Pattern Design Concurrency Patterns 1

Question 1

What is the primary purpose of the Active Object pattern in concurrent programming?

Accepted Answer

To decouple method execution from method invocation for objects that reside in their own thread of control

Answer

The Active Object pattern decouples method invocation from execution by running the object in its own thread and using a request queue to buffer calls.

Question 2

Which concurrency pattern ensures that only one thread can execute a critical section at a time by combining mutual exclusion with condition synchronization?

Accepted Answer

Monitor Object

Answer

The Monitor Object pattern synchronizes concurrent method execution by combining a mutual exclusion lock with condition variables within a single object.

Question 3

The Thread Pool pattern is primarily used to:

Accepted Answer

Limit the number of concurrent threads and reuse them across multiple tasks

Answer

Thread Pool limits thread creation overhead by maintaining a fixed set of reusable threads that pick up tasks from a shared work queue.

Question 4

Which pattern uses a shared queue to pass work items between threads that produce data and threads that consume it?

Accepted Answer

Producer-Consumer

Answer

The Producer-Consumer pattern decouples producers and consumers by having them communicate through a bounded or unbounded shared queue.

Question 5

The Read-Write Lock pattern allows:

Accepted Answer

Multiple readers simultaneously but only one writer at a time, with writers excluding all readers

Answer

A Read-Write Lock grants concurrent access to multiple readers but ensures exclusive access for writers, improving throughput for read-heavy workloads.

Pattern Design Practice Test

Pattern Design Practice Test

Pattern Design Concurrency Patterns 1