PHP version analysis

PHP version resolution PHP has several different versions available for download. That is, VC6 X86 and VC9 X86.

First:
What is VC6?
VC6 is compiled by the legacy Visual Studio 6 compiler.
What is VC9?
VC9 is the Visual Studio 2008 compiler, which is compiled by Microsoft VS editor.

So how do we choose which PHP version to download?
If you are using Apache + PHP in windows, select VC6;
If you are using IIS + PHP in windows, select VC9;

In addition, the version selection of Non-Thread Safe and Thread Safe should also be confusing to everyone,
First, let's take it literally: None-Thread Safe means Thread security, while Thread Safe means Thread security, during execution, the Thread security check is performed to prevent the CGI execution mode of the new Thread from consuming system resources when new requests exist.

Let's take a look at the loading method of php. CGI won't be mentioned. it's too different... Let's look at the ISAPI and FastCGI loading methods. It is inevitable that ISAPI is involved in Linux. here we will also mention that the Linux-based operating system adopts multi-process working methods, windows operating systems that we are familiar with use multithreading. Multi-process and multi-thread are different. ISAPI is used to load php in multiple threads, but many common extensions of php are developed in the way of multi-process work in Linux, so these extensions are in ISAPI, A problem occurs...

Loading php with FastCGI allows the php-cgi process to be reused, instead of re-uninstalled and re-loaded every time like CGI, resulting in a heavy waste of resources. FastCGI can allow several processes to execute at the same time, which solves the problem of high CGI consumption or compatibility between ISAPI and php, and can improve stability to load php. FastCGI executes operations in a single thread, so it does not need to perform thread security checks, saving the thread security check but improving the execution efficiency. Therefore, if FastCGI (whether it is an IIS server, or Nginx server) to load php, we recommend that you use None-Thread Safe version of php.
We do not recommend that you use Non-Thread Safe in the production environment. Therefore, we use PHP of Thread Safe.