Reorganize autoloads:

  * A new module (ActiveSupport::Autoload) is provide that extends
    autoloading with new behavior.
  * All autoloads in modules that have extended ActiveSupport::Autoload
    will be eagerly required in threadsafe environments
  * Autoloads can optionally leave off the path if the path is the same
    as full_constant_name.underscore
  * It is possible to specify that a group of autoloads live under an
    additional path. For instance, all of ActionDispatch's middlewares
    are ActionDispatch::MiddlewareName, but they live under 
    "action_dispatch/middlewares/middleware_name"
  * It is possible to specify that a group of autoloads are all found
    at the same path. For instance, a number of exceptions might all
    be declared there.
  * One consequence of this is that testing-related constants are not
    autoloaded. To get the testing helpers for a given component,
    require "component_name/test_case". For instance, "action_controller/test_case".
  * test_help.rb, which is automatically required by a Rails application's
    test helper, requires the test_case.rb for all active components, so
    this change will not be disruptive in existing or new applications.

6 files changed, 491 insertions, 363 deletions

diff --git a/activesupport/lib/active_support/autoload.rb b/activesupport/lib/active_support/autoload.rb
index 63f7338a68..e57cf24b25 100644
--- a/activesupport/lib/active_support/autoload.rb
+++ b/activesupport/lib/active_support/autoload.rb
@@ -1,28 +1,31 @@
+require "active_support/dependencies/autoload"
+
 module ActiveSupport
-  autoload :BacktraceCleaner, 'active_support/backtrace_cleaner'
-  autoload :Base64, 'active_support/base64'
-  autoload :BasicObject, 'active_support/basic_object'
-  autoload :Benchmarkable, 'active_support/benchmarkable'
-  autoload :BufferedLogger, 'active_support/buffered_logger'
-  autoload :Cache, 'active_support/cache'
-  autoload :Callbacks, 'active_support/callbacks'
-  autoload :Concern, 'active_support/concern'
-  autoload :Configurable, 'active_support/configurable'
-  autoload :DependencyModule, 'active_support/dependency_module'
-  autoload :DeprecatedCallbacks, 'active_support/deprecated_callbacks'
-  autoload :Deprecation, 'active_support/deprecation'
-  autoload :Gzip, 'active_support/gzip'
-  autoload :Inflector, 'active_support/inflector'
-  autoload :Memoizable, 'active_support/memoizable'
-  autoload :MessageEncryptor, 'active_support/message_encryptor'
-  autoload :MessageVerifier, 'active_support/message_verifier'
-  autoload :Multibyte, 'active_support/multibyte'
-  autoload :OptionMerger, 'active_support/option_merger'
-  autoload :OrderedHash, 'active_support/ordered_hash'
-  autoload :OrderedOptions, 'active_support/ordered_options'
-  autoload :Notifications, 'active_support/notifications'
-  autoload :Rescuable, 'active_support/rescuable'
-  autoload :SecureRandom, 'active_support/secure_random'
-  autoload :StringInquirer, 'active_support/string_inquirer'
-  autoload :XmlMini, 'active_support/xml_mini'
+  extend ActiveSupport::Autoload
+
+  autoload :BacktraceCleaner
+  autoload :Base64
+  autoload :BasicObject
+  autoload :Benchmarkable
+  autoload :BufferedLogger
+  autoload :Cache
+  autoload :Callbacks
+  autoload :Concern
+  autoload :Configurable
+  autoload :DeprecatedCallbacks
+  autoload :Deprecation
+  autoload :Gzip
+  autoload :Inflector
+  autoload :Memoizable
+  autoload :MessageEncryptor
+  autoload :MessageVerifier
