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> Everything that Go has is already in Java. If you think that, then you need to take a closer look at Go, or Java, or both. In short: Go compiles to native co

by enneff 16y ago

> Everything that Go has is already in Java. If you think that, then you need to take a closer look at Go, or Java, or both. In short: Go compiles to native code (no VM), it has a totally different type system (no classes, not everything is an 'object' like in Java), it permits fine control over memory layout and allocation, it has powerful concurrency primitives (goroutines and channels), and more. Do yourself a favour and look beyond the syntax. It really is very different to Java (or Actionscript?! that's one of the more bizarre comparisons I've heard).

mahmud 16y ago
Java compiles to native code too, when and where it matters. I have looked at Go, as much as the spec would permit me, and what I found was a safe C (or a faster, native Pike) with better concurrency primitives and a dash of higher-order functional goodness. With respect to the finer control over memory allocation; anything one couldn't have done with pools in a GC'ed language? I would love to see how Go handles intricate manual memory layout specification under heavy load, and how sufficiently smart the compiler/runtime is as it tries to guess the best GC strategy :-) I wish you all the best.
- kaib 16y ago
  > With respect to the finer control over memory allocation I think you are understanding it wrong. Go lets you control memory layout, think deciding how things are laid out in a struct. In Java you get indirection and pointers instead. System programming refers mainly to this ability of layout out your data in memory. This makes a world of difference when you are doing high performance code and can control cache locality. Edit, found the link: http://marc.info/?l=git&m=124111702609723 http://marc.info/?l=git&m=124111702609723
- jbooth 16y ago
  Not really. You can use JNI but it's awkward, discouraged, and every JNI call has overhead -- so much overhead that in the Hadoop project, for example, it was faster to implement their own CRC32 than to use the built in one calling zlib.
NickPollard 16y ago
> it permits fine control over memory layout and allocation I had thought that Go had a built-in garbage collector that could not be disabled - is that incorrect? Can you build code that only touches memory with explicit malloc/free (or equivalent) calls? I was very interested in Go when it was announced, but the GC rules it out for my problem domain (high-performance real-time games). If I can do explicit memory management then that makes it interesting again.
- kaib 16y ago
  > Can you build code that only touches memory with explicit malloc/free (or equivalent) calls? Yes you can. There is a package called 'unsafe' that lets you do pointer arithmetics and turn pointers into valid go types. It requires a bit of finesses, pointers from your own memory obviously wont be counted by the gc etc. Plus you need to make sure you only allocate with your own functions. That said, the gc is getting along, it's hard to say when it hits a spot where you can use it for soft realtime applications. We just started doing high performance server coding in Go at Tinkercad and I used it while I still was at Google.

by enneff 16y ago

mahmud 16y ago

Java compiles to native code too, when and where it matters. I have looked at Go, as much as the spec would permit me, and what I found was a safe C (or a faster, native Pike) with better concurrency primitives and a dash of higher-order functional goodness. With respect to the finer control over memory allocation; anything one couldn't have done with pools in a GC'ed language? I would love to see how Go handles intricate manual memory layout specification under heavy load, and how sufficiently smart the compiler/runtime is as it tries to guess the best GC strategy :-) I wish you all the best.

kaib 16y ago
> With respect to the finer control over memory allocation I think you are understanding it wrong. Go lets you control memory layout, think deciding how things are laid out in a struct. In Java you get indirection and pointers instead. System programming refers mainly to this ability of layout out your data in memory. This makes a world of difference when you are doing high performance code and can control cache locality. Edit, found the link: http://marc.info/?l=git&m=124111702609723 http://marc.info/?l=git&m=124111702609723
jbooth 16y ago
Not really. You can use JNI but it's awkward, discouraged, and every JNI call has overhead -- so much overhead that in the Hadoop project, for example, it was faster to implement their own CRC32 than to use the built in one calling zlib.

NickPollard 16y ago

> it permits fine control over memory layout and allocation I had thought that Go had a built-in garbage collector that could not be disabled - is that incorrect? Can you build code that only touches memory with explicit malloc/free (or equivalent) calls? I was very interested in Go when it was announced, but the GC rules it out for my problem domain (high-performance real-time games). If I can do explicit memory management then that makes it interesting again.

kaib 16y ago
> Can you build code that only touches memory with explicit malloc/free (or equivalent) calls? Yes you can. There is a package called 'unsafe' that lets you do pointer arithmetics and turn pointers into valid go types. It requires a bit of finesses, pointers from your own memory obviously wont be counted by the gc etc. Plus you need to make sure you only allocate with your own functions. That said, the gc is getting along, it's hard to say when it hits a spot where you can use it for soft realtime applications. We just started doing high performance server coding in Go at Tinkercad and I used it while I still was at Google.