(PHP 4 >= 4.0.5, PHP 5, PHP 7, PHP 8)
apache_child_terminate — 在本次请求结束后终止 apache 子进程
apache_child_terminate() 将把运行当前 PHP 请求的 Apache 子进程注册为终止状态，一旦结束 PHP 代码的运行此进程将终止。可以用在占用大量内存的脚本后面来终止该进程，因为通常内存只在内部释放而不会还给操作系统。
在 Apache 和 FastCGI 网页服务器中运行。
此函数没有参数。
没有返回值。
注意: 此函数未在 Windows 平台下实现。
I found out a solution for Apache 2. However this works only without threads and only on POSIX compatible OS systems (e.g. Linux, OpenSolaris...).
<?php
// Terminate Apache 2 child process after request has been
// done by sending a SIGWINCH POSIX signal (28).
function kill_on_exit() {
posix_kill( getmypid(), 28 );
}
register_shutdown_function( 'kill_on_exit' );
?>On FastCGI SAPIs this doesn't kill the process, it just makes the fastcgi handler fully recycle PHP at the end of the script rather than just recycling the request state. This includes php-cgi.Apache child processes are greedy. If they get bloated by a PHP application that requires a lot of memory, they stay that way. The memory is never given back to the OS until that child dies.
You could use MaxRequestsPerChild in Apache to kill all child processes automatically after a certain number of connections. Or you can use apache_child_terminate to kill the child after your memory intensive functions.
Note: apache_child_terminate is not available in Apache 2.0 handler.In response to sam at liddicott dot com:
it isin't so simple! You should never kill an apache process because it is automatically freed when apache need!
And, if you use apache worker or thread based mpm you risk to kill the entire process!
result: DO NOT USE THIS FUNCTION!this code will add apache_child_terminate() function if it is not already present.
if (!function_exists("apache_child_terminate")){
function apache_child_terminate(){
register_shutdown_function("killonexit");
}
function killonexit(){
@exec("kill ".getmypid());
}
}