What is hyper-threading?

Intel’s hyper-threading technology enables a single physical CPU core to function as two logical cores. Through the use of idle core resources, it allows a single core to operate several threads simultaneously.

What is thread granularity?

Thread granularity refers to the level of subdivision of tasks among threads:

• Fine-Grained Threads: Smaller tasks, more threads.
• Coarse-Grained Threads: Larger tasks, fewer threads. Choosing the granularity depends on the balance between overhead and performance.

What is the difference between multithreading and multitasking?

• Multithreading: Multiple threads execute within the same process.
• Multitasking: Multiple processes execute concurrently, which may involve multithreading within those processes.

What is thread starvation vs. deadlock?

• Thread Starvation: A thread is perpetually denied access to resources due to prioritization or scheduling policies.
• Deadlock: Two or more threads are stuck, waiting for each other to release resources, causing a standstill.

What is a detached thread?

A detached thread is one that operates separately from other threads; after it completes its execution, its resources are immediately returned to the system. To detach a thread in POSIX, use pthread_detach().

What is a joinable thread?

A joinable thread is one that can be joined by another thread to make sure it has finished executing or to retrieve its exit state. pthread_join() is used to join POSIX threads.

How does a thread yield execution?

To make room for other threads to run, a thread may choose to freely cede execution. This is accomplished in the majority of systems by employing a function such as yield() or sched_yield() in POSIX.

How are threads used in real-time operating systems (RTOS)?

In RTOS:

• Threads are prioritized based on strict timing constraints.
• Preemptive scheduling ensures high-priority threads meet deadlines.
• Threads are lightweight to minimize latency.

What is a reader-writer lock?

A reader-writer lock is a synchronization primitive that allows:

• Multiple threads to read concurrently.
• Only one thread to write, with no readers allowed during writing.

What are some common thread libraries?

• POSIX Threads (pthreads): Common on Unix-like systems.
• Java Threads: Provided by the Java runtime environment.
• Boost.Thread: C++ library for threading.
• Threading Building Blocks (TBB): Intel’s library for C++.
• Win32 Threads: Windows-specific threading API.

What is a zombie thread?

When a thread ends without its parent thread collecting its exit status, it’s known as a zombie thread. You can either join the thread or detach it to fix this issue.

What are thread barriers, and how are they used?

When a thread ends without its parent thread collecting its exit status, it’s known as a zombie thread. You can either join the thread or detach it to fix this issue.