Go 1.9 is released (opens in new tab)

In fairness, the phrase he used was "looks like". I don't think his comment was intended to suggest that he'd done rigorous and exhaustive wide-spectrum analysis of compile times and executable size, just that expectations matched the result for his project.

"Programmers Need To Learn Statistics Or I Will Kill Them All"... What an insufferable asshat.

PSA: There is no reason to behave like this and this is an incredible way to alienate a bunch of people. You either offend people directly with the murder implication or they don't take you seriously because you sound like you're throwing such an extended temper tantrum that you managed to write it all in a blog.

So honest question from a non-statistician,

how, concretely, should I go about doing this particular analyzis of compile time for one project ? How many times should I run the build for each of the 2 compilers and what should I do with the result so I could; 1. Draw a conclusion 2. Come up with fair numbers of how they compare ?

I would hope someone could tech this hopefully simple and very concrete thing to the HN crowd and I do hope the answer is not "go learn statistics".

Yes, the other guys are just being pedantic because libc is attempted loaded dynamically (but it is not required—DNS behaviour just may change without it).

> Aren't go programs statically linked?

Not by default. You have to set CGO_ENABLED=0 to statically link libc.

Runtime has changed too... slightly

This is the biggest problem with Go errors and one of my biggest gripes with the language. Exceptions have stacktraces that give you context about where the error originated. Go errors don't have this and it costs me a lot of time debugging things.https://godoc.org/github.com/pkg/errors helps, but it's still more of a pain than it should be.

The implementation makes use of unsafe.Pointer instead.

When "type safe" is mentioned without qualification, it almost always refers to static type safety. This is one of those times. So no, the sync.Map container is not typesafe like a regular map is.

This is incorrect. What you're referring to is "memory safety".

Ah, thanks for the links.

I googled a little bit and found some good info, I guess I had forgotten a little bit of the concepts of mutex fairness/unfairness. I found a very nice explanation on cs.stackexchange:

  "My understanding is that most popular implementations of a mutex (e.g. std::mutex in C++) do not guarantee fairness -- that is, they do not guarantee that in instances of contention, the lock will be acquired by threads in the order that they called lock(). In fact, it is even possible (although hopefully uncommon) that in cases of high contention, some of the threads waiting to acquire the mutex might never acquire it."

Source: https://cs.stackexchange.com/questions/70125/why-are-most-mu...

With that computer science clarification, I think the comment "Mutex is now more fair" and the detailed description "Unfair wait time is now limited to 1ms" makes it a lot clearer.

Great improvement I think! It's one of those things that you don't notice until you have a bug, but it's really nice to never get that bug in the first place. =)

Check the comment here on Mutex faireness: https://go-review.googlesource.com/c/go/+/34310/8/src/sync/m...

> Mutex fairness.

> Mutex can be in 2 modes of operations: normal and starvation.

> In normal mode waiters are queued in FIFO order, but a woken up waiter

> does not own the mutex and competes with new arriving goroutines over

> the ownership. New arriving goroutines have an advantage -- they are

> already running on CPU and there can be lots of them, so a woken up

> waiter has good chances of losing. In such case it is queued at front

> of the wait queue. If a waiter fails to acquire the mutex for more than 1ms,

> it switches mutex to the starvation mode.

> In starvation mode ownership of the mutex is directly handed off from

> the unlocking goroutine to the waiter at the front of the queue.

> New arriving goroutines don't try to acquire the mutex even if it appears

> to be unlocked, and don't try to spin. Instead they queue themselves at

> the tail of the wait queue.

> If a waiter receives ownership of the mutex and sees that either

> (1) it is the last waiter in the queue, or (2) it waited for less than 1 ms,

> it switches mutex back to normal operation mode.

> Normal mode has considerably better performance as a goroutine can acquire

> a mutex several times in a row even if there are blocked waiters.

> Starvation mode is important to prevent pathological cases of tail latency.

Thanks for the link! =)

It was. That summary is a bit of a simplification.

See https://golang.org/doc/go1.9#database/sql

Go 1.9 adds reuse of statement handles created off an ephemeral transaction too. But all the other statement handle cases have cached from day 1.

You could do it manually but it want automatic.

This has been discussed and the discussion derailed very quickly ("Go is a joke, my language has it bigger, blah blah".)

Reality is that the Linux Kernel makes a big confusion between processes and threads in the userspace APIs.

Locking to threads is a solution that works but also sucks and defeats the niceties of Go N:M model. But that's the only way: if you use that broken system calls API you should know better.

Then you have to merge them on every read (after any modification).

Wow great find!

i am dealing with this problem right now. also i have a big problem with deepclone,

I did a big rewrite of a current project, and clearly it was badly designed :(

Standard practice is to use a mutex to guard against concurrent usage.

They're discouraged from complaining about downvoting.

I have been wondering for quite some time how one could implement that. That is, not in the sense of how to code that, but rather how few changes one would have to make to the language to get as many effects as possible in the direction of genericity. There is some inspiration in Lua, Scheme48 and some dialects of ML (functors, I believe?) in the form of "higher-order modules", where the module (would be package in Go?) could have parameters that you'd have to supply when importing it. The things you could obviously supply would be at least constants, functions and types. (One might look at functions as types of computational processes, though, and at function signatures/interfaces as their respective type classes. This perspective could subsume functions as types, and perhaps integers as nullary functions returning an integer.) The question is how to reasonably do the import strings. Good thing about Go is that you already have provisions in the language in the sense that the string can be technically arbitrary. A subset of the reflection interface could additionally be evaluated at compile time to provide for ad-hoc specializations of generic code by writing straightforward code that would be easily eliminated/specialized in a module instantiation (like loops over struct fields etc.)

Easy. You copy the original file twice and put them in two different sub directories, say treef64 and treerune.

Thanks and please check this proposal for go2: https://github.com/golang/go/issues/19814 Thumbs up if you like it.