Moved C extensions into a companion gem.

Gemfile

@@ -8,6 +8,7 @@ group :development do
 end
 
 group :testing do
+  gem 'concurrent-ruby-ext', :platforms => :mri, git: 'https://github.com/ruby-concurrency/concurrent-ruby-ext', branch: 'master'
   gem 'rspec', '~> 3.0.0'
   gem 'simplecov', '~> 0.8.2', :require => false
   gem 'coveralls', '~> 0.7.0', :require => false

README.md

@@ -38,9 +38,7 @@
 ### Supported Ruby versions
 
 MRI 1.9.3, 2.0, 2.1, JRuby (1.9 mode), and Rubinius 2.x are supported.
-Although native code is used for performance optimizations on some platforms, all functionality
-is available in pure Ruby. This gem should be fully compatible with any interpreter that is
-compliant with Ruby 1.9.3 or newer.
+This gem should be fully compatible with any interpreter that is compliant with Ruby 1.9.3 or newer.
 
 ## Features & Documentation
 
@@ -96,30 +94,7 @@ Lower-level abstractions mainly used as building blocks.
 * [thread-local variables](http://ruby-concurrency.github.io/concurrent-ruby/Concurrent/ThreadLocalVar.html)
 * [software transactional memory](./doc/tvar.md) (TVar)
 
-
-
-## Installing and Building
-
-This gem includes several platform-specific optimizations. To reduce the possibility of
-compilation errors, we provide pre-compiled gem packages for several platforms as well
-as a pure-Ruby build. Installing the gem should be no different than installing any other
-Rubygems-hosted gem. Rubygems will automatically detect your platform and install the
-appropriate pre-compiled build. You should never see Rubygems attempt to compile the gem
-on installation. Additionally, to ensure compatability with the largest possible number
-of Ruby interpreters, the C extensions will *never* load under any Ruby other than MRI,
-even when installed.
-
-The following gem builds will be built at every release:
-
-* concurrent-ruby-x.y.z.gem (pure Ruby)
-* concurrent-ruby-x.y.z-java.gem (JRuby)
-* concurrent-ruby-x.y.z-x86-linux.gem (Linux 32-bit)
-* concurrent-ruby-x.y.z-x86_64-linux.gem (Linux 64-bit)
-* concurrent-ruby-x.y.z-x86-mingw32.gem (Windows 32-bit)
-* concurrent-ruby-x.y.z-x64-mingw32.gem (Windows 64-bit)
-* concurrent-ruby-x.y.z-x86-solaris-2.11.gem (Solaris)
-
-### Installing
+## Installing
 
 ```shell
 gem install concurrent-ruby
@@ -133,31 +108,28 @@ gem 'concurrent-ruby'
 
 and run `bundle install` from your shell.
 
-### Building
+### Installing Optional C Extensions (MRI)
 
-Because we provide pre-compiled gem builds, users should never need to build the gem manually.
-The build process for this gem is completely automated using open source tools. All of
-the automation components are available in the [ruby-concurrency/rake-compiler-dev-box](https://github.com/ruby-concurrency/rake-compiler-dev-box)
-GitHub repository.
+For improved performance on MRI a compantion gem with called `concurrent-ruby-ext` is provided. When the
+extensions are installed `concurrent-ruby` will detect their presence and automatically load them.
 
-This gem will compile native C code under MRI and native Java code under JRuby. It is
-also possible to build a pure-Ruby version. All builds have identical functionality.
-The only difference is performance. Additionally, pure-Ruby classes are always available,
-even when using the native optimizations. Please see the [documentation](http://ruby-concurrency.github.io/concurrent-ruby/)
-for more details.
+```shell
+gem install concurrent-ruby-ext
+```
 
-To build and package the gem using MRI or JRuby, install the necessary build dependencies and run:
+or add the following line to Gemfile:
 
-```shell
-bundle exec rake compile
-bundle exec rake build
+```ruby
+gem 'concurrent-ruby'-ext
 ```
 
-To build and package a pure-Ruby gem, on *any* platform and interpreter
-(including MRI and JRuby), run:
+and run `bundle install` from your shell.
 
-```shell
-BUILD_PURE_RUBY='true' bundle exec rake build
+In your code make sure you require the extension gem **before** you require the core gem:
+
+```ruby
+require 'concurrent_ext'
+require 'concurrent'
 ```
 
 ## Maintainers

Rakefile

@@ -34,30 +34,6 @@ if defined?(JRUBY_VERSION)
     ext.ext_dir = 'ext'
   end
 
-elsif Concurrent.allow_c_extensions?
-
-  Rake::ExtensionTask.new(EXTENSION_NAME, GEMSPEC) do |ext|
-    ext.ext_dir = "ext/#{EXTENSION_NAME}"
-    ext.cross_compile = true
-    ext.cross_platform = ['x86-mingw32', 'x64-mingw32']
-  end
-
-  ENV['RUBY_CC_VERSION'].to_s.split(':').each do |ruby_version|
-    platforms = {
-      'x86-mingw32' => 'i686-w64-mingw32',
-      'x64-mingw32' => 'x86_64-w64-mingw32'
-    }
-    platforms.each do |platform, prefix|
-      task "copy:#{EXTENSION_NAME}:#{platform}:#{ruby_version}" do |t|
-        %w[lib tmp/#{platform}/stage/lib].each do |dir|
-          so_file = "#{dir}/#{ruby_version[/^\d+\.\d+/]}/#{EXTENSION_NAME}.so"
-          if File.exists?(so_file)
-            sh "#{prefix}-strip -S #{so_file}"
-          end
-        end
-      end
-    end
-  end
 else
   task :clean
   task :compile
@@ -67,10 +43,7 @@ end
 Rake::Task[:clean].enhance do
   rm_rf 'pkg/classes'
   rm_rf 'tmp'
-  rm_rf 'lib/1.9'
-  rm_rf 'lib/2.0'
   rm_f Dir.glob('./lib/*.jar')
-  rm_f Dir.glob('./**/*.bundle')
 end
 
 begin

concurrent-ruby.gemspec

@@ -25,14 +25,9 @@ Gem::Specification.new do |s|
   if defined?(JRUBY_VERSION)
     s.files += Dir['lib/concurrent_ruby_ext.jar']
     s.platform = 'java'
-  elsif ! ENV['BUILD_PURE_RUBY']
-    s.extensions = 'ext/concurrent_ruby_ext/extconf.rb'
-    s.files += Dir['ext/**/*.{h,c,cpp}']
+  else
+    s.add_dependency 'ref', '~> 1.0.5'
   end
 
   s.required_ruby_version = '>= 1.9.3'
-
-  unless defined?(JRUBY_VERSION)
-    s.add_dependency 'ref', '~> 1.0.5'
-  end
 end