Yeah, a brief look at his buffering code raised alarms all over the place for me. The use of dynamic memory allocation; the use of strlen to find out if the current buffer is empty - seriously? memset()'ing the entire buffer instead of bothering to zero out just the by after the end of the recv(). That's ignoring various bugs and other stuff.

I haven't looked at the rest of the code, but if it's anything like the buffering code this is nothing like what you'd expect to see in a decent C implementation.

It's fairy enough to demonstrate that the Go version makes it easy to write decent performing code, but the C version is atrocious (though to his credit it does at least buffer - I've seen so much C networking code that murders performance by doing small read()'s that I want to cry, including for the longest time the MySQL client library).

Of course part of his criticism is also down to not bothering to look for the plethora of C networking libraries that does this and does it well.