On 13. 5. 2021, at 17:29, Danny Mayer <ma...@pdmconsulting.net> wrote:
On 5/13/21 9:45 AM, Ondřej Surý wrote:
Hey,
just a follow-up with a recent real life example.
I’ve spent few days hunting a problem on Windows that got introduced by a fix
to outgoing UDP selection code. While having bugs in normal (and this was
really one-liner), it’s abnormal to not have tools for debugging the problem.
Here’s the (incomplete) list of things that would have to be fixed:
1. Automatic crashdump collection in our CI - it should work, but it simply
doesn’t and it also ignores the crashdump collection on the Hyper-V Windows
Server 2016 I am using for building and debugging Windows binaries
If you build the binaries in debug mode does it give you the crashdump
collection? Hard to know without looking at the sources.
2. Automatic crashdump processing - we need full backtrace printed for all the
threads, both in the CI and as a “cookbook” for developers.
What happens on Unix? If this is not out-of-the-box then you have to use the
microsoft tools to do that.
3. The build system rewrite - currently, the build system is this horrible
hybrid of Perl that generated MSVC solution files (ninja-build or cmake would
be sane alternatives)
When the build system was written, around 2001, there were not a lot of
alternatives. I was used to writing TCL but not a lot of people knew that
language. Perl was the popular choice. Today that would need to be worth
revisiting.
4. Improvements like this:
https://gitlab.isc.org/isc-projects/bind9/-/merge_requests/5020 <— the new
networking stack uses libuv where we setup listening on each netmgr thread, on
Windows, we currently limit this to **single thread**. This branch is an attempt
to use WS2 API to make Windows work same as the rest of platforms, but it fails
horribly. It’s beyond our capacity to pursue this any further.
Why is this single-threaded? The Windows code handling the incoming and
outgoing requests was always multithreaded. There was handling within the
Windows code to properly deal with the threads and locking that was necessary.
Currently, working on Windows feels like landing on an alien planet with
failing lifesupport and finding these strange large eggs in the cavern while
having Sigourney Weaver on the team.
Well I had warned that there needed to be someone on the team to properly deal
with the Windows side.
Danny
