jruby

BEFORE
                                              user     system      total        real
1m x10 yield 1 to { }                     2.648000   0.000000   2.648000 (  2.647000)
1m x10 yield to { }                       2.539000   0.000000   2.539000 (  2.539000)
1m x10 yield 1 to {|j| j}                 3.168000   0.000000   3.168000 (  3.168000)
1m x10 yield 1,2 to {|j,k| k}             3.643000   0.000000   3.643000 (  3.643000)
1m x10 yield 1,2,3 to {|j,k,l| k}         4.062000   0.000000   4.062000 (  4.063000)
1m x10 yield to {|j,k,l| k}               3.776000   0.000000   3.776000 (  3.776000)
1m x10 yield 1,2,3 to {|*j| j}            4.730000   0.000000   4.730000 (  4.730000)
1m x10 yield to {1}                       2.955000   0.000000   2.955000 (  2.955000)

jruby

~/projects/jruby ➔ gem install rails
fetching: http://gemcutter.org/quick/Marshal.4.8/rails-2.3.5.gemspec
fetching: http://gems.rubyforge.org/quick/Marshal.4.8/rails-2.3.5.gemspec
fetching: http://gemcutter.org/quick/Marshal.4.8/rake-0.8.7.gemspec
fetching: http://gems.rubyforge.org/quick/Marshal.4.8/rake-0.8.7.gemspec
fetching: http://gemcutter.org/quick/Marshal.4.8/activesupport-2.3.5.gemspec
fetching: http://gems.rubyforge.org/quick/Marshal.4.8/activesupport-2.3.5.gemspec
fetching: http://gemcutter.org/quick/Marshal.4.8/activerecord-2.3.5.gemspec
fetching: http://gems.rubyforge.org/quick/Marshal.4.8/activerecord-2.3.5.gemspec
fetching: http://gemcutter.org/quick/Marshal.4.8/actionpack-2.3.5.gemspec

jruby

~/projects/jruby/tmp ➔ cat blah.rb
class Foo
  def method(a, b)
  end

  class Bar
    def yummy(a, *b)
    end
  end
end

jruby

    public int hashCode() {
	int h = hash;
	if (h == 0) {
	    int off = offset;
	    char val[] = value;
	    int len = count;

            for (int i = 0; i < len; i++) {
                h = 31*h + val[off++];
            }

jruby

~/tmp/tmp2 ➔ ls -l
total 80
-rw-r--r--  1 headius  staff  1088 Dec 21 12:21 Marshal.4.8
-rw-r--r--  1 headius  staff   604 Dec 21 12:21 Marshal.4.8.Z
drwxr-xr-x  4 headius  staff   136 Dec 21 12:21 gems
-rw-r--r--  1 headius  staff    79 Dec 21 12:21 latest_specs.4.8
-rw-r--r--  1 headius  staff    88 Dec 21 12:21 latest_specs.4.8.gz
-rw-r--r--  1 headius  staff     4 Dec 21 12:21 prerelease_specs.4.8
-rw-r--r--  1 headius  staff    24 Dec 21 12:21 prerelease_specs.4.8.gz
drwxr-xr-x  9 headius  staff   306 Dec 21 12:21 quick

jruby

~/projects/jruby ➔ jruby -J-Xrunjdwp:transport=dt_socket,server=y,address=12345,suspend=n object_walker_test.rb
Listening for transport dt_socket at address: 12345
found object: I am Foo #0
found object: I am Foo #1
found object: I am Foo #2
found object: I am Foo #3
found object: I am Foo #4
found object: I am Foo #5
found object: I am Foo #6
found object: I am Foo #7

jruby

~/projects/jruby ➔ jruby -J-Xrunjdwp:transport=dt_socket,server=y,address=12345,suspend=n -S jirb
Listening for transport dt_socket at address: 12345
irb(main):001:0> require 'java'
=> true
irb(main):002:0> vmm = com.sun.jdi.Bootstrap.virtual_machine_manager
=> com.sun.tools.jdi.VirtualMachineManagerImpl@67fc9fee
irb(main):003:0> vmm.attaching_connectors
=> [com.sun.jdi.SocketAttach (defaults: timeout=, hostname=charles-nutters-macbook-pro.local, port=), com.sun.jdi.ProcessAttach (defaults: pid=, timeout=)]
irb(main):004:0> sock_attach = vmm.attaching_connectors[0]
=> com.sun.jdi.SocketAttach (defaults: timeout=, hostname=charles-nutters-macbook-pro.local, port=)

jruby

~/projects/jruby ➔ jruby -J-Xrunjdwp:transport=dt_socket,server=y,address=12345,suspend=n -S jirb
Listening for transport dt_socket at address: 12345
irb(main):001:0> require 'java'
=> true
irb(main):002:0> vmm = com.sun.jdi.Bootstrap.virtual_machine_manager
=> com.sun.tools.jdi.VirtualMachineManagerImpl@67fc9fee
irb(main):003:0> vmm.attaching_connectors
=> [com.sun.jdi.SocketAttach (defaults: timeout=, hostname=charles-nutters-macbook-pro.local, port=), com.sun.jdi.ProcessAttach (defaults: pid=, timeout=)]
irb(main):004:0> sock_attach = vmm.attaching_connectors[0]
=> com.sun.jdi.SocketAttach (defaults: timeout=, hostname=charles-nutters-macbook-pro.local, port=)

jruby

~/projects/jruby ➔ jirb
irb(main):001:0> require 'java'
=> true
irb(main):002:0> import com.sun.tools.attach.VirtualMachine
=> Java::ComSunToolsAttach::VirtualMachine
irb(main):003:0> vm = VirtualMachine.attach($$.to_s)
=> sun.tools.attach.MacosxAttachProvider@47875da7: 3294
irb(main):004:0> histo = vm.heap_histo([].to_java).to_io
=> #<IO:0x32b95f72>
irb(main):005:0> histo.lines.first(25).each {|line| puts line}; nil

jruby

   def setup
      if WINDOWS
         @block_dev = "NUL"
         @other_dev = "C:\\"
      else
         if File.exists?("/dev/fd0")
            @block_dev = "/dev/fd0"
         elsif File.exists?("/dev/diskette")
            @block_dev = "/dev/diskette"
         elsif File.exists?("/dev/cdrom")