Strange behavior when algebraic loop solution misses tolerance

[rruusu]

Description

When algebraic loop solution produces a warning about not reaching the desired tolerance, the simulation may produce unreasonably erroneous results.

This seems to be caused by omitted transfer of values from outputs to inputs after said warning occurs.

Expected behavior

Even if the tolerance is only barely missed, the effects on the overall solution tolerance should be proportionate.

Version and OS

• Version: OMSimulator v2.1.2.post5-gce342b6-mingw-notlm-debug
• OS: Windows 11, 64-bit

[rruusu]

The culprit seems to be this return statement in oms::SystemSC::updateInputs that terminates the loop over all connections, even if the return value indicates just a warning. In this case, the simulation continues with some connections omitted entirely.

[lochel]

Thanks, good catch. Do you have an (preferably minimal) example to trigger this problem?

[rruusu]

This issue is unlikely to be triggered without a fix to #1513. I only ran into it when making changes that incidentally fixed the issue.