Thread creation and management in Operating Systems - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Thread Creation Methods

Which of the following is not a common method to create a thread in an operating system?

A Creating a thread by specifying a function to execute

B Using a thread library function like pthread_create()

C Cloning an existing process with fork()

D Using a thread class constructor in high-level languages

💡 Hint

Think about the difference between processes and threads.

fork() creates a new process, not a thread. Threads share the same process space, while fork() duplicates the entire process.

📋 Factual

intermediate

Thread Lifecycle States

Which of the following is not a typical state in a thread's lifecycle?

A Zombie

B Sleeping

C Running

D Waiting

💡 Hint

Consider which states apply to threads versus processes.

Zombie state applies to processes that have finished execution but still have an entry in the process table. Threads do not have a zombie state.

🔍 Analysis

advanced

Effect of Thread Priority on Scheduling

Consider a system where threads have priorities. If a high-priority thread is ready to run, what is the most likely behavior of the scheduler?

A It will always run the high-priority thread immediately, preempting any running lower-priority thread.

B It will wait for the current thread to finish before running the high-priority thread.

C It will run threads in the order they were created, ignoring priority.

D It will randomly select any thread to run regardless of priority.

💡 Hint

Think about preemptive scheduling and priority.

In priority-based preemptive scheduling, the scheduler interrupts lower-priority threads to run higher-priority ones immediately.

❓ Comparison

advanced

User-Level vs Kernel-Level Threads

Which statement correctly compares user-level threads and kernel-level threads?

A Kernel-level threads cannot run in parallel on multiple processors.

B Kernel-level threads can be scheduled independently by the OS, but user-level threads cannot.

C User-level threads require more overhead to switch than kernel-level threads.

D User-level threads are managed by the kernel, while kernel-level threads are managed by user libraries.

💡 Hint

Consider who manages the threads and how scheduling works.

Kernel-level threads are managed and scheduled by the OS kernel independently. User-level threads are managed by user libraries and the kernel sees them as a single process thread.

❓ Reasoning

expert

Deadlock Scenario in Thread Management

Given two threads T1 and T2 and two resources R1 and R2, which scenario can cause a deadlock?

Assume each thread locks one resource and waits for the other.

A T1 and T2 both wait for R1 without locking any resource.

B T1 locks R1, then releases it before locking R2; T2 locks R2 and then locks R1.

C T1 locks R1 and R2 sequentially without waiting; T2 waits for R1 only.

D T1 locks R1, T2 locks R2, then T1 waits for R2 and T2 waits for R1.

💡 Hint

Deadlock happens when threads wait on each other holding resources.

In option D, T1 holds R1 and waits for R2 while T2 holds R2 and waits for R1, causing a circular wait and deadlock.