Found my mistake, I forgot to call
mg_transfer.build(dof_handler);
before doing anything with it.
Am Donnerstag, 1. August 2019 09:02:15 UTC+2 schrieb Maxi Miller:
>
> Hei,
> the program crashes in release mode way before it crashes in debug mode.
> The code shown is completely from the deal.II-library, with some added
> std::cout<<-lines. The only code written by myself is in main.cc, but the
> crash happens in the code from the library.
>
>
> Am Donnerstag, 1. August 2019 05:27:21 UTC+2 schrieb Wolfgang Bangerth:
>>
>>
>> Maxi,
>>
>> since your program is crashing in debug mode even before the location
>> where it
>> crashes in release mode, let's just ignore the release mode issue -- if a
>> program doesn't run in debug mode, you should not assume that it does
>> anything
>> reasonable at all in release mode.
>>
>>
>> > When compiling in debug mode, my results vary, and the program behaves
>> > unpredictable, even though I run it in serial mode. In this case it
>> fails
>> > earlier during
>> >
>> > |
>> > std::cout <<"Looped over all levels, performing plain_copy:
>> > "<<perform_plain_copy <<" or renumbered_plain_copy
>> > "<<perform_renumbered_plain_copy <<"\n";
>> > if(perform_plain_copy)
>> > {
>> > // In this case, we can simply copy the local range.
>> > AssertDimension(dst[dst.max_level()].local_size(),src.local_size());
>> > dst[dst.max_level()].copy_locally_owned_data_from(src);
>> > return;
>> > }
>> > elseif(perform_renumbered_plain_copy)
>> > {
>> > // std::cout << "dst_level-size: " <<
>> dst[dst.max_level()].local_size()
>> > << '\n';
>> > // std::cout << "src-size: " << src.local_size() << '\n';
>> > Assert(copy_indices_level_mine.back().empty(),ExcInternalError());
>> > LinearAlgebra::distributed::Vector<Number>&dst_level =
>> > dst[dst.max_level()];
>> > for(std::pair<unsignedint,unsignedint>i :this_copy_indices.back())
>> >
>> dst_level.local_element(i.second)=src.local_element(i.first);
>> > std::cout <<"Renumbered copy done\n";
>> > return;
>> > }
>> > |
>> >
>> > plain_copy is (at some point) equal to 0, resulting in the program
>> choosing
>> > the second option (perform_renumbered_plain_copy), where it crashes
>> with a
>> > segfault while evaluating the loop
>> > |
>> >
>> >
>> > for(std::pair<unsignedint,unsignedint>i :this_copy_indices.back())
>> >
>> dst_level.local_element(i.second)=src.local_element(i.first);
>> > |
>> >
>> > This behaviour is rather random, and changes at different runs even
>> though the
>> > program was not recompiled.
>> >
>> > Why is that happening? Did I forget to initialize something, or is that
>> an
>> > internal bug?
>>
>> Is the code you show somewhere in the library, or in your application
>> code? In
>> those cases where it crashes, is this_copy_indices.size()==0, so that the
>> call
>> to .back() yields nonsense?
>>
>> As to why this happens, and does so only intermittently, I don't know. A
>> common cause is that some earlier piece of code (accidentally) overwrites
>> data. But I can of course only speculate.
>>
>> Best
>> W.
>>
>> --
>> ------------------------------------------------------------------------
>> Wolfgang Bangerth email: bang...@colostate.edu
>> www: http://www.math.colostate.edu/~bangerth/
>>
>>
--
The deal.II project is located at http://www.dealii.org/
For mailing list/forum options, see
https://groups.google.com/d/forum/dealii?hl=en
---
You received this message because you are subscribed to the Google Groups
"deal.II User Group" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to dealii+unsubscr...@googlegroups.com.
To view this discussion on the web visit
https://groups.google.com/d/msgid/dealii/66c52a94-54da-4204-9b0d-17d1e4eaa3b8%40googlegroups.com.
