What Is a Mutex in Traditional Programming, and How Does It Relate to a Reentrancy Guard?

A Mutex (Mutual Exclusion) in traditional programming is a synchronization primitive used to prevent multiple threads from simultaneously accessing a shared resource, ensuring that only one thread can execute a critical section of code at a time. A smart contract reentrancy guard is essentially a blockchain-specific implementation of a Mutex.

It uses a boolean state variable to "lock" a function during its execution, preventing any external call from re-entering and executing the same critical code before the first execution is complete.