Re: [B2-devel] Darwin port

[Michael S. <msl...@co...>]

On Jan 18, 2004, at 12:27 PM, Gwenole Beauchesne wrote:

> As you can see, video performance is crappy. Probably that using the 
> Mach exception filters will help a little instead of going through 
> signal handlers with full register state save. Does any Mach expert 
> know how to add exception filters for SIGUSR2/SIGILL things too?

I suppose I am the Mach expert on this mailing list.

I have not looked at the SS code but maybe the concepts are similar to 
B2. Yes signals are crufty and slow on Darwin. What is more of a 
problem is that how the register state is saved is different from 
version to version.

I do not know what you mean exactly "exception filters" in this 
context. It looks to me like you want to to be able to run some code 
whenever you encounter a bad memory access (for vosf), illegal 
instruction (probably for emulation purposes), and some sort of 
communication (the SIGUSR2, BTW what is that for). This is relatively 
straight forward. The first two would be handled by the exception 
handler, the third by a mach message. The message is usually done with 
MIG but since it looks like you are using C++ and I assume the code is 
organized similarly to B2 it would probably be easier to shoehorn it 
directly in like I did with the B2 code.

Tell me which files to look at specifically and give some details as to 
why you did things certain ways which will not be clear from just 
looking at the code and I will look into it and help you out.

mzs