apartment postgres threading issue

database.yml

development: &defaults
  adapter: postgresql
  database: app_development
  pool: 25
  encoding: unicode
  user: root
  password:

Gemfile

source 'https://rubygems.org'

gem 'apartment'
gem 'sidekiq'
gem 'rails'
gem 'pg'

Gemfile.lock

GEM
  remote: https://rubygems.org/
  specs:
    actionmailer (3.2.9)
      actionpack (= 3.2.9)
      mail (~> 2.4.4)
    actionpack (3.2.9)
      activemodel (= 3.2.9)
      activesupport (= 3.2.9)
      builder (~> 3.0.0)
      erubis (~> 2.7.0)
      journey (~> 1.0.4)
      rack (~> 1.4.0)
      rack-cache (~> 1.2)
      rack-test (~> 0.6.1)
      sprockets (~> 2.2.1)
    activemodel (3.2.9)
      activesupport (= 3.2.9)
      builder (~> 3.0.0)
    activerecord (3.2.9)
      activemodel (= 3.2.9)
      activesupport (= 3.2.9)
      arel (~> 3.0.2)
      tzinfo (~> 0.3.29)
    activeresource (3.2.9)
      activemodel (= 3.2.9)
      activesupport (= 3.2.9)
    activesupport (3.2.9)
      i18n (~> 0.6)
      multi_json (~> 1.0)
    apartment (0.18.0)
      activerecord (>= 3.1.2)
      rack (>= 1.3.6)
    arel (3.0.2)
    builder (3.0.4)
    celluloid (0.12.3)
      facter (>= 1.6.12)
      timers (>= 1.0.0)
    connection_pool (0.9.2)
    erubis (2.7.0)
    facter (1.6.15)
    hike (1.2.1)
    i18n (0.6.1)
    journey (1.0.4)
    json (1.7.5)
    mail (2.4.4)
      i18n (>= 0.4.0)
      mime-types (~> 1.16)
      treetop (~> 1.4.8)
    mime-types (1.19)
    multi_json (1.3.7)
    pg (0.14.0)
    polyglot (0.3.3)
    rack (1.4.1)
    rack-cache (1.2)
      rack (>= 0.4)
    rack-ssl (1.3.2)
      rack
    rack-test (0.6.2)
      rack (>= 1.0)
    rails (3.2.9)
      actionmailer (= 3.2.9)
      actionpack (= 3.2.9)
      activerecord (= 3.2.9)
      activeresource (= 3.2.9)
      activesupport (= 3.2.9)
      bundler (~> 1.0)
      railties (= 3.2.9)
    railties (3.2.9)
      actionpack (= 3.2.9)
      activesupport (= 3.2.9)
      rack-ssl (~> 1.3.2)
      rake (>= 0.8.7)
      rdoc (~> 3.4)
      thor (>= 0.14.6, < 2.0)
    rake (10.0.2)
    rdoc (3.12)
      json (~> 1.4)
    redis (3.0.2)
    redis-namespace (1.2.1)
      redis (~> 3.0.0)
    sidekiq (2.5.4)
      celluloid (~> 0.12.0)
      connection_pool (~> 0.9.2)
      multi_json (~> 1)
      redis (~> 3)
      redis-namespace
    sprockets (2.2.2)
      hike (~> 1.2)
      multi_json (~> 1.0)
      rack (~> 1.0)
      tilt (~> 1.1, != 1.3.0)
    thor (0.16.0)
    tilt (1.3.3)
    timers (1.0.1)
    treetop (1.4.12)
      polyglot
      polyglot (>= 0.3.1)
    tzinfo (0.3.35)

PLATFORMS
  ruby

DEPENDENCIES
  apartment
  pg
  rails
  sidekiq

thread_schema_problem.rb

#!/usr/bin/env ruby

require "rubygems"
require "bundler/setup"
require 'rails/all'
require 'apartment'

class Worker
  WORKER_COUNT = 20
  SCHEMA_NAMES = (1..5).to_a.map {|n| "company_#{n}" }

  def initialize
    @connection = Apartment.connection
  end

  def spawn
    puts "#{self.class} starting"
    WORKER_COUNT.times.map do
      Thread.new do
        perform
      end
    end.each do |th|
      th.join
    end
    puts "#{self.class} done"
  end

  def perform
    ActiveRecord::Base.connection_pool.with_connection do |connection|
      stash_name
      connection.schema_search_path = Thread.current[:name]
      # sleep rand(3)
      check(connection)
    end
  end

  def check(connection)
    # result = connection.execute("SELECT COUNT(*) FROM reminders;")
    # printf "result: %s, company: %s\n", result.values[0], Thread.current[:name]
    printf "%s: %s :%s\n",
      Thread.current[:name],
      connection.schema_search_path,
      Thread.current[:name] == connection.schema_search_path
  end

  def stash_name
    name = SCHEMA_NAMES.sample
    Thread.current[:name] = name
  end

  def connection_info(current_connection)
    printf "main: %s, apartment: %s, ar: %s con: %s\n", @connection.object_id, Apartment.connection.object_id, ActiveRecord::Base.connection.object_id, current_connection.object_id
  end
end

class PooledApartmentWorker < Worker
  def perform
    ActiveRecord::Base.connection_pool.with_connection do |connection|
      stash_name
      Apartment::Database.switch(Thread.current[:name])
      check(Apartment.connection)
    end
  end
end

class ApartmentWorker < Worker
  # Broken
  def perform
    stash_name
    Apartment::Database.switch(Thread.current[:name])
    check(@connection)
  end
end

Apartment.configure do |config|
  config.database_names = Worker::SCHEMA_NAMES
end

class MyApp < Rails::Application
  config.active_support.deprecation = :log
  config.threadsafe!
end

MyApp.initialize!
Apartment.connection
Worker.new.spawn
PooledApartmentWorker.new.spawn
# ApartmentWorker.new.spawn