Difficulty: Easy
Correct Answer: The ability of a single Java process to create and run multiple threads of execution concurrently within the same application, sharing the same memory space
Explanation:
Introduction / Context:
Multithreading is a core feature of Java and is used to build responsive user interfaces, servers that handle many clients, and applications that perform background work without blocking the main flow. While multitasking is about running multiple processes, multithreading focuses on multiple threads within the same process. This question asks you to define multithreading in Java and distinguish it from general operating system multitasking.
Given Data / Assumptions:
Concept / Approach:
Multithreading in Java refers to the capability of a single program to run multiple threads of execution concurrently. Each thread can perform a different task, such as handling a client connection, updating a progress bar, or performing a calculation. Because threads share the same memory, they can communicate efficiently, but they also need careful synchronisation to avoid conflicts. This differs from multitasking, which is about managing multiple independent processes at the operating system level. Multithreading is therefore a finer-grained form of concurrency inside one process.
Step-by-Step Solution:
Step 1: Recognise that a Java application starts with at least one main thread that executes the main method.Step 2: Understand that the program can create additional threads using new Thread(...) or executors, each running its own run method or task.Step 3: Realise that these threads execute concurrently, either truly in parallel on multiple cores or via time-slicing on a single core.Step 4: Note that all threads in the same Java process share the same heap memory and can access common objects, which requires synchronisation mechanisms to avoid race conditions.Step 5: Conclude that multithreading is best described by option A, which emphasises multiple threads within a single application process.
Verification / Alternative check:
You can observe multithreading by writing a Java program that starts several threads, each printing messages with its name. The interleaved output shows concurrent execution. Tools like thread dumps reveal multiple stacks within a single Java process. Documentation on Java concurrency clearly defines multithreading in this way and distinguishes it from operating system multitasking.
Why Other Options Are Wrong:
Option B describes running multiple processes on different machines, which is more related to distributed systems than to multithreading within one Java process. Option C talks about editing and compiling code at the same time, which might involve different tools but does not define multithreading as a concept. Option D describes a database server using a single thread, which is the opposite of multithreaded design. None of these capture the idea of multiple threads inside a single Java application.
Common Pitfalls:
A common pitfall is misusing multithreading to the point of creating too many threads, which leads to context-switching overhead and poor performance. Another mistake is failing to protect shared data, resulting in race conditions, data corruption, or intermittent bugs. Understanding that multithreading is about concurrent execution within one process, and that it requires careful design and synchronisation, is essential for writing robust Java applications.
Final Answer:
Correct answer: The ability of a single Java process to create and run multiple threads of execution concurrently within the same application, sharing the same memory space
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