Yes. The PHP process keeps running but resets completely on every request. The bytecode is cached though, so loading the code shouldn't add much overhead.
PHP can be used for long-running jobs, but it doesn't have very good garbage collection, and has no language-level concurrency and very little asynchronicity.
PHP can be used for long-running jobs, but it doesn't have very good garbage collection, and has no language-level concurrency and very little asynchronicity.