This week, I learned more about thread synchronization by studying condition variables, semaphores, and common concurrency bugs. These concepts are important in systems programming because they help manage how multiple threads interact with shared data without causing unexpected behavior.

Condition variables stood out to me as a clean way to let threads wait for a specific condition without wasting CPU cycles. Instead of spinning in a loop, a thread can sleep until another thread signals that something has changed. The pthread_cond_wait() function releases the mutex and puts the thread to sleep in one atomic step, which avoids race conditions. It was helpful to see how this is used in scenarios like a parent thread waiting for a child to finish.

Semaphores, on the other hand, are more flexible but can be trickier to work with. A binary semaphore can act like a lock, while a counting semaphore helps manage access to a limited number of resources. The sem_wait() and sem_post() operations provide a simple interface but require careful use to avoid logic errors.

I also learned about common concurrency bugs like atomicity violations and deadlocks. These bugs can be hard to detect but easy to create if synchronization is used incorrectly. The textbook emphasized how important it is to follow patterns like consistent lock ordering to prevent deadlocks.

I think that these lessons helped me understand both the tools and the potential pitfalls of writing multithreaded code and gave me a deeper appreciation for how much thought goes into safe and efficient concurrency.