fork.php

function run_function($name, $params) {
	// Actually run the function in question
}

while(true) {
	// Wait for a connection and extract the function to start

	if (function_exists('pcntl_fork')) {
		$pid = pcntl_fork();
		if ($pid == -1) {
			die('could not fork a child -- something is wrong');
		} else if ($pid) {
			// we are the parent. Nothing to do here, so just wrap back around the loop		
		} else {
			// we are the child. Run the function
			run_function($name, $params);
		} 
	} else {
		// We don't have pcntl, so just run in process
		run_function($name, $params);
	}
}