pmahoney

Orien is correct, it is the fork() system call triggered by ProcessBuilder or Runtime.exec or other means of the JVM executing an external process (e.g. another JVM running ant, a git command, etc.).

There have been some posts on the Jenkins mailing lists about this: Cannot run program "git" ... error=12, Cannot allocate memory

There is a nice description of the issue on the SCons dev list: fork()+exec() vs posix_spawn()

There is a long standing JVM bug report with solutions: Use posix_spawn, not fork, on S10 to avoid swap exhaustion. But I'm not sure if this actually made it into JDK7 as the comments suggest was the plan.

In summary, on Unix-like systems, when one process (e.g. the JVM) needs to launch another process (e.g. git) a system call is made to

pmahoney

... similar errors elided ...


 16) Error:
test_writing_with_not_nullable_column_encoded_with_JSON(StoreTest):
ActiveRecord::SerializationTypeMismatch: Attribute was supposed to be a ActiveSupport::HashWithIndifferentAccess, but was a Hash
    /home/pat/dev/ruby/rails/activerecord-mine/lib/active_record/coders/yaml_column.rb:34:in `load'
    /home/pat/dev/ruby/rails/activerecord-mine/lib/active_record/attribute_methods/serialization.rb:38:in `unserialize'
    /home/pat/dev/ruby/rails/activerecord-mine/lib/active_record/attribute_methods/serialization.rb:29:in `unserialized_value'
    /home/pat/dev/ruby/rails/activerecord-mine/lib/active_record/attribute_methods/serialization.rb:19:in `type_cast'

pmahoney

  <build>
    <resources>
      <resource>
        <directory>src/main/resources</directory>
      </resource>
      <resource>
        <directory>src/main/ruby</directory>
      </resource>
    </resources>
    ...

pmahoney

# Implements some part of the Servlet API in Ruby.  Does not extend
# javax.servlet.http.HttpServlet, but implements javax.servlet.Servlet
class MyServlet
  include Java::JavaxServlet::Servlet
  
  # @param [javax.servlet.ServletConfig] servletConfig
  def init(servletConfig)
  end
 
  def destroy

pmahoney

    # Runs maven if we are a JRuby process.  Currently not used.
    #
    # See http://watchitlater.com/blog/2011/08/jruby-rake-and-maven/
    def mvn(*args)
      mvn = catch(:mvn) do
        ENV['PATH'].split(::File::PATH_SEPARATOR).each do |path|
          Dir.glob(::File.join(path, 'mvn')).each do |file|
            if ::File.executable?(file)
              throw :mvn, if ::File.symlink?(file)
                            ::File.readlink(file)

pmahoney

#!/bin/sh
#
# bundle_exec.sh - emulate 'bundle exec' but with a shell script
# rather than a ruby script.  Modifies the environment just like
# bundle exec would.
#
# Running "bundle exec ruby" starts a ruby in which then execs the
# command, 'ruby'.  In JRuby 1.6, the command is started in a child
# process.  When using a Foreman-like tool that has the ability to
# kill and/or restart such a command, only the parent will be killed

pmahoney

GEM
  remote: http://rubygems.org/
  specs:
    activemodel (3.2.8)
      activesupport (= 3.2.8)
      builder (~> 3.0.0)
    activerecord (3.2.8)
      activemodel (= 3.2.8)
      activesupport (= 3.2.8)
      arel (~> 3.0.2)

pmahoney

require 'java'
require 'benchmark'

s = Java::JavaLang::String.new('hello')

n = 10000000
respond_task = proc { n.times { s.respond_to?(:to_s) || abort('error') } }
no_respond_task = proc { n.times { s.respond_to?(:no_method) && abort('error') } }
kind_of_task = proc { n.times { s.kind_of?(Java::JavaLang::String) || abort('error') } }
no_kind_of_task = proc { n.times { s.kind_of?(Java::JavaLang::Integer) && abort('error') } }

pmahoney

require 'java'

class Task
  include Java::JavaUtilConcurrent::Callable

  def initialize(num)
    @num = num
  end

  def call

pmahoney

public class Time {
    
    private final long timeInMillis;
    
    private final long nsec;
    
    public Time(long timeInMillis, long nsec) {
        this.timeInMillis = timeInMillis;
        this.nsec = nsec;
    }