Extension structure
PHP Manual

Life cycle of an extension

A Zend extension goes through several phases during its lifetime. All of these phases are opportunities for the developer to perform various initialization, termination, or informational functions. The Zend API allows for hooks into five separate phases of an extension's existence, apart from calls by PHP functions.

Loading, unloading, and requests

As the Zend engine runs, it processes one or more "requests" from its client. In the traditional CGI implementation, this corresponds to one execution of a process. However, many other implementations, most notably the Apache module, can map many requests onto a single PHP process. A Zend extension may thus see many requests in its lifetime.

Overview


Extension structure
PHP Manual