6.2.5 Synchronization (Semaphores, Mutexes)

(Difficulty Note: This is very advanced. Focus on the problem, not the specific solutions.)

When multiple "workers" (threads or processes) are trying to use the same "tool" or "resource" (like updating a single number in memory, or using the printer) at the same time, things can get messy. Imagine two people trying to write on the same whiteboard at the exact same moment – their writing would overlap and be unreadable!

Synchronization is how the OS makes sure that when multiple processes or threads need to use a shared resource, they do so in an organized way, one at a time, to avoid corruption or errors.

Tools like Semaphores and Mutexes are like traffic lights or locks that the OS uses.

A Mutex (short for Mutual Exclusion) is like a "key" to a room. Only one process can hold the key at a time, meaning only one process can be "in the room" (using the shared resource) at any moment.
A Semaphore is like a counter. It can allow a certain number of processes to use a resource at once, or signal when a resource is available.

These tools are crucial for making sure complex programs that do many things at once work correctly and reliably.

Bibliography:

Process Synchronization. (n.d.). GeeksforGeeks. Retrieved July 10, 2025, from https://www.geeksforgeeks.org/process-synchronization/
Mutex and Semaphore. (2023, July 31). Medium. Retrieved July 10, 2025, from https://medium.com/@irfanhaydararman/mutex-and-semaphore-e223321ddd7c