ActiveRecord threadsafe test

active_record_test.rb

require 'active_record'

puts "Active Record #{ActiveRecord::VERSION::STRING}"

# TODO: How to get past sqlite3_connection undefined error?
# ActiveRecord::Base.establish_connection(
#   :adapter  => 'jdbcsqlite3',
#   :database => ':memory:'
# )
ActiveRecord::Base.establish_connection(
  adapter:  'mysql2',
  database: 'foobar',
  # Needed for Rails 4.2
  pool:     100
)

ActiveRecord::Schema.define do
  create_table :foos, force: true do |t|
    100.times do |i|
      t.boolean "field#{i}".to_sym, :boolean
    end
  end
end

class Foo < ActiveRecord::Base
  if ENV['FIX_FOO']
    after_initialize :mutexize_attributes
    def mutexize_attributes
      mutex = Mutex.new
      class << attributes
        def []=(attr, val)
          mutex.synchronize { super }
        end
      end
    end
  end
end

10.times do
  foo = Foo.new
  (0..99).map do |i|
    Thread.new(i) do |i|
      foo.send("field#{i}=", true)
    end
  end.each {|t| t.join}
  attrs = foo.attributes.reject {|k,v| v==true || v==1 || ['id','boolean'].include?(k)}
  puts attrs.inspect
end