Try/Catch performance overhead

JavaScript performance comparison

Revision 18 of this test case created

Info

Using try/catch inside of functions that allocate lots of variables introduces significant overhead. See this discussion related to node.js https://groups.google.com/forum/#!topic/nodejs-dev/E-Re9KDDo5w

Interestingly, other js engines don't have this overhead. All test runs have pretty uniform performance. But they are also significantly slower than the v8 control case.

Preparation code

<script>
  var tries = 100000;
  function testA(j) {
    var s = 0;
    for (var i = 0; i < j; i++) s = i;
    for (var i = 0; i < j; i++) s = i;
    for (var i = 0; i < j; i++) s = i;
    for (var i = 0; i < j; i++) s = i;
    return s;
   }
   function testB(j) {
    try {
     var s = 0;
     for (var i = 0; i < j; i++) s = i;
     for (var i = 0; i < j; i++) s = i;
     for (var i = 0; i < j; i++) s = i;
     for (var i = 0; i < j; i++) s = i;
     return s;
    }
    catch (ex) {}
   }

  function test1() {
   
   testA(tries);
  }
 
  function test2() {
 
   testB(tries);
  }
 
  function test3() {
 
   try {
    testA(tries);
   }
   catch (ex) {}
  }
</script>

Test runner

Warning! For accurate results, please disable Firebug before running the tests. (Why?)

Java applet disabled.

Testing in unknown unknown
Test Ops/sec
control - no try/catch
test1();
pending…
try/catch inside function
test2();
pending…
try/catch outside function
test3();
pending…

Compare results of other browsers

Revisions

You can edit these tests or add even more tests to this page by appending /edit to the URL. Here’s a list of current revisions for this page:

0 comments

Add a comment