Hi Oguz, You can get better stack traces by compiling in debug mode (both Cap'n Proto itself, and your project). You should then see a symbolic trace instead of a bunch of addresses.
This is a strange error, though. Looking at the code for ReaderArena::tryGetSegment(), the insert() call only happens after a find() call looking for the same key has failed. How could the inserted row already exist, then? Moreover, the whole sequence is performed under a mutex lock, seemingly ruling out any race conditions. I'm not sure what to say here. If you can come up with a self-contained test case that reproduces the issue, I'd be happy to debug. -Kenton On Tue, Oct 1, 2019 at 9:10 AM <[email protected]> wrote: > Thanks for this amazing software. > > We are using v0.7.0. I would like to ask help debugging the following > exception which we rarely but consistently get: > > terminate called after throwing an instance of 'kj::ExceptionImpl' > what(): kj/table.c++:44: failed: inserted row already exists in table > stack: 7f6f7f0697 7f6f7f1ee3 7f6f802623 7f6f5dc9ab 7f6f5b4823 7f77fdd5bf > 557c6f2957 557c63df2b 7f78a30e13 7f78b0f087 > > Our backtrace shows that we were trying to read from a proto, then the > following two functions in capnp were called: > > - kj::Table<kj::HashMap<unsigned int, kj::Own<capnp::_::SegmentReader> > >::Entry, kj::HashIndex<kj::HashMap<unsigned int, > kj::Own<capnp::_::SegmentReader> >::Callbacks> > >::insert(kj::HashMap<unsigned int, kj::Own<capnp::_::SegmentReader> > >::Entry&&) > - capnp::_::ReaderArena::tryGetSegment(kj::Id<unsigned int, > capnp::_::Segment>) > > Why would reading from proto trigger an insert call? > > How can I make use of the "stack: 7f6f7f0697 7f6f7f1ee3..." to debug this > further? > > If the way we read proto is OK, can this perhaps be caused by how we > populate the proto contents? Perhaps some missing or corrupt members? > > Thank you very much for help in advance, > Oguz > > -- > You received this message because you are subscribed to the Google Groups > "Cap'n Proto" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/capnproto/d6512e2e-b990-47c6-9892-a252c0c629c3%40googlegroups.com > <https://groups.google.com/d/msgid/capnproto/d6512e2e-b990-47c6-9892-a252c0c629c3%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "Cap'n Proto" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/capnproto/CAJouXQ%3Df2tOJKqL7kMTsdpvDp0j5XY-4qFyD0ogytHMMq%2BTkNA%40mail.gmail.com.
