PHP installation files under Windows The difference between thread-safe and non-thread-safe

The first Windows version of PHP3.0.17, released on October 20, 2000, started with a thread-safe version, because unlike the Linux/unix system, which works in a multi-process manner, Windows systems work in a multi-threaded way. It is very slow to run PHP as CGI under IIS, because the CGI pattern is built on a multi-process basis, not multithreaded. In general, we will configure PHP to run in ISAPI way, ISAPI is multi-threaded way, so much faster. There is a problem, however, that many commonly used PHP extensions are developed with Linux/unix's multi-process thinking, which can be faulted when running in ISAPI mode. With a thread-safe version, it's more about a thread than it does on the entire IIS security.

Of course, under IIS, CGI mode is the safest way to run PHP, but CGI mode requires a reload and unload of the entire PHP environment for each HTTP request, and its consumption is enormous. In order to take into account the efficiency and security of PHP under IIS, someone has given the fastcgi solution. FastCGI can allow the PHP process to be reused instead of every new request to re-open a process. FastCGI can also allow several processes to execute simultaneously. This solves the problem that the CGI process pattern consumes too much, and the CGI process pattern does not have the advantage of the thread security problem.

Therefore, if you are using ISAPI to run PHP, you must use the thread safe version, while running PHP in fastcgi mode, there is no need to use thread security, with none thread safe (NTS, non-thread-safe) Version to better improve efficiency.

When I download the PHP installation file, I see two different binaries, non-thread safe (Non thread safe) and thread safe, which are listed on the PHP download page: http://windows.php.net/download/. What does this mean, what's the difference?

This is primarily for Web server, in a Windows environment, if you are using a Web server that is Apchae or the following version of IIS 7, you should choose a thread-safe installation file, and if you use fast-cgi mode, you can choose non-thread-safe because The Web sever itself guarantees thread safety.

Some Web servers handle application requests in a multi-threaded rather than multi-process way, because they involve shared registers and memory, so it's easy to make mistakes, and at this point the program needs to spend some extra time dealing with the data consistency in the register, which guarantees thread safety.
So whether the use of thread safety mainly depends on your Web server PHP request processing method, if it is multithreaded processing, then choose thread-Safe, otherwise choose non-thread-safe, then the fast-cgi way can choose non-thread-safe.

PHP installation files under Windows The difference between thread-safe and non-thread-safe