Re: Regarding exceptions

[muppet <scott asofyet org>]

On Sep 4, 2004, at 11:07 AM, Andy Wingo wrote:

> How does it sound?

it sounds great, exception safety would be a wonderful feature for GLib 
and friends to have.

forgive me if i throw some fastballs at you:

c++ code that uses exceptions typically must follow a convention of 
allocating objects on the stack, because unwinding the stack can't 
clean up objects allocated on the heap (without help from catch() 
blocks).  garbage-collected languages like perl, python, java, c#, etc 
can get around this restriction primarily because of the use of garbage 
collection (although i imagine it's still possible to get leaks if you 
have self-referential data structures and the like).

with that in mind, the API you propose will have to be public, and will 
have to be used pervasively throughout GLib and GTK+, since nearly 
everything those libraries do involves putting stuff on the heap.

how much of a performance and code size hit do you guess this will 
involve?  (i know lots of C++ projects that explicitly avoid exceptions 
because of such penalties.)  how much of the exception safety could be 
made magical and automatic?  (it's an added layer of complexity that 
many app developers may skip.)

if you don't mind the leaks, could it be possible simply to re-work the 
innards of signal emission to fail nicely when the cleanup blocks are 
skipped?

--
Holy crap, dude, we have kids!
	-- Elysse, six days after giving birth to twins