Excessive exception size cost ...

[Stephan Bergmann]

On 03/27/2012 04:21 PM, Michael Meeks wrote:
> 	Well, we force page them in as we launch LibreOffice, and then we go

Yeah, the pagein hack.  More a testimony that we are doing something 
wrong here -- trying to outsmart the OS instead of fixing it --, than a 
legitimate critique on the exception handling implementation, IMO.

> throwing a handful of random non-exceptional UNO exceptions as we start
> up, so ... not sure :-)

Routinely thrown exceptions indicate design bugs; addressable latest 
with an incompatible LO 4.

> 	Presumably exceptions are fair enough in the UNO-world where exception
> throwing is done mostly for fun - before sfx2 throws all the results
> away in favour of a user-reported, and translated 'General Error'
> wrapper ;-)

That wrapper, more often than not, is a bug rather than a feature.  I 
often wished that exceptions indicating programming or packaging errors 
were left unhandled, leading to easy-to-diagnose unhandled exception 
termination rather than unhelpful LO error boxes.

> Obviously as we use UNO less for core functionality for
> which it is not suited, I suggest we try to avoid using exceptions in
> new code where possible, and try to avoid these highly granular
> exceptions that ripple up from every trivial object allocation / string
> method.

I still do not consider the eh table sizes problematic enough to dismiss 
exceptions as a useful tool.  If you are concerned about object size, 
I'd rather look into things like -Os or generally removing cruft from 
our code base.

Stephan