What are the differences between spinlocks and mutexes?

What are the differences between spinlocks and mutexes?

Spinlocks and mutexes are both synchronization primitives used in concurrent programming, but they work differently. Spinlocks keep checking (or 'spinning') until the lock becomes available, which can be efficient for short waits. Mutexes, on the other hand, put the thread to sleep if the lock is not available, which is better for longer waits.

When should I use a spinlock instead of a mutex?

You should use a spinlock when you expect the wait time to be very short, as it avoids the overhead of putting a thread to sleep. However, for longer wait times, a mutex is more efficient because it reduces CPU usage.

Are there any downsides to using spinlocks?

Yes, the main downside of spinlocks is that they can lead to high CPU usage if the lock is held for a long time, as the thread keeps spinning. This can cause performance issues, especially in systems with many threads.

Can you give an example of when to use a mutex?

A mutex is ideal in scenarios where a thread may need to wait for a resource that could be held for an unpredictable amount of time, such as waiting for I/O operations to complete.