Add EngineDetector and fix extension_helper path

It was polluting global Ruby load space

Author: pitr-ch

Rakefile

@@ -1,6 +1,6 @@
 #!/usr/bin/env rake
 
-require_relative './lib/extension_helper'
+require 'concurrent/extension_helper'
 
 ## load the two gemspec files
 CORE_GEMSPEC = Gem::Specification.load('concurrent-ruby.gemspec')
@@ -12,7 +12,7 @@ GEM_NAME = 'concurrent-ruby'
 EXTENSION_NAME = 'extension'
 JAVA_EXT_NAME = 'concurrent_ruby_ext'
 
-if Concurrent.jruby?
+if Concurrent.on_jruby?
   CORE_GEM = "#{GEM_NAME}-#{Concurrent::VERSION}-java.gem"
 else
   CORE_GEM = "#{GEM_NAME}-#{Concurrent::VERSION}.gem"
@@ -35,7 +35,7 @@ Dir.glob('tasks/**/*.rake').each do |rakefile|
   safe_load rakefile
 end
 
-if Concurrent.jruby?
+if Concurrent.on_jruby?
 
   ## create the compile task for the JRuby-specific gem
   require 'rake/javaextensiontask'
@@ -95,15 +95,15 @@ end
 namespace :build do
 
   build_deps = [:clean]
-  build_deps << :compile if Concurrent.jruby?
+  build_deps << :compile if Concurrent.on_jruby?
 
   desc "Build #{CORE_GEM} into the pkg directory"
   task :core => build_deps do
     sh "gem build #{CORE_GEMSPEC.name}.gemspec"
     sh 'mv *.gem pkg/'
   end
 
-  unless Concurrent.jruby?
+  unless Concurrent.on_jruby?
     desc "Build #{EXTENSION_GEM} into the pkg directory"
     task :ext => [:clean] do
       sh "gem build #{EXT_GEMSPEC.name}.gemspec"
@@ -120,7 +120,7 @@ namespace :build do
   end
 end
 
-if Concurrent.jruby?
+if Concurrent.on_jruby?
   desc 'Build JRuby-specific core gem (alias for `build:core`)'
   task :build => ['build:core']
 else

concurrent-ruby-ext.gemspec

@@ -20,7 +20,7 @@ Gem::Specification.new do |s|
 
   s.files            = Dir['ext/**/*.{h,c,cpp}']
   s.files           += [
-    'lib/extension_helper.rb',
+    'lib/concurrent/extension_helper.rb',
     'lib/concurrent/atomic_reference/concurrent_update_error.rb',
     'lib/concurrent/atomic_reference/direct_update.rb',
     'lib/concurrent/atomic_reference/numeric_cas_wrapper.rb',

ext/concurrent/extconf.rb

@@ -1,6 +1,6 @@
 require 'fileutils'
 
-require_relative '../../lib/extension_helper'
+require 'concurrent/extension_helper'
 
 EXTENSION_NAME = 'extension'
 

lib/concurrent/atomic.rb

@@ -3,16 +3,17 @@
 # user that they should use the new implementation instead.
 
 if defined?(Atomic)
-  warn <<-RUBY
+  warn <<-TXT
 [ATOMIC] Detected an `Atomic` class, which may indicate a dependency
 on the ruby-atomic gem. That gem has been deprecated and merged into
 the concurrent-ruby gem. Please use the Concurrent::Atomic class for
 atomic references and not the Atomic class.
-RUBY
+  TXT
 end
 #####################################################################
 
-require_relative '../extension_helper'
+require 'concurrent/extension_helper'
+require 'concurrent/utility/engine'
 require 'concurrent/atomic_reference/concurrent_update_error'
 require 'concurrent/atomic_reference/mutex_atomic'
 
@@ -21,7 +22,7 @@
   if /[^0fF]/ =~ ENV['FORCE_ATOMIC_FALLBACK']
     ruby_engine = 'mutex_atomic'
   else
-    ruby_engine = defined?(RUBY_ENGINE)? RUBY_ENGINE : 'ruby'
+    ruby_engine = Concurrent.ruby_engine
   end
 
   require "concurrent/atomic_reference/#{ruby_engine}"

lib/concurrent/atomic/atomic_boolean.rb

@@ -1,4 +1,4 @@
-require_relative '../../extension_helper'
+require 'concurrent/extension_helper'
 
 module Concurrent
 
@@ -113,7 +113,7 @@ def make_false
     end
   end
 
-  if RUBY_PLATFORM == 'java'
+  if Concurrent.on_jruby?
 
     class AtomicBoolean < JavaAtomicBoolean
     end

lib/concurrent/atomic/atomic_fixnum.rb

@@ -1,4 +1,4 @@
-require_relative '../../extension_helper'
+require 'concurrent/extension_helper'
 
 module Concurrent
 
@@ -118,7 +118,7 @@ def compare_and_set(expect, update)
     end
   end
 
-  if RUBY_PLATFORM == 'java'
+  if Concurrent.on_jruby?
 
     # @!macro atomic_fixnum
     class AtomicFixnum < JavaAtomicFixnum

lib/concurrent/atomic/count_down_latch.rb

@@ -69,7 +69,7 @@ def count
     end
   end
 
-  if RUBY_PLATFORM == 'java'
+  if Concurrent.on_jruby?
 
     # @!macro count_down_latch
     class JavaCountDownLatch

lib/concurrent/atomic/semaphore.rb

@@ -150,7 +150,7 @@ def try_acquire_timed(permits, timeout)
     end
   end
 
-  if RUBY_PLATFORM == 'java'
+  if Concurrent.on_jruby?
 
     # @!macro semaphore
     #

lib/concurrent/atomic/thread_local_var.rb

@@ -35,7 +35,7 @@ module ThreadLocalRubyStorage
 
       protected
 
-      unless RUBY_PLATFORM == 'java'
+      unless Concurrent.on_jruby?
         require 'ref'
       end
 
@@ -119,7 +119,7 @@ def bind(value, &block)
 
   # @!macro abstract_thread_local_var
   class ThreadLocalVar < AbstractThreadLocalVar
-    if RUBY_PLATFORM == 'java'
+    if Concurrent.on_jruby?
       include ThreadLocalJavaStorage
     else
       include ThreadLocalRubyStorage

lib/concurrent/atomic_reference/jruby.rb

@@ -1,4 +1,4 @@
-require_relative '../../extension_helper'
+require 'concurrent/extension_helper'
 
 if defined?(Concurrent::JavaAtomic)
   require 'concurrent/atomic_reference/direct_update'