How to define threadsafe?

Question

Threadsafe is a term that is thrown around documentation, however there is seldom an explanation of what it means, especially in a language that is understandab

Answer 1

Multithreading leads to non-deterministic execution - You don't know exactly when a certain piece of parallel code is run.

Given that, this wonderful multithreading tutorial defines thread safety like this:

Thread-safe code is code which has no indeterminacy in the face of any multithreading scenario. Thread-safety is achieved primarily with locking, and by reducing the possibilities for interaction between threads.

This means no matter how the threads are run in particular, the behaviour is always well-defined (and therefore free from race conditions).