I recently faced an interview question about the difference between a binary semaphore and a mutex in C. I've been using mutex locks quite a bit in multithreading, but this was the first I'd heard of binary semaphores. The interviewer mentioned that binary semaphores are similar to mutex locks but have some distinct features. Given my background in C++ and C#, along with my degree in computer engineering, I'm curious—how common are binary semaphores actually used in practice?
3 Answers
Binary semaphores are pretty reasonably common, though they're often utilized to implement various multithreading functionalities rather than being used directly. So, it's a fair question in an interview for roles that require low-level programming knowledge.
The main thing to remember about binary semaphores is that any thread can call the function to signal (like up()), while with a mutex, only the thread that locked it can unlock it. This difference is critical! Also, semaphores manage a pool of resources, but mutexes focus on protecting critical sections. So, using each appropriately helps keep your code clean and avoids issues with reentrancy.
Actually, I was confused too! It turns out there are important nuances. Just because they seem similar doesn’t mean they behave the same. It’s good to check the documentation for whatever library you're using, as semantics can vary from one implementation to another!
Related Questions
Set Wordpress Featured Image Using Javascript
How To Fix PHP Random Being The Same
Why no WebP Support with Wordpress
Replace Wordpress Cron With Linux Cron
Customize Yoast Canonical URL Programmatically
[Centos] Delete All Files And Folders That Contain a String