How to use named pipes in PHP between different functions or even different processes without fork?

Question

I want to write an Ajax web application, a game to be specific. Two web clients have to communicate with each other via the PHP server. My approach to solve this is to use A

Answer 1

Just a short statement, that I actually found a nice solution using named pipes:

public function createPipe_test(){
    posix_mkfifo("testpipe", 0777);
}

public function writePipe_test($value){
    $pipeA = fopen("testpipe",'w');
    $valueString = number_format($value);
    $valueLen = number_format(strlen($valueString));
    fwrite($pipeA, $valueLen);
    fwrite($pipeA, $valueString);
}

public function readPipe_test(){
    $pipeB = fopen("testpipe",'r');
    $valueLen = fread($pipeB, 1);
    return fread($pipeB, $valueLen);
}

I have two processes.

If process 1 calls writePipe_test(), then it waits until process 2 calls readPipe_test() to read the data out of the pipe.

If process 1 calls readPipe_test(), then it waits until process 2 calls writePipe_test() to write something into the pipe.

The trick is 'w' and 'r' instead of 'r+'.