Undefined method read_uint64 in JRuby.

[Adithya-copart]

I noticed this error in my Macbook while trying to run ProcTable.ps(:pid => Process.pid).cmdline.split(' ').

jruby-head :001 > RUBY_VERSION
 => "2.5.3" 
jruby-head :002 > require 'sys/proctable'
 => true 
jruby-head :003 > include Sys
 => Object 
jruby-head :004 > ProcTable.ps(:pid => Process.pid).cmdline.split(' ')
Traceback (most recent call last):
       10: from /Users/adpentela/.rvm/rubies/jruby-head/bin/irb:13:in `<main>'
        9: from org/jruby/RubyKernel.java:1193:in `catch'
        8: from org/jruby/RubyKernel.java:1193:in `catch'
        7: from org/jruby/RubyKernel.java:1425:in `loop'
        6: from org/jruby/RubyKernel.java:1061:in `eval'
        5: from (irb):4:in `evaluate'
        4: from /Users/adpentela/.rvm/gems/jruby-head/gems/sys-proctable-1.2.1/lib/darwin/sys/proctable.rb:199:in `ps'
        3: from /Users/adpentela/.rvm/gems/jruby-head/gems/sys-proctable-1.2.1/lib/darwin/sys/proctable.rb:286:in `get_thread_info'
        2: from org/jruby/RubyInteger.java:209:in `upto'
        1: from /Users/adpentela/.rvm/gems/jruby-head/gems/sys-proctable-1.2.1/lib/darwin/sys/proctable.rb:288:in `block in get_thread_info'
NoMethodError (undefined method `read_uint64' for #<FFI::Pointer address=0x7f81cee78510 size=208>)
Did you mean?  read_uint
               read_int
               get_uint64
jruby-head :005 > 

I tried to see if I can get this working by using the alternatives suggested in the error message but it still results in an error.

Here are my environment specifics:

$ uname -a
Darwin MB-ADPENTELA.local 17.4.0 Darwin Kernel Version 17.4.0: Sun Dec 17 09:19:54 PST 2017; root:xnu-4570.41.2~1/RELEASE_X86_64 x86_64

$ ruby -v
jruby 9.2.7.0 (2.5.3) 2019-04-09 8a269e3 Java HotSpot(TM) 64-Bit Server VM 25.191-b12 on 1.8.0_191-b12 +jit [darwin-x86_64]

$ java -version
java version "1.8.0_191"
Java(TM) SE Runtime Environment (build 1.8.0_191-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.191-b12, mixed mode)

[djberg96]

Hm, worked ok with 9.2.4.0 on my Linux laptop. I'll have to wait until this evening to test it against my Mac.

[Adithya-copart]

@djberg96 It fails on my Macbook when I try irb using JRuby.
I tried replacing read_uint64 with get_uint64 and FFI::StructLayout::CharArray with FFI::StructLayout::CHAR_ARRAY.

I gave up after it failed with both those changes. It works fine with MRI Ruby and also within a JRuby docker container running on my mac.

[djberg96]

@Adithya-copart Try read_ulong_long and see how that goes.

[Adithya-copart]

With read_ulong_ulong

jruby-9.2.7.0 :003 > ProcTable.ps(:pid => Process.pid).cmdline.split(' ')
Traceback (most recent call last):
       13: from /Users/adpentela/.rvm/rubies/jruby-9.2.7.0/bin/irb:13:in `<main>'
       12: from org/jruby/RubyKernel.java:1193:in `catch'
       11: from org/jruby/RubyKernel.java:1193:in `catch'
       10: from org/jruby/RubyKernel.java:1425:in `loop'
        9: from org/jruby/RubyKernel.java:1061:in `eval'
        8: from (irb):3:in `evaluate'
        7: from /Users/adpentela/.rvm/gems/jruby-9.2.7.0/gems/sys-proctable-1.2.1/lib/darwin/sys/proctable.rb:200:in `ps'
        6: from /Users/adpentela/.rvm/gems/jruby-9.2.7.0/gems/sys-proctable-1.2.1/lib/darwin/sys/proctable.rb:258:in `apply_info_to_struct'
        5: from org/jruby/RubyArray.java:1792:in `each'
        4: from /Users/adpentela/.rvm/gems/jruby-9.2.7.0/gems/sys-proctable-1.2.1/lib/darwin/sys/proctable.rb:259:in `block in apply_info_to_struct'
        3: from org/jruby/RubyArray.java:1792:in `each'
        2: from /Users/adpentela/.rvm/gems/jruby-9.2.7.0/gems/sys-proctable-1.2.1/lib/darwin/sys/proctable.rb:260:in `block in apply_info_to_struct'
        1: from org/jruby/RubyModule.java:3742:in `const_missing'
NameError (uninitialized constant FFI::StructLayout::CharArray)
Did you mean?  FFI::StructLayout::CHAR_ARRAY

