> I looked at WordPress code and I don't recall seeing any thread stuff being used at all. You misunderstand. You don't need to write threaded code to write

> I looked at WordPress code and I don't recall seeing any thread stuff being used at all. You misunderstand. You don't need to write threaded code to write code that can't be used in a threaded environment. Think about using and accessing global or static variables in a threaded host environment vs a prefork process based environment. PHP devs have adopted the practice of using Apache pre-fork rather than simply fixing their bad code because it hides their mistakes. On top of that, Wordpress being a huge plugin based community, you get tons of poorly written plugins that assume they're running in a single process environment because the authors simply don't know any better. As far as I can tell, most PHP devs seem to think Apache only has a pre-fork mode; they write lengthy articles about how bad Apache is on memory not realizing the only reason it's that bad is because they're using the oldest and most resource hungry worker mpm. They don't seem to be aware Apache has other worker modules like threaded and evented that don't suck down ram like the prefork model does.