Do mutex in C ++ need to be bound to some object or variable?

I'm a little new to streaming, and I'm trying to understand how it works in C ++ 11. A professor in my class gave us this sample code to demonstrate the use of the mutex:

#include <list> 
#include <mutex> 
#include <algorithm>

std::list<int> some_list; // A data structure accessed by multiple threads
std::mutex some_mutex; // This lock will prevent concurrent access to the shared data structure

void
add_to_list(int new_value) {
    std::lock_guard<std::mutex> guard(some_mutex); // Since I am going to access the shared data struct, acquire the lock
    some_list.push_back(new_value); // Now it is safe to use some_list. RAII automatically releases lock at end of function }
}

bool
list_contains(int value_to_find) {
    std::lock_guard<std::mutex> guard(some_mutex); // Must get lock every time I access some_list return
    std::find (some_list.begin(),some_list.end(),value_to_find) != some_list.end();
}

I think the code is somewhat clear, but I had some specific questions.

• Is there any need to specifically associate a mutex with a list?
• And if not, does this mean that at any time when the mutex is used, all threads stop until the mutex is destroyed? Or is it just a subset of threads; perhaps threads in some thread or otherwise connected to each other?
• , , ? ..
• , ? RAII? RAII ?