‘volatile’matters

This is NOT NEW but it still worths being emphasized again…

In my current render engine I have a bool variable that needs to be evaluated like this:

   while(bIsRunning);
 

this piece of code controls the termination of one thread. In debug mode it works fine, but it never ends in release mode – compiler did some harmful optimization that bIsRunning was not evaluated iteratively as code indicates.

Fixing is quite simple:

    volatile bool bIsRunning;
 

Actually this is a common issue in hardware driver development..