Patterns interview questions

12 real Patterns questions from the Concurrency bank, as asked in Indian campus drives and tech interviews. Every question has a verified answer and an AI-tutor explanation on placd — free to start.

1. What is Immutability?

Mid
  1. A.an optimization that tests a condition before and after acquiring a lock to avoid synchronization on the common already-initialized path
  2. B.restricting access to an object to a single thread so it needs no synchronization because nothing else can touch it
  3. C.a facility giving each thread its own private copy of a variable, eliminating sharing-related contention for per-thread data
  4. D.designing objects so their state never changes after construction, making them inherently safe to share across threads without locks
Reveal the answer + AI explanation — free account

2. Which term means: "designing objects so their state never changes after construction, making them inherently safe to share across threads without locks"?

Mid
  1. A.Thread-local storage
  2. B.Immutability
  3. C.Thread confinement
  4. D.Double-checked locking
Reveal the answer + AI explanation — free account

3. Which statement is correct?

Mid
  1. A.Immutability — an optimization that tests a condition before and after acquiring a lock to avoid synchronization on the common already-initialized path
  2. B.Immutability — designing objects so their state never changes after construction, making them inherently safe to share across threads without locks
  3. C.Immutability — a facility giving each thread its own private copy of a variable, eliminating sharing-related contention for per-thread data
  4. D.Immutability — restricting access to an object to a single thread so it needs no synchronization because nothing else can touch it
Reveal the answer + AI explanation — free account

4. What is Thread confinement?

Mid
  1. A.a facility giving each thread its own private copy of a variable, eliminating sharing-related contention for per-thread data
  2. B.restricting access to an object to a single thread so it needs no synchronization because nothing else can touch it
  3. C.an optimization that tests a condition before and after acquiring a lock to avoid synchronization on the common already-initialized path
  4. D.designing objects so their state never changes after construction, making them inherently safe to share across threads without locks
Reveal the answer + AI explanation — free account

5. Which term means: "restricting access to an object to a single thread so it needs no synchronization because nothing else can touch it"?

Mid
  1. A.Immutability
  2. B.Double-checked locking
  3. C.Thread confinement
  4. D.Thread-local storage
Reveal the answer + AI explanation — free account

6. Which statement is correct?

Mid
  1. A.Thread confinement — restricting access to an object to a single thread so it needs no synchronization because nothing else can touch it
  2. B.Thread confinement — designing objects so their state never changes after construction, making them inherently safe to share across threads without locks
  3. C.Thread confinement — an optimization that tests a condition before and after acquiring a lock to avoid synchronization on the common already-initialized path
  4. D.Thread confinement — a facility giving each thread its own private copy of a variable, eliminating sharing-related contention for per-thread data
Reveal the answer + AI explanation — free account

7. What is Double-checked locking?

Senior
  1. A.a facility giving each thread its own private copy of a variable, eliminating sharing-related contention for per-thread data
  2. B.designing objects so their state never changes after construction, making them inherently safe to share across threads without locks
  3. C.an optimization that tests a condition before and after acquiring a lock to avoid synchronization on the common already-initialized path
  4. D.restricting access to an object to a single thread so it needs no synchronization because nothing else can touch it
Reveal the answer + AI explanation — free account

8. Which term means: "an optimization that tests a condition before and after acquiring a lock to avoid synchronization on the common already-initialized path"?

Senior
  1. A.Thread-local storage
  2. B.Thread confinement
  3. C.Immutability
  4. D.Double-checked locking
Reveal the answer + AI explanation — free account

9. Which statement is correct?

Senior
  1. A.Double-checked locking — restricting access to an object to a single thread so it needs no synchronization because nothing else can touch it
  2. B.Double-checked locking — designing objects so their state never changes after construction, making them inherently safe to share across threads without locks
  3. C.Double-checked locking — an optimization that tests a condition before and after acquiring a lock to avoid synchronization on the common already-initialized path
  4. D.Double-checked locking — a facility giving each thread its own private copy of a variable, eliminating sharing-related contention for per-thread data
Reveal the answer + AI explanation — free account

10. What is Thread-local storage?

Mid
  1. A.designing objects so their state never changes after construction, making them inherently safe to share across threads without locks
  2. B.an optimization that tests a condition before and after acquiring a lock to avoid synchronization on the common already-initialized path
  3. C.restricting access to an object to a single thread so it needs no synchronization because nothing else can touch it
  4. D.a facility giving each thread its own private copy of a variable, eliminating sharing-related contention for per-thread data
Reveal the answer + AI explanation — free account

11. Which term means: "a facility giving each thread its own private copy of a variable, eliminating sharing-related contention for per-thread data"?

Mid
  1. A.Double-checked locking
  2. B.Thread-local storage
  3. C.Immutability
  4. D.Thread confinement
Reveal the answer + AI explanation — free account

12. Which statement is correct?

Mid
  1. A.Thread-local storage — designing objects so their state never changes after construction, making them inherently safe to share across threads without locks
  2. B.Thread-local storage — an optimization that tests a condition before and after acquiring a lock to avoid synchronization on the common already-initialized path
  3. C.Thread-local storage — restricting access to an object to a single thread so it needs no synchronization because nothing else can touch it
  4. D.Thread-local storage — a facility giving each thread its own private copy of a variable, eliminating sharing-related contention for per-thread data
Reveal the answer + AI explanation — free account

Free to start

Answers, AI explanations, and a scored voice mock interview

Sign up free to check your answers with explanations, ask the AI tutor anything on any question, and take one full AI mock interview — scored like a real panel.

Practice Patterns free