mutex

std::mutex: This is the most basic type of mutex in C++. It provides mutual exclusion between threads by allowing only one thread to acquire the lock at a time. If a thread attempts to acquire the lock while it is already held by another thread, the thread will block until the lock is released.

std::recursive_mutex: This is a type of mutex that allows a thread to acquire the lock multiple times without deadlocking. If a thread already holds the lock, it can acquire the lock again without blocking, as long as it releases the lock the same number of times that it acquired it.

std::timed_mutex: This is a type of mutex that allows a thread to wait for a specified period of time to acquire the lock. If the lock is not available within the specified time period, the thread will return an error.

std::recursive_timed_mutex: This is a combination of std::recursive_mutex and std::timed_mutex. It allows a thread to acquire the lock multiple times without deadlocking, and also allows a thread to wait for a specified period of time to acquire the lock.

std::shared_mutex: This is a type of mutex that allows multiple threads to read from a shared resource simultaneously, but only one thread to write to the resource at a time. This can improve performance in situations where multiple threads need to read from a shared resource, but only one thread needs to write to it.

std::shared_timed_mutex: This is a combination of std::shared_mutex and std::timed_mutex. It allows multiple threads to read from a shared resource simultaneously, but only one thread to write to the resource at a time, and also allows threads to wait for a specified period of time to acquire the lock.