How can I use something like std::vector?

Question

I have a large, but potentially varying, number of objects which are concurrently written into. I want to protect that access with mutexes. To that end, I thought I use a

Answer 1

I suggest using a fixed mutex pool. Keep a fixed array of std::mutex and select which one to lock based on the address of the object like you might do with a hash table.

std::array mutexes;

std::mutex &m = mutexes[hashof(objectPtr) % mutexes.size()];

m.lock();

The hashof function could be something simple that shifts the pointer value over a few bits. This way you only have to initialize the mutexes once and you avoid the copy of resizing the vector.