Global variables lifetime

I'm developing a new extension and it will be necessary to set and access data from variables sharing them between each request. Normanly this variable just need be declared as global or static. In extensions I read that we can do something like that using ZEND_INIT_MODULE_GLOBALS() and ZEND_DECLARE_MODULE_GLOBALS() macros. How is the variable lifetime ? Precisely the variable should be used at webserver startup and still using it until shutdown without lose any data and this should be done in any webserver and plataform (Apache, IIS etc) ??? Explanations will be very appreciated. Regards, -- Themis Vassiliadis