Is a bad practice to declare static variables into functions/member functions?

Question

Recently a fellow worker showed to me a code like this:

void SomeClass::function()
{
    static bool init = false;

    if (!init)
    {
        // hundreds          


        

Answer 1

Think multi-threading. This type of code is problematic when function() can be called concurrently by multiple threads. Without locking, you're open to race conditions; with locking, concurrency can suffer for no real gain.