[webkit-dev] Limiting slow unload handlers (Re: Back/forward cache for pages with unload handlers)

[Geoffrey Garen]

> The better option, as Adam noted on the bug, is one in which the JS  
> engine itself measures how much work has been performed.  A count of  
> instructions or function calls is a truer measure than the proposed  
> count of time checks, but imposes costs on the JS engine that the V8  
> team have argued are unacceptably high

JavaScriptCore's timeout handling is not just wall-clock based. It  
measures a combination of wall-clock time and actual executed opcodes.  
This mechanism works with no measurable performance cost.

Geoff