Question

I’m trying to implement some kind of ‘multiprocessing’ in php for my task. The task is to check the status of every device in our network.

For that i decided to use looped exec and it works. But i don’t know whether it works fine or not:

$command = "php scan_part.php $i > null &";
exec($command);

This calls scan_part.php as many times as i need, but the question is: how can i calculate time needed for all of my scan_part.php‘s to be executed?

Please, help me, i’m stuck!

Answer 1

Use proc_open to launch your script instead of exec. Proc_open lets you wait until a process is done through proc_close, which waits until the termination of the program.

$starttime = microtime(true);
$processes = array();
// stdin, stdout, stderr- take no input, save no output
$descriptors = array(
    0 => array("file", "/dev/null", 'r'),
    1 => array("file", "/dev/null", 'w'),
    2 => array("file", "/dev/null", 'w'));

while ($your_condition)
{
    $command = "php scan_part.php $i"; // no pipe redirection, no background mark
    $processes[] = proc_open($command, $descriptors, $pipes);
}

// proc_close will block until the program terminates or will return immediately
// if the program has already terminated
foreach ($processes as $process)
    proc_close($process);
$endtime = microtime(true);

$delta = $endtime - $starttime;