Do php 5 try catches affect performance when no exception is caught?

Question

Someone extremely smart at work told me try catches which don't throw will affect performance on a site with millions of users. based on the unit test posted showing equal performance, I'm wondering if this is related to an os level and/or web server specific situation. For instance, web server's implementation of asynchronous work occurs on child processes instead of threads.

Anyone know?

What I'd like to see is an output of a php profiler showing actual cpu time used.

jmucchiello's comment on http://stackoverflow.com/questions/104329/performance-of-try-catch-in-php is interesting, but doesn't measure cpu time used.

Thanks, David

Answer 1

I ran a very small and unscientific test and found there to be roughly no difference between having a catch that never gets called or having it outside a try catch statement. I ran each of these two scripts 5 times each through my profiler and averaged the total times.

Results

• With Try/Catch statement: 1.34 seconds
• Without Try/Catch statement: 1.3 seconds

The Code

Try/Catch

<?php
foreach(range(1,200000) as $i) {
    try {
         if ($i % 5 == 0 && $i % 3 == 0)    echo "fizzbuzz";
         elseif ($i % 5 == 0)           echo "fizz";
         elseif ($i % 3 == 0)           echo "buzz";
         else                   echo $i;
     } catch (Exception $e) {
         echo sin($i) * cos($i * pi());
     }
}

?>

No Try/Catch

<?php
foreach(range(1,200000) as $i) {
     if ($i % 5 == 0 && $i % 3 == 0)    echo "fizzbuzz";
     elseif ($i % 5 == 0)           echo "fizz";
     elseif ($i % 3 == 0)           echo "buzz";
     else                   echo $i;
}

?>