Chapter 13 Rev Qs

Question 1

Write at least two mechanisms that controls the order in which tasks are executed in concurrency programs.

Answer 1

Task Synchronization:
two kinds; task communication is necessary and provided by shared nonlocal variables, parameters, and message passing
Scheduler:
maps task execution onto available processors
—-
Semaphores; Monitors; Message Passing

Question 2

Name at least three programming languages presented in class that support concurrency.

Answer 2

ADA, Scala, Javascript, Rust, GO, Haskell

Question 3

What is the difference of physical concurrency and logical concurrency?

Answer 3

Physical Concurrency:
multiple independent processors
Logical Concurrency:
the appearance of physical concurrency is presented by time-sharing one processor (SW can be designed as if there were multiple threads of control)

Question 4

Describe the two types of synchronization in concurrency. Cooperation and Competition.

Answer 4

Cooperation:
Task A must wait for Task B to complete some specific activity before Task A can continue its execution. (The producer-consumer problem)
Competition:
Two or more tasks must use some resource that cannot be simultaneously used(A shared computer; is usually provided by mutually exclusive access)