Fork us on GitHub

Map, String Performance & JavaScript Native

The iOS VM is getting faster and we have some updates for the developer guide
Post Image

Map, String Performance & JavaScript Native

We've been spending a lot of times looking at performance for one of our enterprise customers. As part of the investigation he came up with an interesting and very important find... He found that hashMap.get("String") was much slower under the new VM than under the old VM. Its these sort of "simple" finds that help narrow down bigger issues in performance that might impact a lot of things in Codename One, since HashMap is so ubiquitous the implications of improving it can be huge.

One of the advantages of the new VM is in the fact that we now also control the full API including the HashMap API and can rewrite large portions of it natively for full performance advantage. But it seems that a lot of the things that were really affecting performance were in the more "subtle" pieces touched by the String class and get method...

We moved many small bottlenecks into native code e.g. toString(), String.equals(), String.hashCode(), etc...
But one of the bigger performance improvements came from improving the behavior of the finalizer methods which reduces CPU usage and potential stuttering.

JavaScript Native

We've made some updates to the developer guide specifically a lot of details related to the JavaScript section and information on the native interfaces for JavaScript. This is important if you want to access the JavaScript code directly which means you need to regenerate native interfaces for older cn1libs to be compatible. If you don't do that compilation with such libraries can result in a compilation error.

Share this Post:

Posted by Shai Almog

Shai is the co-founder of Codename One. He's been a professional programmer for over 25 years. During that time he has worked with dozens of companies including Sun Microsystems.
For more follow Shai on Twitter & github.