PHP5 VC9, VC6, thread safe, Non thread safe each version difference
PHP official website (http://windows.php.net/download/) 5.3 Altogether gave four versions, VC9 x86 Non thread safe, VC9 x86 thread safe, VC6 x86 Non thread safe, VC 6 x86 Thread Safe, each version is described below.
I. How to select the VC9 version and the VC6 version of PHP5.3
The VC6 version is compiled with the visual Studio 6 compiler, and if your PHP is built with Apache, you choose the VC6 version.
The VC9 version is compiled with the visual Studio 2008 compiler, and if your PHP is built with IIS, you choose the VC9 version.
Second, how to choose the PHP5.3 thread safe and non thread safe version
In the first place, it is a thread safe to understand the literal meaning that thread security is performed in order to prevent the new requirements from exhausting system resources by starting the CGI execution of new threads. Non thread safe is non-threaded and does not thread (thread) security checks at execution time.
Let's look at two ways of executing PHP: ISAPI and fastcgi.
ISAPI execution mode is used in the form of DLL dynamic library, can be executed after the user request, after processing a user request will not disappear immediately, so the need for thread security check, so as to improve the execution efficiency of the program, so if it is to execute PHP with ISAPI, it is recommended to choose thread Safe version;
The fastcgi execution is performed with a single thread, so there is no need for thread security checks, and the removal of thread safety checks can improve execution efficiency, so if PHP is executed in fastcgi, it is recommended to choose the non thread safe version.
The official does not recommend that you apply the non thread safe to the production environment, so we chose the thread safe version of PHP to use.