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[Public WebGL] WebGL Shader Validation



On Thu, Jun 17, 2010 at 7:49 PM, Steve Baker <steve@sjbaker.org> wrote:
There is a rather fundamental problem with detecting infinite loops
either by code inspection or simulation. Alan Turing had a few words to
say about that:

       http://en.wikipedia.org/wiki/Halting_problem

It is a mathematical certainty that no "verifier" can possibly detect
whether an arbitary program will eventually halt.


And here I was thinking some of this stuff we learned in our CS classes would never be used.

My two cents: any driver that doesn't have a watchdog timer such as that is sort of like running a cooperative multitasking OS except the programs can be written by anyone on the internet. Anyone at all. Expect terrible things.

I agree with Steve, limiting the shaders' flexibility due to an issue that can be solved by "better drivers" is the wrong way to handle the issue. If the halting problem were really a problem for a multitasking OS, then we'd be in deep trouble. I'd like to see a configurable timer for the web browser, but I think the interval of the timer will largely be OS-specific, and not all that configurable. For example, Windows Vista/7 use a registry key (global), and that doesn't seem like something an unprivileged app will/should be able to change.

Patrick Baggett