+  autoload :Multibyte
+  autoload :OptionMerger
+  autoload :OrderedHash
+  autoload :OrderedOptions
+  autoload :Notifications
+  autoload :Rescuable
+  autoload :SecureRandom
+  autoload :StringInquirer
+  autoload :XmlMini
 end
diff --git a/activesupport/lib/active_support/dependencies/autoload.rb b/activesupport/lib/active_support/dependencies/autoload.rb
new file mode 100644
index 0000000000..973875f895
--- /dev/null
+++ b/activesupport/lib/active_support/dependencies/autoload.rb
@@ -0,0 +1,37 @@
+require "active_support/inflector/methods"
+
+module ActiveSupport
+  module Autoload
+
+    @@autoloads = {}
+    @@under_path = nil
+    @@at_path = nil
+
+    def autoload(const_name, path = @@at_path)
+      full = [self.name, @@under_path, const_name.to_s, path].compact.join("::")
+      location = path || Inflector.underscore(full)
+
+      @@autoloads[const_name] = location
+      super const_name, location
+    end
+
+    def autoload_under(path)
+      @@under_path, old_path = path, @@under_path
+      yield
+    ensure
+      @@under_path = old_path
+    end
+
+    def autoload_at(path)
+      @@at_path, old_path = path, @@at_path
+      yield
+    ensure
+      @@at_path = old_path
+    end
+
+    def self.eager_autoload!
+      @@autoloads.values.each {|file| require file }
+    end
+
+  end
+end
\ No newline at end of file
diff --git a/activesupport/lib/active_support/testing/performance.rb b/activesupport/lib/active_support/testing/performance.rb
index ab34f975f6..66e32fa5d7 100644
--- a/activesupport/lib/active_support/testing/performance.rb
+++ b/activesupport/lib/active_support/testing/performance.rb
@@ -1,450 +1,454 @@
-require 'ruby-prof'
-
-require 'fileutils'
-require 'rails/version'
-
-module ActiveSupport
-  module Testing
-    module Performance
-      DEFAULTS =
-        if benchmark = ARGV.include?('--benchmark')  # HAX for rake test
-          { :benchmark => true,
-            :runs => 4,
-            :metrics => [:wall_time, :memory, :objects, :gc_runs, :gc_time],
-            :output => 'tmp/performance' }
-        else
-          { :benchmark => false,
-            :runs => 1,
-            :min_percent => 0.01,
-            :metrics => [:process_time, :memory, :objects],
-            :formats => [:flat, :graph_html, :call_tree],
-            :output => 'tmp/performance' }
-        end.freeze
-
-      def self.included(base)
-        base.superclass_delegating_accessor :profile_options
-        base.profile_options = DEFAULTS
-      end
+begin
+  require 'ruby-prof'
+
+  require 'fileutils'
+  require 'rails/version'
+  require 'active_support/core_ext/class/delegating_attributes'
+
+  module ActiveSupport
+    module Testing
+      module Performance
+        DEFAULTS =
+          if benchmark = ARGV.include?('--benchmark')  # HAX for rake test
+            { :benchmark => true,
+              :runs => 4,
+              :metrics => [:wall_time, :memory, :objects, :gc_runs, :gc_time],
+              :output => 'tmp/performance' }
+          else
+            { :benchmark => false,
+              :runs => 1,
+              :min_percent => 0.01,
+              :metrics => [:process_time, :memory, :objects],
+              :formats => [:flat, :graph_html, :call_tree],
+              :output => 'tmp/performance' }
+          end.freeze
+
+        def self.included(base)
+          base.superclass_delegating_accessor :profile_options
+          base.profile_options = DEFAULTS
+        end
 
