[crawshaw]

First a point of curiosity, have you seen a linux 1:1 system with blocking I/O scaled to millions of active threads? I have only ever seen it with epoll. My working assumption has been that the kernel blocking calls won't scale, but I have not tested that.

Second, almost all the event-driven C++ servers I have seen are written that way not for performance, but for scaling and latency. There is usually plenty of extra CPU and RAM, only a tiny fraction really bump up against resource limits. (A typical case of the vast majority of code not being performance sensitive.)

Otherwise, I agree with your points in this comment. Especially the broader point that there's no novel component of Go. Go is about combining well-known things together.

However, it seems to me that Go still cuts through the "threads vs. events" argument in a way nothing else does. I can write code in a blocking style using typical libraries, and have it scale to large numbers of active connections.

On other systems the implementations don't scale or I have to heavily restrict library use based on stack growth, or I am tied to a particular OS. It seems to me the only alternatives to Go's nice blocking code environment require significant compromise or require something to be built.