Re: [Scilab-users] How to list the content of the recursion stack?
Hi,
> from
> --> currentMaxDepth = recursionlimit()
> currentMaxDepth =
> 1000.
Thanks Samuel, I didn't know this function. So I face a problem (a bug?):
Scilab cratches with segfault but without reaching the recursionlimit. Here the
used three functions
function out=test_l(in)
if in==0 then
out=in;
return
end
out=in+test_l(in-1);
endfunction
function out=test_ll(in,acc)
if in<=1
out=acc;
return
end
out=test_ll(in-1,acc+in);
endfunction
function l_test(in)
i=1;
while 1
mprintf("\n%d: ",i)
sleep(.5,"s");
select in
case 1
out=test_l(i);
case 2
out=test_ll(i,1);
end
mprintf("%d\n",out)
i=i+1;
end
endfunction
There is no problem with
> recursionlimit(20)
> l_test(1)
The program stops as expected with the message "Limite de récursion atteinte
(20)" when i=19 and
> recursionlimit(20)
> l_test(2)
stops when i=20 (I was wrong when I talked about tail call in my previous
email!). But, with
> recursionlimit(1000)
> l_test(1)
Scilab cratches at i=41 with segfault and with
> recursionlimit(1000)
> l_test(2)
Scilab cratches at i=140. Is this cratch a know bug? (It's quite far from the
recursion limit!)
(Subsidiary question: while l_test(2) stop 1 iteration after l_test(1) with low
recursion limit, l_test(2) allows around 100 iterations more than l_test(1)
before cratch with recursionlimit(1000)! Where does it comes from?)
--Jean-Yves
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Re: [Scilab-users] How to list the content of the recursion stack?
Hello Jean-Yves, Le 06/05/2021 à 11:13, Jean-Yves Baudais a écrit : .../... test_ll improves a bit test_l because it uses tail call, but the max without seg.fault is far from 1000. Where does this limit of 1000 come from? from --> currentMaxDepth = recursionlimit() currentMaxDepth = 1000. set by default in the user's preferences: https://help.scilab.org/docs/6.1.0/en_US/recursionlimit.html A recursion can be triggered in a involontary way according to a quite indirect and complex path. That was the case i have met. I have fixed it with a lot of spying pause() and disp(). But it's not really a way of working... Samuel ___ users mailing list users@lists.scilab.org http://lists.scilab.org/mailman/listinfo/users
Re: [Scilab-users] How to list the content of the recursion stack?
Hi, > [...] When we get a Recursion limit reached (1000) message [...] I'm not a wizard on programming, not at all, and recursion call it's all the time complex for me to use. Anyway, I tested two different recursions and I'm really far from the "Recursion limit"! Here the examples: function out=test_l(in) if in==0 then out=in; return end out=in+test_l(in-1); endfunction //calling sequence // test_l(n); // max n=41 function out=test_ll(in,acc) if in<=1 out=acc; return end out=test_ll(in-1,acc+in); endfunction //calling sequence //test_ll(n,1); // max n=140 test_ll improves a bit test_l because it uses tail call, but the max without seg.fault is far from 1000. Where does this limit of 1000 come from? -- Jean-Yves ___ users mailing list users@lists.scilab.org http://lists.scilab.org/mailman/listinfo/users
Re: [Scilab-users] How to list the content of the recursion stack?
Hello Samuel, If I remember correctly, this message comes without any information as this is a regular Scilab error and should be trap through debug(). However on the latest Scilab dev build it seems to crash my Scilab. Could you post a bug on that please ? Thanks, Clément -Original Message- From: users On Behalf Of Samuel Gougeon Sent: Tuesday, May 4, 2021 3:01 PM To: International users mailing list for Scilab. Subject: [Scilab-users] How to list the content of the recursion stack? Dear all, When we get a Recursion limit reached (1000) message, does anyone know how to know more about which recursive calls are filling and overflowing the recursion stack? Noticeably, the message does not tell anything about the last instruction that yielded the error. This makes debugging quite hard. Using debug() to follow 1000 nested calls is just not possible. The debug page says "launch execution with stop on error". But then, in debug mode, "e whereami" does not display anything, as in normal mode. Thanks Regards Samuel ___ users mailing list users@lists.scilab.org http://lists.scilab.org/mailman/listinfo/users ___ users mailing list users@lists.scilab.org http://lists.scilab.org/mailman/listinfo/users
