Earliest zend_eval_string can be called?

Hello, I was wondering how early a zend_eval_string call can be made. Currently it works fine in a PHP_FUNCTION(), but was hoping to put it in a PHP_MINIT() in hopes of it just executing once. It seems PHP_MINIT() is too early, and is causing failures. I came across PHP_GINIT_FUNCTION(), but can't seem to find when its called exactly, but the same situation as PHP_MINIT() seems to be the case, where its too early. In short, I am wondering if there is any place I can put the zend_eval_string() call in hopes of it running just once, so its result could be retained throughout the module execution. Matthew