-      def full_test_name
-        "#{self.class.name}##{method_name}"
-      end
+        def full_test_name
+          "#{self.class.name}##{method_name}"
+        end
 
-      def run(result)
-        return if method_name =~ /^default_test$/
+        def run(result)
+          return if method_name =~ /^default_test$/
 
-        yield(self.class::STARTED, name)
-        @_result = result
+          yield(self.class::STARTED, name)
+          @_result = result
 
-        run_warmup
-        if profile_options && metrics = profile_options[:metrics]
-          metrics.each do |metric_name|
-            if klass = Metrics[metric_name.to_sym]
-              run_profile(klass.new)
-              result.add_run
+          run_warmup
+          if profile_options && metrics = profile_options[:metrics]
+            metrics.each do |metric_name|
+              if klass = Metrics[metric_name.to_sym]
+                run_profile(klass.new)
+                result.add_run
+              end
             end
           end
-        end
 
-        yield(self.class::FINISHED, name)
-      end
+          yield(self.class::FINISHED, name)
+        end
 
-      def run_test(metric, mode)
-        run_callbacks :setup
-        setup
-        metric.send(mode) { __send__ @method_name }
-      rescue ::Test::Unit::AssertionFailedError => e
-        add_failure(e.message, e.backtrace)
-      rescue StandardError, ScriptError
-        add_error($!)
-      ensure
-        begin
-          teardown
-          run_callbacks :teardown, :enumerator => :reverse_each
+        def run_test(metric, mode)
+          run_callbacks :setup
+          setup
+          metric.send(mode) { __send__ @method_name }
         rescue ::Test::Unit::AssertionFailedError => e
           add_failure(e.message, e.backtrace)
         rescue StandardError, ScriptError
           add_error($!)
+        ensure
+          begin
+            teardown
+            run_callbacks :teardown, :enumerator => :reverse_each
+          rescue ::Test::Unit::AssertionFailedError => e
+            add_failure(e.message, e.backtrace)
+          rescue StandardError, ScriptError
+            add_error($!)
+          end
         end
-      end
 
-      protected
-        def run_warmup
-          GC.start
+        protected
+          def run_warmup
+            GC.start
 
-          time = Metrics::Time.new
-          run_test(time, :benchmark)
-          puts "%s (%s warmup)" % [full_test_name, time.format(time.total)]
+            time = Metrics::Time.new
+            run_test(time, :benchmark)
+            puts "%s (%s warmup)" % [full_test_name, time.format(time.total)]
 
-          GC.start
-        end
-
-        def run_profile(metric)
-          klass = profile_options[:benchmark] ? Benchmarker : Profiler
-          performer = klass.new(self, metric)
+            GC.start
+          end
 
-          performer.run
-          puts performer.report
-          performer.record
-        end
+          def run_profile(metric)
+            klass = profile_options[:benchmark] ? Benchmarker : Profiler
+            performer = klass.new(self, metric)
 
-      class Performer
-        delegate :run_test, :profile_options, :full_test_name, :to => :@harness
+            performer.run
+            puts performer.report
+            performer.record
+          end
 
-        def initialize(harness, metric)
-          @harness, @metric = harness, metric
-        end
+        class Performer
+          delegate :run_test, :profile_options, :full_test_name, :to => :@harness
 
-        def report
-          rate = @total / profile_options[:runs]
-          '%20s: %s' % [@metric.name, @metric.format(rate)]
-        end
+          def initialize(harness, metric)
+            @harness, @metric = harness, metric
+          end
 
-        protected
-          def output_filename
-            "#{profile_options[:output]}/#{full_test_name}_#{@metric.name}"
+          def report
+            rate = @total / profile_options[:runs]
+            '%20s: %s' % [@metric.name, @metric.format(rate)]
           end
-      end
 
-      class Benchmarker < Performer
-        def run
-          profile_options[:runs].to_i.times { run_test(@metric, :benchmark) }
-          @total = @metric.total
+          protected
+            def output_filename
+              "#{profile_options[:output]}/#{full_test_name}_#{@metric.name}"
+            end
         end
 
-        def record
-          avg = @metric.total / profile_options[:runs].to_i
-          now = Time.now.utc.xmlschema
-          with_output_file do |file|
-            file.puts "#{avg},#{now},#{environment}"
+        class Benchmarker < Performer
+          def run
+            profile_options[:runs].to_i.times { run_test(@metric, :benchmark) }
+            @total = @metric.total
           end
-        end
 
-        def environment
-          unless defined? @env
-            app = "#{$1}.#{$2}" if File.directory?('.git') && `git branch -v` =~ /^\* (\S+)\s+(\S+)/
-
-            rails = Rails::VERSION::STRING
-            if File.directory?('vendor/rails/.git')
-              Dir.chdir('vendor/rails') do
-                rails += ".#{$1}.#{$2}" if `git branch -v` =~ /^\* (\S+)\s+(\S+)/
-              end
+          def record
+            avg = @metric.total / profile_options[:runs].to_i
+            now = Time.now.utc.xmlschema
+            with_output_file do |file|
+              file.puts "#{avg},#{now},#{environment}"
             end
-
-            ruby = defined?(RUBY_ENGINE) ? RUBY_ENGINE : 'ruby'
-            ruby += "-#{RUBY_VERSION}.#{RUBY_PATCHLEVEL}"
-
-            @env = [app, rails, ruby, RUBY_PLATFORM] * ','
           end
 
