I'm so glad to be out of the dark ages of parallelism. Complaining about Go's race detector or exactly which types of logical races Rust can't prevent is such a breath of fresh air compared to all those other single-core languages we're paid to write with that had threading, async, or concurrency bolted-on as an afterthought.
I can only hope Go and Rust continue to improve until the next language generation comes along to surpass them. I honestly can't wait, things improved so much already.
I always run my Go code with `-race`, but I feel more comfortable writing C++ multithreaded code than Go thanks to the thread sanitizer annotations ( `__attribute__((guarded_by(guard)))` and others in the family).
The annotation also help me discover patterns, like when most of the functions of a class have the same annotations, maybe it means that all the functions of the class should have the same annotations.
I really wish an equivalent to those annotations came to Go.
if id == 1 {
counter++;
}
In all honesty, if you “do work” using channels then all your goroutines are “thread safe” as the channel keeps things in order. Also, mutex is working as intended. As you see in your post, -race sees this, it’s good. Now have one goroutine read from a chan, get rid of the mutex, all other goroutines write to the chan, perfection.
You're using Go's race detector wrong if you expect it to actually catch all races. It doesn't, it can't, it's a best effort thing.
The right way to use the go race detector is:
1. Only turn it on in testing. It's too slow to run in prod to be worth it, so only in testing. If your testing does not cover a use-case, tough luck, you won't catch the race until it breaks prod.
2. Have a nightly job that runs unit and integ tests, built with -race, and without caching, and if any races show up there, save the trace and hunt for them. It only works probabilistically for almost all significant real-world code, so you have to keep running it periodically.
3. Accept that you'll have, for any decently sized go project, a chunk of mysterious data-races. The upstream go project has em, most of google's go code has em, you will to. Run your code under a process manager to restart it when it crashes. If your code runs on user's devices, gaslight your users into thinking their ram or processor might be faulty so you don't have to debug races.
4. Rewrite your code in rust, and get something better than the go race detector every time you compile.
The most important of those is 3. If you don't do anything else, do 3 (i.e. run your go code under systemd or k8s with 'restart=always').