A few days ago one of my build machines started to have unexpected test failures during regular integration builds of one of my client’s codebases. My other build machines ran the tests fine and the failures were intermittent and spread over a worryingly large array of tests.
TL;DR
Don’t use CLOCK_REALTIME to measure wait or delay times as it can be changed and the time reported can move unexpectedly; absolute timeouts do not play nicely with this clock.
I have been using a home-grown continuous integration system based on a hacked version of CruiseControl.Net since 2007. Whilst it’s not perfect, it works, and I have quite a bit of custom tooling that builds configurations for it for various client projects and builds of various versions of The Server Framework.
TL;DR
By exporting the configuration of Visual Studio as a vsconfig file you can create a custom installation with specific tools in a stand-alone directory structure that can be referenced by build tools, and you can then link specific revisions of code to specific versions of Visual Studio so that they ‘always build’, even if the installed compiler is incompatible.
I’ve been playing around with the low-level access to the Windows networking stack that is provided by \Device\Afd. This provides a ‘readiness’ interface rather than the ‘completion’ interface provided by traditional IOCP designs. I’ve been meaning to do some comparative performance tests, much in the same way that I did for my investigations of the RIO API, but I’ve been too busy.
Instead, what has happened is that the AFD code has made its way into the version of The Server Framework that I’m using with my Online Game Company client.
I’ve been cleaning up a continuous integration build system for my cloud gaming client’s server system. The codebase is pretty big, and my build system on Windows is pretty rubbish but works… It has been getting slower and slower due to how I build the system, and I wanted to make it faster. Whilst doing this, I ran into a Visual Studio error message that I hadn’t seen before, and it took me a while to work out what was going on…
Last time I looked at way of using \Device\Afd to perform individual socket polling for readiness. This differed from the previous approach to using \Device\Afd, which batched up the sockets and issued a single poll for multiple sockets.
The individual socket polling approach appeals to me as it would appear to scale more easily, and putting together an echo server that supports multiple connections is now much easier. It doesn’t map as well to the way other operating systems do things though, so if that’s your primary goal, then you’re probably better off continuing with the ‘set of sockets’ approach.
Recently, I’be been exploring socket readiness notifications on Windows using the \Device\Afd interface. My initial forays into this were from a Linux epoll direction as the use of the \Device\Afd API provides a similar interface to the epoll API and makes it possible to build something almost the same on Windows which can help when writing cross platform code.
I’d got to the point where I had a simple client and server working nicely and had taken a pause before the next step which was to add support for multiple sockets.
I’ve just had to deal with a situation where Windows 11 Explorer crashes and restarts every time I browse to a particular directory. The directory contained the source to my AFD code and I somehow managed to guess at the cause and fix the offending file…
The problem was that I had some Visual Studio sln files checked in to a git repository and at some point git had changed the line ends from windows \r\n to unix \n.
For a while now I’ve been playing around with the low-level access to the Windows networking stack that is provided by \Device\Afd. Recently I had a comment from a reader, Matt James, who pointed me in the direction of his work over at https://github.com/Emjayen/napi which does a lot more with the \Device\Afd interface than I have. It’s well worth checking out.
This code includes, as reference, a set of NT Native API headers from the Process Hacker project, which in itself is interesting stuff, but Matt’s code goes far beyond my megre investigations and provides enough information to produce a full featured network API that appears to be able to everything you might need through the \Device\Afd interface.
Recently I spent quite a long time debugging a heap corruption bug. When I eventually found the issue, it was such a classic buffer overrun bug that it was actually quite laughable how long it had taken to track it down. It was just SO obvious that I immediately spotted it as soon as I looked at the code. The problem was that it took me so long to actually look at this piece of code.
There’s a lot of noise about how “Joe Biden’s government wants you to move away from using C++”. This is as a result of the US government releasing a report, Back to the building blocks: A path toward secure and measurable software which suggests:
Uncle Sam says "no!"
“Memory safety vulnerabilities are a class of vulnerability affecting how memory can be accessed, written, allocated, or deallocated in unintended ways. Experts have identified a few programming languages that both lack traits associated with memory safety and also have high proliferation across critical systems, such as C and C++.
