What is the difference between mutex and shared_mutex in C++?

What is the difference between mutex and shared_mutex in C++?

In C++, a mutex allows only one thread to access a resource at a time, while a shared_mutex allows multiple threads to read the resource simultaneously but only one to write.

Can you give an example of when to use each?

Use a mutex when you need exclusive access to a resource, like modifying a shared variable. Use a shared_mutex when you have multiple readers and occasional writers, like reading from a cache.

What happens if a thread tries to lock a shared_mutex for writing while others are reading?

If a thread tries to lock a shared_mutex for writing while others are reading, it will block until all readers have released their locks, ensuring data consistency.

Are there performance differences between the two?

Yes, shared_mutex can improve performance in read-heavy scenarios by allowing concurrent reads, while mutex can be faster in write-heavy scenarios due to its simplicity.