FreeFEM stalls after some time (probably) due to some exception

General Discussion
1

Hi everyone,

I have encountered a strange issue which I have troubles of finding solution for. I am solving a coupled Cahn-Hilliard/Navier-Stokes system and stepping over time. The strange thing is that for a while the solver is happily working forward, but at some point it stalls. By increasing verbosity variable to 10000000 I have noticed that at the end I get the following messages:

– Solve :
min -2.114 max 2.239
StackOfPtr2Free: clean 0x55f3c8693240
0x55f3c82328b0=newstring((char*) NS done )
NS done 0x55f3c82328b0freestring( NS done )
StackOfPtr2Free: clean 0x55f3c8698b80
catch E_exception 4 0
eval vectorOfInst 0 0
StackOfPtr2Free: clean 0x55f3c82367d0
StackOfPtr2Free: clean 0x55f3c8698b80
catch E_exception 4 0
eval vectorOfInst 0 0

And the last 4 lines seem to repeat indefinitely without any results.

Does anyone have any idea of what might be wrong? Or maybe have any additional suggestion of how to debug the code. I have been following the numerical solution, which seem to behave nicely.

My FreeFEM version:
FreeFem++ - version 4.6 (Tue 16 Jun 2020 06:53:31 AM CEST - git v4.6-113-g243cbb52) 64bits
compiled on Debian linux.

Best,
Ugis Lacis
KTH Engineering Mechanics

2

Can he see the code, because the line
eval vectorOfInst 0 0
is strange because the vectorOfInst is empty.
F. Hecht

3

Hi,

The code is a bit lengthy, but you are welcome to have a look (I sent you an e-mail, the forum did not allow me to attach the file). Let me know if you see anything strange there.

Best,
Ugis

4

Hi again,

Just to close the topic, Frederic helped me to find the issue, using “showCPU = 1” allowed to identify a loop my code got stuck into. So issue is fixed.

Best,
Ugis