Session 7

What is the "immutability" approach in terms of managing parallel programs?

• Only using one thread

• Not having data that changes

• Different threads only access different data

• Only using Atomics

What is mutual exclusion?

• Different threads only access different data

• Having all shared ressources as read only

• Only one thread can access a shared ressource at a time

• Not using both locks and synchronized blocks in the same programm

What happens if a thread calls .lock() on a ReentrantLock it already has?

• We get a runtime error

• The program doesn't compile

• It increments the count of the lock by 1 and moves on

• The thread waits forever

If a thread locks the same Java ReentrantLock twice, you have to unlock twice as well.

• True

• False

What is coarse-grained locking and what are its advantages?

• Using one lock for many objects; Simpler to implement

• Using one lock for each object; More simultaneous access possible

• Using many locks for one object; Safer than just one lock

• Using one lock for many objects; More simultaneous access possible

You can't have bad interleavings on a machine with only one processor.

• True

• False

Bad interleavings and Data Races are the same.

• True

• False