Just in case I need to do any locking in my new project... I remember
this older work... Take notice of the raii based locker object in:

https://groups.google.com/g/comp.lang.c++/c/sV4WC_cBb9Q/m/SkSqpSxGCAAJ

locker is meant to be on a per-thread basis. The view into a threads
goal of atomic, deadlock free, wrt its locked objects... Is this crap
wrt trying to show how raii can help, wrt the locker object?

____________
This code allows a thread to dynamically lock multiple addresses in a
totally atomic fashion, and free of deadlock. It is based on hashing
pointers into a table of locks. A thread can create a little array of
hashed pointers, sort them, remove duplicates, then take all of the
locks in the table. The sorting and uniqueness factor prevents deadlock.
_________________
// pseudo-code

mtx_table lock_table;

// some vars
int a = 3;
short b = 6;
double x = 1.234;

// a thread
{ locker locks(lock_table); // our hashed locks
locks.push(&a);
locks.push(&x);
locks.push(&b);

locks.lock();
// a, x, and b are all locked!
locks.unlock();
} _________________

Well, locks.lock() and locks.unlock() can be automated via raii here...
locker is nice...