0000092: Near-endless loops using catch()

ID	Project	Category	View Status	Date Submitted	Last Update

0000092	LDMud 3.3	Runtime	public	2004-07-14 03:05	2012-12-09 01:55

Reporter	menaures	Assigned To	zesstra
Priority	normal	Severity	minor	Reproducibility	always
Status	closed	Resolution	won't fix
Target Version	3.3.721

Summary	0000092: Near-endless loops using catch()
Description	Just happened to notice this... execution continues if there's not enough eval reserve available for catch(). So I just had to try this: ---- 8< ---- while(1) catch(1; reserve get_eval_cost()); ---- 8< ---- Even without the 'reserve get_eval_cost()' add-on the driver hangs for quite some time because UNItopias default reserve is with 64k evals quite big. The driver is busy for quite a long time writing thousands of 'Caught error: Not enough eval time left for catch()' into the debug logs. I'm quite sorry about this coz this behaviour was introduced in 3.3.559 and suggested by me (changelog says so, but I don't remember and can't find any related mail). Quite unsure what to do about the issue though... only see two possibilities right now, either ignore it (mudlib problem, well, since there are also other ways to let the mud hang for a bit) or return to the old behaviour. Need to recall my reasoning for this suggestion, though.
Tags	No tags attached.

~~lars~~ 2004-07-14 06:31 reporter ~0000101	I am leaning towards leaving it this way - using while(1) is always asking for trouble, and as long as the eval-cost limit eventually ends such a loop, there is not much else that can be done. The reasoning for the change (we talked about it April this year) was to make the handling of catch easier: Something like if (msg = catch(...) { write("Error: "+msg+"\n"); } did not handle the 'not enough evals left for catch' situation before the change.

menaures 2004-07-16 08:28 reporter ~0000108	Other possibilities would be - additional eval cost based on elapsed time (suggested by Gnomi) - intelligent catch which raises a real error if there aren't enough evals for catch n times in a row during an execution - make catch cost more evals if there aren't enough evals if there's still a considerable amount of evals left. }:-)

zesstra 2011-02-14 15:18 administrator ~0001980	I tend to close this as WONTFIX, although: we might consider Menaures suggestion to raise a real error in catch(), if there were not enough eval costs for 10 calls to catch() in a row in the same executions thread.

zesstra 2012-12-09 01:55 administrator ~0002174	So it seems we won't fix this.

Date Modified	Username	Field	Change
2004-07-14 03:05	menaures	New Issue
2004-07-14 06:31	~~lars~~	Note Added: 0000101
2004-07-16 08:28	menaures	Note Added: 0000108
2009-01-29 01:32	zesstra	Relationship added	related to 0000603
2011-02-14 15:18	zesstra	Note Added: 0001980
2011-02-14 15:18	zesstra	Status	new => feedback
2011-02-23 22:02	zesstra	Target Version	=> 3.3.721
2012-12-09 01:55	zesstra	Note Added: 0002174
2012-12-09 01:55	zesstra	Status	feedback => closed
2012-12-09 01:55	zesstra	Assigned To	=> zesstra
2012-12-09 01:55	zesstra	Resolution	open => won't fix