Category Archives: v8-Natives

NativeScript: Performance from the Trenches

Well my video for Performance from the Trenches, was released today!   This is the talk I gave at the NativeScript Developer Days 2017.


There is a lot of good useful information in this Talk, so enjoy.

Slide Deck: Performance

NativeScript App:

V8-Natives Repo:




Announcing a v8-Natives v0.0.1

What are v8-natives, you might ask?    

Well, they are the mostly undocumented javascript commands that control the v8 engine in Google Chrome, Opera and Joyent Node.js.      Some of the commands are %CollectGarbage(), %GetV8Version(), %GetOptimizationStatus() which ties with my other favorite of %OptimizeFunctionOnNextCall()


What can I do with them?

You can tell the engine to Optimize a routine, un-optimize a routine, never optimize a routine, ask it about internal data structures of an variable/object, and one of the most important items is ask if a routine is optimizable.


Why is this important?

Well, the v8 engine has several compilers built in; the lowest compiler is just a full featured javascript interpreter -- it is fast; but compared to one of the actual compilers it is so slow that molasses moves faster.     Do you want to figure out which of your code can be promoted to the faster compilers?   Do you want to see what code is a bottleneck even though at a glance it actually looks good?


So, which of these routines optimizable?

function sum1(a,b) {
try {
var c=a+b;
} catch (err) {
return -1;
return (c);

function sum2(a,b) {
return, arguments);

function sum3(a,b) {  return  sum(arguments);


Look no further:

Available on isle 15, at the deep discount of totally free; we now have all the tools you need to answer the above questions.    A fully working support library that wraps over 20 of the internal v8 native commands in a simple to use library that will not crash your script no matter if you have the v8 native support turned on or off.  Can be left in your app and deployed; and finally   supports both Node and Browsers.

Simple things like "v8.helpers.testOptimization(sum1);"  would tell you right away if the sum1 can be optimized....   Or v8.collectGarbage() will do a full GC before you run some timings on a performance critical code...   Lots of things to help your inner-performance surface.

You can get it at your local npm repository:  npm install v8-natives or check out the github page @