Limit execution time of an function or command PHP

Solution 1:

set_time_limit() does run globally, but it can be reset locally.

Set the number of seconds a script is allowed to run. If this is reached, the script returns a fatal error. The default limit is 30 seconds or, if it exists, the max_execution_time value defined in the php.ini.

When called, set_time_limit() restarts the timeout counter from zero. In other words, if the timeout is the default 30 seconds, and 25 seconds into script execution a call such as set_time_limit(20) is made, the script will run for a total of 45 seconds before timing out.

I've not tested it, but you may be able to set it locally, resetting when you leave the

<?php
set_time_limit(0);  // global setting

function doStuff()
{
    set_time_limit(10);   // limit this function
    //  stuff
    set_time_limit(10);   // give ourselves another 10 seconds if we want
    //  stuff
    set_time_limit(0);    // the rest of the file can run forever
}

// ....
sleep(900);
// ....
doStuff();  // only has 10 secs to run
// ....
sleep(900);
// ....

set_time_limit() ... Any time spent on activity that happens outside the execution of the script such as system calls using system(), stream operations, database queries, etc. is not included when determining the maximum time that the script has been running. This is not true on Windows where the measured time is real.

Solution 2:

You would need to code that yourself if you want function1 to return when the time limit is up.

function doStuff($seconds)
{
    $finish=time()+$seconds;

    $done=false;
    $timeout=false;

    while (!$done && !$timeout)
    {
        //do stuff here, set $done to true if you complete

        //out of time?
        $timeout=time() >= $finish;

    }

    return $done; //let caller know if we completed
}

Of course, the "stuff" that you do needs to be iterative so that you can keep checking on your elapsed time and quit if necessary.

If you want timeout execution of an arbitrary function and have control returned to you, that is not supported. If you really need to do this, engineer it as a separate process. Then you can close the process if it seems to be taking too long.