Pattern Design Concurrency Patterns 2

Question 1

The Half-Sync/Half-Async pattern separates:

Accepted Answer

Synchronous and asynchronous processing into distinct architectural layers

Answer

Read and write operations into different dedicated threads

Answer

Producers from consumers using a message-passing pipeline

Answer

UI rendering threads from background computation threads

Question 2

Which concurrency construct is used to block a set of threads until all of them have reached a common synchronization point before any can continue?

Accepted Answer

Barrier

Answer

Singleton

Answer

Factory Method

Answer

Observer

Question 3

The Reactor pattern is most commonly used for:

Accepted Answer

Event-driven I/O handling that multiplexes and dispatches service requests from concurrent connections

Answer

Creating objects without specifying their concrete class at compile time

Answer

Assigning dynamic thread priorities based on system load

Answer

Pooling and reusing database connections across application threads

Question 4

In the Thread-Specific Storage (Thread-Local Storage) pattern, each thread has:

Accepted Answer

Its own independent copy of a variable, invisible to other threads

Answer

A dedicated CPU core assigned to it by the operating system

Answer

A shared lock it must acquire before reading shared memory

Answer

A private event queue for dispatching incoming work items

Question 5

Which concurrency pattern is specifically designed to ensure a lazily initialized shared resource is created exactly once in a multithreaded environment while minimizing locking overhead?

Accepted Answer

Double-Checked Locking

Answer

Producer-Consumer

Answer

Thread Pool

Answer

Active Object

Question 6

The Balking pattern causes an object to:

Accepted Answer

Reject (balk at) an operation outright if the object is not in an appropriate state to handle it

Answer

Block the calling thread until a prerequisite condition becomes true

Answer

Distribute pending work items evenly across a pool of worker threads

Answer

Notify other threads via a signal when an asynchronous task completes

Question 7

What problem does the Guarded Suspension pattern solve?

Accepted Answer

It suspends the calling thread until a necessary precondition is true before allowing an operation to proceed

Answer

It prevents race conditions by temporarily disabling thread scheduling interrupts

Answer

It ensures that only one instance of a class is created across all threads

Answer

It governs memory allocation strategies in multithreaded applications