Multithreading: Exam Questions

• Which of the following statements about threads is true? (Wrong answers are subtracted from correct answers.)

  • A thread shares an address space with all other threads in a process.

  • Threads are an operating system’s way of keeping track of all the events that happen while a system is running.

  • A thread’s memory is isolated from all other threads in the system.

  • When a program starts, the process is made up of one initial thread, the main thread

  • Threads are a way of achieving parallel execution within the same address space.

• What can happen when two threads modify the same integer at the same time (for example using a plain “+” operator in most programming languages)? (One answer.)

  • One of the modifications might be lost.

  • Everything will be ok.

• Which of the following statements about race conditions is true? (Wrong answers are subtracted from correct answers.)

  • Two or more threads execute a loop, and it is not entirely clear which one finishes first.

  • It is a race condition if two or more threads access the same data at the same time, without providing any protection for potentially overlapping non-atomic operations.

• What device is usually used to prevent race conditions? (One answer.)

  • A mutex

  • Character device