-          @env
-        end
+          def environment
+            unless defined? @env
+              app = "#{$1}.#{$2}" if File.directory?('.git') && `git branch -v` =~ /^\* (\S+)\s+(\S+)/
 
-        protected
-          HEADER = 'measurement,created_at,app,rails,ruby,platform'
+              rails = Rails::VERSION::STRING
+              if File.directory?('vendor/rails/.git')
+                Dir.chdir('vendor/rails') do
+                  rails += ".#{$1}.#{$2}" if `git branch -v` =~ /^\* (\S+)\s+(\S+)/
+                end
+              end
 
-          def with_output_file
-            fname = output_filename
+              ruby = defined?(RUBY_ENGINE) ? RUBY_ENGINE : 'ruby'
+              ruby += "-#{RUBY_VERSION}.#{RUBY_PATCHLEVEL}"
 
-            if new = !File.exist?(fname)
-              FileUtils.mkdir_p(File.dirname(fname))
+              @env = [app, rails, ruby, RUBY_PLATFORM] * ','
             end
 
-            File.open(fname, 'ab') do |file|
-              file.puts(HEADER) if new
-              yield file
-            end
+            @env
           end
 
-          def output_filename
-            "#{super}.csv"
-          end
-      end
+          protected
+            HEADER = 'measurement,created_at,app,rails,ruby,platform'
 
-      class Profiler < Performer
-        def initialize(*args)
-          super
-          @supported = @metric.measure_mode rescue false
-        end
+            def with_output_file
+              fname = output_filename
+
+              if new = !File.exist?(fname)
+                FileUtils.mkdir_p(File.dirname(fname))
+              end
 
-        def run
-          return unless @supported
+              File.open(fname, 'ab') do |file|
+                file.puts(HEADER) if new
+                yield file
+              end
+            end
 
-          RubyProf.measure_mode = @metric.measure_mode
-          RubyProf.start
-          RubyProf.pause
-          profile_options[:runs].to_i.times { run_test(@metric, :profile) }
-          @data = RubyProf.stop
-          @total = @data.threads.values.sum(0) { |method_infos| method_infos.sort.last.total_time }
+            def output_filename
+              "#{super}.csv"
+            end
         end
 
-        def report
-          if @supported
+        class Profiler < Performer
+          def initialize(*args)
             super
-          else
-            '%20s: unsupported' % @metric.name
+            @supported = @metric.measure_mode rescue false
           end
-        end
 
-        def record
-          return unless @supported
+          def run
+            return unless @supported
 
-          klasses = profile_options[:formats].map { |f| RubyProf.const_get("#{f.to_s.camelize}Printer") }.compact
+            RubyProf.measure_mode = @metric.measure_mode
+            RubyProf.start
+            RubyProf.pause
+            profile_options[:runs].to_i.times { run_test(@metric, :profile) }
+            @data = RubyProf.stop
+            @total = @data.threads.values.sum(0) { |method_infos| method_infos.sort.last.total_time }
+          end
 
-          klasses.each do |klass|
-            fname = output_filename(klass)
-            FileUtils.mkdir_p(File.dirname(fname))
-            File.open(fname, 'wb') do |file|
-              klass.new(@data).print(file, profile_options.slice(:min_percent))
+          def report
+            if @supported
+              super
+            else
+              '%20s: unsupported' % @metric.name
             end
           end
-        end
 
-        protected
-          def output_filename(printer_class)
-            suffix =
-              case printer_class.name.demodulize
-                when 'FlatPrinter'; 'flat.txt'
-                when 'GraphPrinter'; 'graph.txt'
-                when 'GraphHtmlPrinter'; 'graph.html'
-                when 'CallTreePrinter'; 'tree.txt'
-                else printer_class.name.sub(/Printer$/, '').underscore
-              end
+          def record
+            return unless @supported
+
+            klasses = profile_options[:formats].map { |f| RubyProf.const_get("#{f.to_s.camelize}Printer") }.compact
 
