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Reminder: This is part of the conversation resulting from the request that the cach statement
used by lua when compiled as C++ be changed to avoid catching the main application's exceptions.

Continue below:

"Sam Roberts" <sroberts@bycast.com> wrote in message 20060801170134.GE18462@pebble">news:20060801170134.GE18462@pebble...
On Tue, Aug 01, 2006 at 12:51:48PM -0400, Joe Smith wrote: 
"Joe Smith" <unknown_kev_cat@hotmail.com> wrote in message
news:eagvcd$m9n$1@sea.gmane.org...
>
>"Mark Hamburg" <mhamburg@adobe.com> wrote in message
>news:C0F144E9.48687%mhamburg@adobe.com...
>>If you do that, I think it will probably leave the Lua state messed up.
>>
>>Mark
>
>Concurred. However, that is for the end user to deal with. Enigma,
>the project in which I noticed that catch statement has reasons to do
>this, and in all such cases will discard the lua state, automatically
>assuming it is corrupted beyond repair.

Is it possible to be corrupted badly enough that it can't be closed? 


Remember that the use case here is:
C++ program (this has the exception handler)
Lua script (executed by c++ program)
C/C++ function (called by lua script) throws exception.

Lua will probably be left in the state it was in, which is to say.
a script in running, waiting for a C/c++ function to return.
Needless to say that function will not be returning. IT should be possible
to clean up the lua state, but it easier just to close it, open a new one, and re-initalize.


It is a much bigger problem if the exception gets caught by lua. The C++ program would
be left in a mostly consistant state, but memory leaks are nearly certain to result.





And aren't memory leaks also possible?


Closing a lua state should cause Lua to free any memory in use by that state. So I would be much more worried about
the longjmp lua uses for internal errors. Longjmp is easy to use in a way that causes memory leaks. All too easy.

And there is a possibility that c++ app may leak memory, but that is the application's problem, and is always possible when using exceptions.