PHP non-thread safe vs thread safe

Detail Non thread safe thread safe
Thread single thread is used multi-processing
Env CGI binary, command line env need multiple PHP threads
Web server Nginx/Lighttpd Apache MPM

What are they

Since with mod_php, PHP gets loaded right into Apache, if Apache is going to handle concurrency using its Worker MPM (that is, using Threads) then PHP must be able to operate within this same multi-threaded environment – meaning, PHP has to be thread-safe to be able to play ball correctly with Apache! 1