-            "#{super()}_#{suffix}"
+            klasses.each do |klass|
+              fname = output_filename(klass)
+              FileUtils.mkdir_p(File.dirname(fname))
+              File.open(fname, 'wb') do |file|
+                klass.new(@data).print(file, profile_options.slice(:min_percent))
+              end
+            end
           end
-      end
 
-      module Metrics
-        def self.[](name)
-          const_get(name.to_s.camelize)
-        rescue NameError
-          nil
+          protected
+            def output_filename(printer_class)
+              suffix =
+                case printer_class.name.demodulize
+                  when 'FlatPrinter'; 'flat.txt'
+                  when 'GraphPrinter'; 'graph.txt'
+                  when 'GraphHtmlPrinter'; 'graph.html'
+                  when 'CallTreePrinter'; 'tree.txt'
+                  else printer_class.name.sub(/Printer$/, '').underscore
+                end
+
+              "#{super()}_#{suffix}"
+            end
         end
 
-        class Base
-          attr_reader :total
-
-          def initialize
-            @total = 0
+        module Metrics
+          def self.[](name)
+            const_get(name.to_s.camelize)
+          rescue NameError
+            nil
           end
 
-          def name
-            @name ||= self.class.name.demodulize.underscore
-          end
+          class Base
+            attr_reader :total
 
-          def measure_mode
-            self.class::Mode
-          end
+            def initialize
+              @total = 0
+            end
 
-          def measure
-            0
-          end
+            def name
+              @name ||= self.class.name.demodulize.underscore
+            end
 
-          def benchmark
-            with_gc_stats do
-              before = measure
-              yield
-              @total += (measure - before)
+            def measure_mode
+              self.class::Mode
             end
-          end
 
-          def profile
-            RubyProf.resume
-            yield
-          ensure
-            RubyProf.pause
-          end
+            def measure
+              0
+            end
 
-          protected
-            if GC.respond_to?(:enable_stats)
-              def with_gc_stats
-                GC.enable_stats
-                yield
-              ensure
-                GC.disable_stats
-              end
-            elsif defined?(GC::Profiler)
-              def with_gc_stats
-                GC.start
-                GC.disable
-                GC::Profiler.enable
-                yield
-              ensure
-                GC::Profiler.disable
-                GC.enable
-              end
-            else
-              def with_gc_stats
+            def benchmark
+              with_gc_stats do
+                before = measure
                 yield
+                @total += (measure - before)
               end
             end
-        end
 
-        class Time < Base
-          def measure
-            ::Time.now.to_f
-          end
-
-          def format(measurement)
-            if measurement < 2
-              '%d ms' % (measurement * 1000)
-            else
-              '%.2f sec' % measurement
+            def profile
+              RubyProf.resume
+              yield
+            ensure
+              RubyProf.pause
             end
-          end
-        end
-
-        class ProcessTime < Time
-          Mode = RubyProf::PROCESS_TIME
-
-          def measure
-            RubyProf.measure_process_time
-          end
-        end
-
-        class WallTime < Time
-          Mode = RubyProf::WALL_TIME
 
-          def measure
-            RubyProf.measure_wall_time
+            protected
+              if GC.respond_to?(:enable_stats)
+                def with_gc_stats
+                  GC.enable_stats
+                  yield
+                ensure
+                  GC.disable_stats
+                end
+              elsif defined?(GC::Profiler)
+                def with_gc_stats
+                  GC.start
+                  GC.disable
+                  GC::Profiler.enable
+                  yield
+                ensure
+                  GC::Profiler.disable
+                  GC.enable
+                end
+              else
+                def with_gc_stats
+                  yield
+                end
+              end
           end
-        end
 
-        class CpuTime < Time
-          Mode = RubyProf::CPU_TIME if RubyProf.const_defined?(:CPU_TIME)
-
-          def initialize(*args)
-            # FIXME: yeah my CPU is 2.33 GHz
-            RubyProf.cpu_frequency = 2.33e9
-            super
-          end
+          class Time < Base
+            def measure
+              ::Time.now.to_f
+            end
 
-          def measure
-            RubyProf.measure_cpu_time
+            def format(measurement)
+              if measurement < 2
+                '%d ms' % (measurement * 1000)
+              else
+                '%.2f sec' % measurement
+              end
+            end
           end
-        end
 
