Performance of exception handling

[Sean Kelly]

On Apr 26, 2011, at 9:29 AM, Denis Koroskin wrote:

> On Tue, 26 Apr 2011 20:14:05 +0400, Sean Kelly <sean at invisibleduck.org> wrote:
> 
>> Right now, traces are generated on throw. It should be possible to generate them on catch instead. The performance would be the same either way however. It would be nice to generate them lazily but I don't think that's possible.
>> 
>> Sent from my iPhone
>> 
> 
> Interesting enough, it is already done lazily (in toString(), which I believe should also cache result when it's called first time), but it can be improved a bit.

The readable version is generated in toString, but the actual trace occurs on throw.  This pretty much requires a memory allocation to store the trace info, which is one cause for the performance hit.

Originally, I didn't have the tracing enabled by default, but no one seemed to like that.  I could try enabling it only for non-release builds if that would be preferable.