Date: 09/18/05 (Java Web)    Keywords: php

In PHP you can register a function to be executed when script processing is complete using register_shutdown_function. In PHP 4.0.6 and below the registered shutdown functions are called after the request has been completed, including sending any output buffers. So a long running function can execute without affecting user experience. However in PHP 4.1 and above the [...]

Source: http://blog.taragana.com/index.php/archive/post-processing-limitations-in-php/