Concurrency

Question 1

what is mutual exclusion?

Answer 1

when only one process may be executing in the critical section

Question 2

what is lockout?

Answer 2

a process blocked from entering a critical section due to another process

Question 3

what is starvation?

Answer 3

when a group of processes continually enters the critical section preventing others from entering the critical section

Question 4

what is a deadlock?

Answer 4

when processes block each other indefinitely from entering the critical section

Question 5

what is a mutex lock?

Answer 5

mutex locks protect critical sections to prevent race conditions

Question 6

what is the difference between a contended and uncontended lock?

Answer 6

when a process goes to access a lock, if it’s available it’s uncontended

Question 7

what advantage to spinlocks have?

Answer 7

although the process is “spinning” waiting for a lock to become available, it does not have to context switch which has upside

Question 8

what is a semaphore?

Answer 8

a general purpose primitive that allows solving synchronization problems. a binary semaphore would be a mutex lock for example

Question 9

what are monitors?

Answer 9

monitors are a wrapper around things like semaphores that basically handle things like requesting and releasing