-        class Memory < Base
-          Mode = RubyProf::MEMORY if RubyProf.const_defined?(:MEMORY)
+          class ProcessTime < Time
+            Mode = RubyProf::PROCESS_TIME
 
-          # ruby-prof wrapper
-          if RubyProf.respond_to?(:measure_memory)
             def measure
-              RubyProf.measure_memory / 1024.0
+              RubyProf.measure_process_time
             end
+          end
 
-          # Ruby 1.8 + railsbench patch
-          elsif GC.respond_to?(:allocated_size)
-            def measure
-              GC.allocated_size / 1024.0
-            end
+          class WallTime < Time
+            Mode = RubyProf::WALL_TIME
 
-          # Ruby 1.8 + lloyd patch
-          elsif GC.respond_to?(:heap_info)
             def measure
-              GC.heap_info['heap_current_memory'] / 1024.0
+              RubyProf.measure_wall_time
             end
+          end
 
-          # Ruby 1.9 with total_malloc_allocated_size patch
-          elsif GC.respond_to?(:malloc_total_allocated_size)
-            def measure
-              GC.total_malloc_allocated_size / 1024.0
-            end
+          class CpuTime < Time
+            Mode = RubyProf::CPU_TIME if RubyProf.const_defined?(:CPU_TIME)
 
-          # Ruby 1.9 unpatched
-          elsif GC.respond_to?(:malloc_allocated_size)
-            def measure
-              GC.malloc_allocated_size / 1024.0
+            def initialize(*args)
+              # FIXME: yeah my CPU is 2.33 GHz
+              RubyProf.cpu_frequency = 2.33e9
+              super
             end
 
-          # Ruby 1.9 + GC profiler patch
-          elsif defined?(GC::Profiler)
             def measure
-              GC.enable
-              GC.start
-              kb = GC::Profiler.data.last[:HEAP_USE_SIZE] / 1024.0
-              GC.disable
-              kb
+              RubyProf.measure_cpu_time
             end
           end
 
-          def format(measurement)
-            '%.2f KB' % measurement
-          end
-        end
+          class Memory < Base
+            Mode = RubyProf::MEMORY if RubyProf.const_defined?(:MEMORY)
 
-        class Objects < Base
-          Mode = RubyProf::ALLOCATIONS if RubyProf.const_defined?(:ALLOCATIONS)
+            # ruby-prof wrapper
+            if RubyProf.respond_to?(:measure_memory)
+              def measure
+                RubyProf.measure_memory / 1024.0
+              end
 
-          if RubyProf.respond_to?(:measure_allocations)
-            def measure
-              RubyProf.measure_allocations
-            end
+            # Ruby 1.8 + railsbench patch
+            elsif GC.respond_to?(:allocated_size)
+              def measure
+                GC.allocated_size / 1024.0
+              end
 
-          # Ruby 1.8 + railsbench patch
-          elsif ObjectSpace.respond_to?(:allocated_objects)
-            def measure
-              ObjectSpace.allocated_objects
+            # Ruby 1.8 + lloyd patch
+            elsif GC.respond_to?(:heap_info)
+              def measure
+                GC.heap_info['heap_current_memory'] / 1024.0
+              end
+
+            # Ruby 1.9 with total_malloc_allocated_size patch
+            elsif GC.respond_to?(:malloc_total_allocated_size)
+              def measure
+                GC.total_malloc_allocated_size / 1024.0
+              end
+
+            # Ruby 1.9 unpatched
+            elsif GC.respond_to?(:malloc_allocated_size)
+              def measure
+                GC.malloc_allocated_size / 1024.0
+              end
+
+            # Ruby 1.9 + GC profiler patch
+            elsif defined?(GC::Profiler)
+              def measure
+                GC.enable
+                GC.start
+                kb = GC::Profiler.data.last[:HEAP_USE_SIZE] / 1024.0
+                GC.disable
+                kb
+              end
             end
 
-          # Ruby 1.9 + GC profiler patch
-          elsif defined?(GC::Profiler)
-            def measure
-              GC.enable
-              GC.start
-              last = GC::Profiler.data.last
-              count = last[:HEAP_LIVE_OBJECTS] + last[:HEAP_FREE_OBJECTS]
-              GC.disable
-              count
+            def format(measurement)
+              '%.2f KB' % measurement
             end
           end
 
