5 ms·

For my needs, jruby will never suffice as java isn't going to be installed on the servers I'm on. Nor to be honest would I want it, and JNI for c extensions is

by mitchty 15y ago

For my needs, jruby will never suffice as java isn't going to be installed on the servers I'm on. Nor to be honest would I want it, and JNI for c extensions is also a nonstarter. We have puppet at work for server deploys, and well, jruby may suffice for web/app server deploys that just run rails. But not all ruby users actually give a rats about rails (that's me, don't use it at all at work), nor do we have a need for java interop. Basically I'm in the exact opposite of your vantage. I need c bindings for a few gems I made that need c ffi bindings, I don't need/care/use any java interop, and personally, I'd rather not have the jvm running on any of my servers. I look at rubinius as the eventual YARV for the compiled version as YARV was to MRI, not as an academic project. But I admit, I seem to be a ruby outlier ever since rails has been around.

ssmoot 15y ago
I don't use Rails. I see the JVM as a tool that gives me access to code I might find useful, and web-servers that are (IMO) 1000X superior to anything available to MRI. That and much better performance than REE anyways. If you need C-extensions, well, there you go. Rubinius as a better MRI I totally get/agree with. I think we agree on that as a good reason for the season for Rubinius. It'd just be nice for EY to put up a "Why Rubinius?" page. And further, a "Which VM best targets my project? JRuby or Rubinius?" page would make me very happy. I can't imagine it could hurt the adoption of either.
andrewvc 15y ago
Jruby is working on cext support
- headius 15y ago
  C ext support shipped in an "experimental" form in JRuby 1.6. The main problem is that C extensions suck in so many ways: * Can't have multiple VMs in process, because C exts load all their state into C globals * Can't run them concurrently, because they can't be trusted not to segfault * Don't participate well in modern GCs, so they have significantly higher call overhead in JRuby or Rubinius than they do in MRI FFI is a better option in almost every case, although it is admittedly a much trickier path to cross-platform library binding. The best thing the Ruby community could do to move Ruby forward is to either come up with a better C API or start using FFI for everything. C exts suck.
headius 15y ago
Your reluctance to install Java on the servers you're on means you're missing out on one of the best Ruby implementations available. You'd be well served by putting aside your prejudice and just giving JRuby a try. That said, there's certainly domains where JRuby is not a great fit. C extension-heavy systems are one; because C extensions are so crippling to more modern VMs like the JVM or Rubinius, you're better off using the implementation the C API was designed for (MRI). Or if Rubinius suits your needs and C extensions work well enough, I'll recommend Rubinius over JRuby any day. I hate C extensions, or at least I hate them in the form they exist in MRI, since they're invasive and damaging to modern VM features like good GC and concurrent threads. In any case, it's worth seeing if FFI (the Ruby API that Rubinius pioneered and JRuby made generally available) serves your purposes, because it works extremely well in JRuby and requires no C extension support. And I'd suggest you actually give JRuby a try; it's so much more than "Ruby for Java interop" and may work better as a "plain old Ruby impl" than you expect.
- tptacek 15y ago
  I just used JRuby FFI to implement a native x86-64 debugger on WinAPI; we had x86 working for a long time on Win32, Linux, and OSX using MRI, and JRuby was actually the only way to get around LP64 issues with MRI. JRuby has been a compat and native code win for us; it is a better platform for accessing C code than MRI Ruby is.
  - headius 15y ago
    That's great to hear! Given that FFI is intended to work across all Ruby impls, I wish there were more attention paid to using FFI instead of C extensions. I will admit there are some usability problems, especially around cross-platform struct mapping, but the resulting libraries are vastly easier to deal with than a bunch of grotty Ruby C API code.
  - enebo 15y ago
    We have had other JRuby users state that most 64 bit stuff just works with JRuby and not so much with MRI. Thanks for sharing another example.
  - 15y ago

by mitchty 15y ago

ssmoot 15y ago

I don't use Rails. I see the JVM as a tool that gives me access to code I might find useful, and web-servers that are (IMO) 1000X superior to anything available to MRI. That and much better performance than REE anyways. If you need C-extensions, well, there you go. Rubinius as a better MRI I totally get/agree with. I think we agree on that as a good reason for the season for Rubinius. It'd just be nice for EY to put up a "Why Rubinius?" page. And further, a "Which VM best targets my project? JRuby or Rubinius?" page would make me very happy. I can't imagine it could hurt the adoption of either.

andrewvc 15y ago

Jruby is working on cext support

headius 15y ago
C ext support shipped in an "experimental" form in JRuby 1.6. The main problem is that C extensions suck in so many ways: * Can't have multiple VMs in process, because C exts load all their state into C globals * Can't run them concurrently, because they can't be trusted not to segfault * Don't participate well in modern GCs, so they have significantly higher call overhead in JRuby or Rubinius than they do in MRI FFI is a better option in almost every case, although it is admittedly a much trickier path to cross-platform library binding. The best thing the Ruby community could do to move Ruby forward is to either come up with a better C API or start using FFI for everything. C exts suck.

headius 15y ago

Your reluctance to install Java on the servers you're on means you're missing out on one of the best Ruby implementations available. You'd be well served by putting aside your prejudice and just giving JRuby a try. That said, there's certainly domains where JRuby is not a great fit. C extension-heavy systems are one; because C extensions are so crippling to more modern VMs like the JVM or Rubinius, you're better off using the implementation the C API was designed for (MRI). Or if Rubinius suits your needs and C extensions work well enough, I'll recommend Rubinius over JRuby any day. I hate C extensions, or at least I hate them in the form they exist in MRI, since they're invasive and damaging to modern VM features like good GC and concurrent threads. In any case, it's worth seeing if FFI (the Ruby API that Rubinius pioneered and JRuby made generally available) serves your purposes, because it works extremely well in JRuby and requires no C extension support. And I'd suggest you actually give JRuby a try; it's so much more than "Ruby for Java interop" and may work better as a "plain old Ruby impl" than you expect.

tptacek 15y ago
I just used JRuby FFI to implement a native x86-64 debugger on WinAPI; we had x86 working for a long time on Win32, Linux, and OSX using MRI, and JRuby was actually the only way to get around LP64 issues with MRI. JRuby has been a compat and native code win for us; it is a better platform for accessing C code than MRI Ruby is.
- headius 15y ago
  That's great to hear! Given that FFI is intended to work across all Ruby impls, I wish there were more attention paid to using FFI instead of C extensions. I will admit there are some usability problems, especially around cross-platform struct mapping, but the resulting libraries are vastly easier to deal with than a bunch of grotty Ruby C API code.
- enebo 15y ago
  We have had other JRuby users state that most 64 bit stuff just works with JRuby and not so much with MRI. Thanks for sharing another example.
- 15y ago