GATE CS 2024 Set 1 — Question 24

MSQ+1 / -0EasyProcesses & ThreadsOperating SystemUser vs Kernel Threads

Operating System → Processes & Threads → User vs Kernel Threads

Last updated 20 August 2026

Question

Which of the following statements about threads is/are TRUE?

Correct answer (D) Threads belonging to a process are by default not protected from each other Solution To determine which statements are true, let's analyze the properties of threads within a process: 1. Statement (A) is FALSE: Threads can be implemented at the user level (User-Level Threads) using libraries (e.g., Pthreads) or at the kernel level (Kernel-Level Threads) where the OS manages them. Many systems use a hybrid model. 2. Statement (B) is FALSE: Threads within the same process share the process's resources, including the address space, global variables, and the file descriptor table. They do not have individual file descriptor tables. 3. Statement (C) is FALSE: Each thread requires its own execution context, which includes its own program counter, register set, and stack . While they share the heap, they must have separate stacks to manage their own function calls and local variables. 4. Statement (D) is TRUE: Because threads of the same process share the same virtual address space, there is no memory protection between them. One thread can accidentally or intentionally overwrite data being used by another thread. This is why synchronization (like mutexes) is critical in multi-threaded programming. Conclusion: Only statement (D) is correct. Turn this into a strength. Explore AI-powered practice and doubt support with Success Tracker.

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Correct answer (D) Threads belonging to a process are by default not protected from each other Solution To determine which statements are true, let's analyze the properties of threads within a process: 1. Statement (A) is FALSE: Threads can be implemented at the user level (User-Level Threads) using libraries (e.g., Pthreads) or at the kernel level (Kernel-Level Threads) where the OS manages them. Many systems use a hybrid model. 2. Statement (B) is FALSE: Threads within the same process share the process's resources, including the address space, global variables, and the file descriptor table. They do not have individual file descriptor tables. 3. Statement (C) is FALSE: Each thread requires its own execution context, which includes its own program counter, register set, and stack . While they share the heap, they must have separate stacks to manage their own function calls and local variables. 4. Statement (D) is TRUE: Because threads of the same process share the same virtual address space, there is no memory protection between them. One thread can accidentally or intentionally overwrite data being used by another thread. This is why synchronization (like mutexes) is critical in multi-threaded programming. Conclusion: Only statement (D) is correct.

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