Used FFI::StructLayout::CHAR_ARRAY here:

jruby-9.2.7.0 :003 > ProcTable.ps(:pid => Process.pid).cmdline.split(' ')
Traceback (most recent call last):
       13: from /Users/adpentela/.rvm/rubies/jruby-9.2.7.0/bin/irb:13:in `<main>'
       12: from org/jruby/RubyKernel.java:1193:in `catch'
       11: from org/jruby/RubyKernel.java:1193:in `catch'
       10: from org/jruby/RubyKernel.java:1425:in `loop'
        9: from org/jruby/RubyKernel.java:1061:in `eval'
        8: from (irb):3:in `evaluate'
        7: from /Users/adpentela/.rvm/gems/jruby-9.2.7.0/gems/sys-proctable-1.2.1/lib/darwin/sys/proctable.rb:200:in `ps'
        6: from /Users/adpentela/.rvm/gems/jruby-9.2.7.0/gems/sys-proctable-1.2.1/lib/darwin/sys/proctable.rb:258:in `apply_info_to_struct'
        5: from org/jruby/RubyArray.java:1792:in `each'
        4: from /Users/adpentela/.rvm/gems/jruby-9.2.7.0/gems/sys-proctable-1.2.1/lib/darwin/sys/proctable.rb:259:in `block in apply_info_to_struct'
        3: from org/jruby/RubyArray.java:1792:in `each'
        2: from /Users/adpentela/.rvm/gems/jruby-9.2.7.0/gems/sys-proctable-1.2.1/lib/darwin/sys/proctable.rb:260:in `block in apply_info_to_struct'
        1: from org/jruby/RubyKernel.java:2096:in `kind_of?'
TypeError (class or module required)
jruby-9.2.7.0 :004 > 

[djberg96]

@Adithya-copart What version of ffi are you using?

[Adithya-copart]

Thanks for looking into this @djberg96 .

I got the same error using ffi '1.11.1' and '1.9.6' from github by adding this to my Gemfile:

  gem 'ffi', git: "git://github.com/ffi/ffi.git", tag: 'v1.9.6'

$ bundle show ffi
/Users/adpentela/.rvm/gems/jruby-9.2.7.0/gems/ffi-1.11.1-java

$ bundle update ffi
Fetching gem metadata from https://rubygems.org/...........
Fetching gem metadata from https://rubygems.org/.
.....
Using ffi 1.11.1 (java)
....
Bundler attempted to update ffi but its version stayed the same
Bundle updated!

[djberg96]

@Adithya-copart I think we can get around the lack of read_uint64 with read_array_of_uint64(1).first.

I'm not sure what's going on with the char array thing yet.

[djberg96]

@Adithya-copart Looks like this will workaround will work for the CharArray issue:

unless defined? FFI::StructLayout::CharArray
    FFI::StructLayout::CharArray = FFI::StructLayout::CharArrayProxy
end

[Adithya-copart]

@djberg96 Thanks, can confirm that this works on JRuby.

[djberg96]

Fixed by #78 and part of the 1.2.2 release. Thanks for the report!

[Adithya-copart]

The conditional introduced due to the lack of read_uint64 in #78 can be removed if ffi/ffi#717 is resolved.

[djberg96]

@Adithya-copart Thanks, please remind me if/when that issue is addressed.

[headius]

This will be fixed for jruby/jruby#5947 by jruby/jruby#5948. Thanks for working around it! Hopefully with the FFIs synched up we won't see these sorts of incompatibilities.

[adi-pen]

@Adithya-copart Thanks, please remind me if/when that issue is addressed.

@djberg96 https://www.jruby.org/2021/09/22/jruby-9-3-0-0.html is out and it includes the above fix @headius mentioned.

[djberg96]

@adi-pen Thanks. I'll probably wait a while to remove the previous changes since I imagine people will be running older versions of JRuby for a time.