Test codes to reproduce not thread-safe errors of Dynamoid

config.rb

require 'dynamoid'

Aws.config.update({
  region: 'us-west-2',
  credentials: Aws::Credentials.new('test', 'test'),
})

Dynamoid.configure do |config|
  config.endpoint = 'http://localhost:8000'
end

Dynamoid.logger.level = Logger::INFO

docker-compose.yml

version: '2'

services:
  dynamodb:
    image: amazon/dynamodb-local
    ports:
      - 8000:8000

document.rb

class Document
  include Dynamoid::Document

  table name: :documents, key: :identifier
end

Gemfile

# frozen_string_literal: true

source 'https://rubygems.org'

gem 'dynamoid'
gem 'pry-byebug', platforms: :ruby
gem 'rake'

Gemfile.lock

GEM
  remote: https://rubygems.org/
  specs:
    activemodel (5.2.3)
      activesupport (= 5.2.3)
    activesupport (5.2.3)
      concurrent-ruby (~> 1.0, >= 1.0.2)
      i18n (>= 0.7, < 2)
      minitest (~> 5.1)
      tzinfo (~> 1.1)
    aws-eventstream (1.0.3)
    aws-partitions (1.196.0)
    aws-sdk-core (3.62.0)
      aws-eventstream (~> 1.0, >= 1.0.2)
      aws-partitions (~> 1.0)
      aws-sigv4 (~> 1.1)
      jmespath (~> 1.0)
    aws-sdk-dynamodb (1.34.0)
      aws-sdk-core (~> 3, >= 3.61.1)
      aws-sigv4 (~> 1.1)
    aws-sigv4 (1.1.0)
      aws-eventstream (~> 1.0, >= 1.0.2)
    byebug (11.0.1)
    coderay (1.1.2)
    concurrent-ruby (1.1.5)
    dynamoid (3.2.0)
      activemodel (>= 4)
      aws-sdk-dynamodb (~> 1)
      concurrent-ruby (>= 1.0)
      null-logger
    i18n (1.6.0)
      concurrent-ruby (~> 1.0)
    jmespath (1.4.0)
    method_source (0.9.2)
    minitest (5.11.3)
    null-logger (0.1.5)
    pry (0.12.2)
      coderay (~> 1.1.0)
      method_source (~> 0.9.0)
    pry-byebug (3.7.0)
      byebug (~> 11.0)
      pry (~> 0.10)
    rake (12.3.3)
    thread_safe (0.3.6)
    tzinfo (1.2.5)
      thread_safe (~> 0.1)

PLATFORMS
  ruby

DEPENDENCIES
  dynamoid
  pry-byebug
  rake

BUNDLED WITH
   2.0.2

main.rb

require 'dynamoid'
require_relative 'config'
require_relative 'document'

def watchdog(name)
  yield
rescue Exception => ex
  puts "Thread name: \"#{name}\", Exception: \"#{ex}\""
end

def safe_thread(name, &block)
  Thread.new do
    Thread.current.name = name
    watchdog(name, &block)
  end
end

100.times do |i|
  safe_thread(i.to_s) do
    puts 'debug' # To unlock Ruby's GVL
    Document.where(identifier: 'hoge').first
  end
end

loop do
  sleep 5
end

Rakefile

Rake::Task.define_task(:environment)
require 'dynamoid/tasks'
require_relative 'config'
require_relative 'document'

namespace :dynamoid do
  desc 'Insert db seeds into DynamoDB'
  task :seed do
    begin
      Document.find('hoge')
    rescue Dynamoid::Errors::RecordNotFound
      Document.create(identifier: 'hoge')
    end
  end
end

How to setup

$ git clone https://gist.github.com/72e60233ed82a8a453428ea7441e6017.git reproduce-dynamoid-not-thread-safe
$ cd reproduce-dynamoid-not-thread-safe
$ docker-compose up -d
$ bundle
$ bundle exec rake dynamoid:create_tables
$ bundle exec rake dynamoid:seed

How to reproduce errors

$ bundle exec ruby main.rb
...
Thread name: "20", Exception: "undefined method `query' for #<Dynamoid::AdapterPlugin::AwsSdkV3:0x00007fdaf8bf2b08>
Did you mean?  to_query"
...
Thread name: "44", Exception: "undefined method `[]' for nil:NilClass"
...

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