run at the same time interval. Parallelism means that several tasks run at the same instant time

Answer 1

True

Question 2

Which of the following statements is not correct about threads and processes:
- Switching between processes is cheaper than switching between threads within a process.
- If one thread fails with an error/exception and is not managed, the whole process will fail.
- The address space of a process is shared among all its thread

Answer 2

If one thread fails with an error/exception and is not managed, the whole process will fail.

Question 3

Which of the following statements are correct:
- If a user-level thread is waiting for I/O, the entire process will wait.
- The kernel-level threads can be managed by the user.
- The OS can schedule the kernel-level threads.
- The OS can schedule the user-level threads.

Answer 3

• The kernel-level threads can be managed by the user.
• The OS can schedule the kernel-level threads.

Question 4

Assume we have a global variable total initialized as 0. Two threads are executing addFifty() concurrently. What is the value of total when both threads finish their execution?

int total = 0;
void *addFifty() {
for (int i = 0; i < 50; i++)
total += 1;
}

Answer 4

100

Question 5

Which of the following statements is not correct:
- A process can create one or more processes.
- A thread can create one or more processes.
- A process can create one or more threads.

Answer 5

A thread can create one or more processes.

Question 6

T/F: Only threads can block independently from one another.

Answer 6

False

Question 7

___ is the default thread cancellation type for threads

Answer 7

defferred

Question 8

In a web server that uses multithreading to continuously listen to user requests as well as handle each individual request simultaneously, will you prefer using synchronous or asynchronous threading strategies?

Answer 8

asynchronous

Question 9

In the Many to One model, multiple threads are unable to run in parallel on multiprocessors because

Answer 9

only one thread can access the kernel at a time

Question 10

T/F : Threads are faster to create and destroy than processes.

Answer 10

True

Question 11

T/F: In a multi-threaded process, the PCB is replaced by multiple TCBs.

Answer 11

False

Question 12

Using n threads within a single process is more efficient than using n separate processes because

Answer 12

the threads share the same code and data

Question 13

T/F: Consider N threads in a process. If one thread passes certain arguments to a function in the program, are these arguments visible to the other threads?

Answer 13

False

Question 14

In the Many-to-One model, multiple threads are unable to run in parallel on multiprocessors because

Answer 14

only one thread can access the kernel at a time

Question 15

what is the drawback of the One-to-One Model?

Answer 15

creating a user thread requires creating the corresponding kernel thread