[webkit-dev] HasStandardGetOwnPropertySlot

Darin Adler darin at apple.com
Wed Jul 22 18:05:27 PDT 2009


On Jul 22, 2009, at 5:35 PM, Eric Seidel wrote:

> What is HasStandardGetOwnPropertySlot adding?  Is it testable?

It’s an optimization.

If it’s set, then the JavaScript engine won’t even call  
getOwnPropertySlot, saving the overhead of a virtual function call. If  
it’s not set, then the engine will call the virtual function.

If you forget to set it, the only test that you can do is a  
performance test; it will be too slow. If you set and should not, then  
you can test; getOwnPropertySlot won’t get called since you set the  
flag.

     -- Darin



More information about the webkit-dev mailing list