Flushing libgfortran from C

[Jerry DeLisle]

On 03/03/2011 12:37 AM, Yuri Gribov wrote:
> Hi all,
>
> Perhaps this is a well known issue but I could not find suitable
> solution on the web. Here is my problem.
>
> Some of you may know about the Co-array Fortran 2.0 project in Rice
> university. CAF translates it's input files to an ordinary Fortran and
> then uses gfortran (4.4 in my case) to compile them (libgfortran is
> linked as shared library). CAF's runtime system is written in C so
> main() looks like:
>
> int main() {
>    CAF_INIT();
>    MAIN__();
>    CAF_EXIT();
> }
>
> The problem is that CAF_EXIT does _exit() internally (don't ask me
> why) which bypasses all registered exit handlers including
> libgfortran's destructor (cleanup in runtime/main.c). This seems to
> cause problems with Fortran IO: I tried all sorts of fflushes, fsyncs
> and sleeps in CAF_EXIT but neither of them makes libgfortran print
> it's internal buffers. This results in empty stdout on most of the CAF
> programs on my platform (even simple Hello world fails to print).
>
> If I change _exit to exit or gfortran to ifort everything prints fine.
>
> Does this sound reasonable? Is this a known IO problem/feature?
>
> Is there any way to workaround this i.e. to ask libgfortran to flush
> (from C program)? I know about `call flush()' and environment
> variables but these really solve different problems and would not be
> useful in CAF's case.

Are the Fortran side files being explicitly closed or are you counting on 
implicitly closing on exit?

 From your description, it seems the C code is existing before the Fortran code.

Jerry