What are the primitives for synchronization?

The primitives for synchronization include mutexes, semaphores, condition variables, and barriers. Mutexes provide exclusive access to shared resources, ensuring that only one thread can access the resource at a time. Semaphores allow control over access to a limited number of instances of a resource, while condition variables enable threads to wait for certain conditions to be met before proceeding. Barriers synchronize multiple threads at a specific point, ensuring they all reach that point before any are allowed to continue.