On Friday, 7 February 2014 at 19:54:14 UTC, Jonathan M Davis
wrote:
They're not as performance critical as normal code, but their
speed still very much matters.
Well, it is at least more difficult to write reliable code when
you have to try to avoid them. Still for a webservice you should
probably not have to deal with more than 1000 per second on
average, assume 1Ghz, then that is like 1.000.000 cycles of
running code per stack unwinding.
If you sacrifice 10% of that for exception handling that means
you have 100.000 cycles to unwind the stack. If the unwound stack
is 5 frames deep you have 20.000 cycles per stack frame. If that
is not possible something should be done with the Release-version
of the runtime.
For a webserver you could of course tie the request handler
directly to the request object and instantiate different ones for
each request type then have all "unwinding" in the object itself.
Quirky, but workable.
