Java at 30: Interview with James Gosling

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exabrial ◴[16 May 25 14:51 UTC] No.44006194[source]▶

Java performance isn't the fastest, that's ok, a close 3rd place behind C/CPP ain't bad. And you're still ahead of Go, and 10x or more ahead of Python and Ruby.

Java syntax isn't perfect, but it is consistent, and predictable. And hey, if you're using an Idea or Eclipse (and not notepad, atom, etc), it's just pressing control-space all day and you're fine.

Java memory management seems weird from a Unix Philosophy POV, till you understand whats happening. Again, not perfect, but a good tradeoff.

What do you get for all of these tradeoffs? Speed, memory safety. But with that you still still have dynamic invocation capabilities (making things like interception possible) and hotswap/live redefinition (things that C/CPP cannot do).

Perfect? No, but very practical for the real world use case.

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hintymad ◴[16 May 25 19:43 UTC] No.44009121[source]▶

>>44006194 #

> And hey, if you're using an Idea or Eclipse (and not notepad, atom, etc),

Java's tools are really top notch. Using IntelliJ for Java feels a whole new different world from using IDEs for other languages.

Speaking of Go, does anyone know why Go community is not hot on developing containers for concurrent data structures? I see Mutex this and lock that scattering in Go code, while in Java community the #1 advice on writing concurrency code is to use Java's amazing containers. Sometimes, I do miss the java.util.concurrent and JCTools.

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1. eikenberry ◴[16 May 25 20:37 UTC] No.44009597[source]▶

>>44009121 #

It's a core principle.

    Don't communicate by sharing memory; share memory by communicating.

The overuse of Mutex and Lock are from developers bringing along patterns from other language where they are used to communicating via shared memory. So this aspect of the language just doesn't click as well for many people at first. How long it takes you to get it depends on your experience.

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2. hintymad ◴[16 May 25 20:43 UTC] No.44009657[source]▶

>>44009597 (TP) #

Thanks! What about data structure shared by multiple goroutines? Say, an in-memory cache object? Or do we always have multiple goroutines talk to a dedicated goroutine for the shared value? Would the performance be okay for all use cases? A reason that people use JCTools is that it can easily support hundreds of millions of concurrent reads/writes to its data structures on a 10-year old laptop.

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3. fidotron ◴[16 May 25 21:46 UTC] No.44010054[source]▶

>>44009597 (TP) #

My experience is a shocking amount of the golang community believe channels are a performance problem for whatever they're doing, and they use mutexes in some misguided effort at optimization.

But then I have also encountered Rust people that will look down on Java but had no idea buffered I/O had higher throughput than unbuffered.

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4. eikenberry ◴[16 May 25 23:41 UTC] No.44010784[source]▶

>>44009657 #

For things like cache I generally have 2 goroutines communicating with it. One that directs reads and one that directs writes. Using CSP style you can pass the data (by value) through to the cache (or any other CSP style process) without copying and it performs quite well. I've written several high performance systems in this way with great results.

5. surajrmal ◴[17 May 25 15:16 UTC] No.44014935[source]▶

>>44010054 #

Depending on the situation, channels can absolutely be higher overhead and not worthwhile. Google internally recommends not using them in many situations.

Unbuffered IO is a tradeoff. For certain use cases it does help, because throughput isn't everything. I'm sure Buffered is better in the average use case, but that doesn't mean you would never need unbuffered.

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6. fidotron ◴[17 May 25 16:36 UTC] No.44015439{3}[source]▶

>>44014935 #

> Depending on the situation, channels can absolutely be higher overhead and not worthwhile.

Like streaming arrays one byte at a time through the channel.

Such devs just aren't very good, and hear "Google internally recommends not using them in many situations" but jump to inferring that means all of their situations qualify.

> but that doesn't mean you would never need unbuffered.

Note that this was never claimed.

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7. surajrmal ◴[17 May 25 18:10 UTC] No.44015979{4}[source]▶

>>44015439 #

Channels make the most sense when you need to decouple code. The performance differences rarely are a bit deal. Most of the time it's unnecessary cognitive overhead. People treat both sides as dogma, but the truth is that you need to be think critically when choosing between the two.

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