-          def format(measurement)
-            measurement.to_i.to_s
-          end
-        end
+          class Objects < Base
+            Mode = RubyProf::ALLOCATIONS if RubyProf.const_defined?(:ALLOCATIONS)
 
-        class GcRuns < Base
-          Mode = RubyProf::GC_RUNS if RubyProf.const_defined?(:GC_RUNS)
+            if RubyProf.respond_to?(:measure_allocations)
+              def measure
+                RubyProf.measure_allocations
+              end
 
-          if RubyProf.respond_to?(:measure_gc_runs)
-            def measure
-              RubyProf.measure_gc_runs
-            end
-          elsif GC.respond_to?(:collections)
-            def measure
-              GC.collections
-            end
-          elsif GC.respond_to?(:heap_info)
-            def measure
-              GC.heap_info['num_gc_passes']
+            # Ruby 1.8 + railsbench patch
+            elsif ObjectSpace.respond_to?(:allocated_objects)
+              def measure
+                ObjectSpace.allocated_objects
+              end
+
+            # Ruby 1.9 + GC profiler patch
+            elsif defined?(GC::Profiler)
+              def measure
+                GC.enable
+                GC.start
+                last = GC::Profiler.data.last
+                count = last[:HEAP_LIVE_OBJECTS] + last[:HEAP_FREE_OBJECTS]
+                GC.disable
+                count
+              end
             end
-          end
 
-          def format(measurement)
-            measurement.to_i.to_s
+            def format(measurement)
+              measurement.to_i.to_s
+            end
           end
-        end
 
-        class GcTime < Base
-          Mode = RubyProf::GC_TIME if RubyProf.const_defined?(:GC_TIME)
+          class GcRuns < Base
+            Mode = RubyProf::GC_RUNS if RubyProf.const_defined?(:GC_RUNS)
 
-          if RubyProf.respond_to?(:measure_gc_time)
-            def measure
-              RubyProf.measure_gc_time
+            if RubyProf.respond_to?(:measure_gc_runs)
+              def measure
+                RubyProf.measure_gc_runs
+              end
+            elsif GC.respond_to?(:collections)
+              def measure
+                GC.collections
+              end
+            elsif GC.respond_to?(:heap_info)
+              def measure
+                GC.heap_info['num_gc_passes']
+              end
             end
-          elsif GC.respond_to?(:time)
-            def measure
-              GC.time
+
+            def format(measurement)
+              measurement.to_i.to_s
             end
           end
 
-          def format(measurement)
-            '%d ms' % (measurement / 1000)
+          class GcTime < Base
+            Mode = RubyProf::GC_TIME if RubyProf.const_defined?(:GC_TIME)
+
+            if RubyProf.respond_to?(:measure_gc_time)
+              def measure
+                RubyProf.measure_gc_time
+              end
+            elsif GC.respond_to?(:time)
+              def measure
+                GC.time
+              end
+            end
+
+            def format(measurement)
+              '%d ms' % (measurement / 1000)
+            end
           end
         end
       end
     end
   end
-end
+rescue LoadError
+end
\ No newline at end of file
diff --git a/activesupport/test/autoload.rb b/activesupport/test/autoload.rb
new file mode 100644
index 0000000000..5d8026a9ca
--- /dev/null
+++ b/activesupport/test/autoload.rb
@@ -0,0 +1,80 @@
+require 'abstract_unit'
+
+class TestAutoloadModule < ActiveSupport::TestCase
+  include ActiveSupport::Testing::Isolation
+
+  module ::Fixtures
+    extend ActiveSupport::Autoload
+
+    module Autoload
+      extend ActiveSupport::Autoload
+    end
+  end
+
+  test "the autoload module works like normal autoload" do
+    module ::Fixtures::Autoload
+      autoload :SomeClass, "fixtures/autoload/some_class"
+    end
+
+    assert_nothing_raised { ::Fixtures::Autoload::SomeClass }
+  end
+
+  test "when specifying an :eager constant it still works like normal autoload by default" do
+    module ::Fixtures::Autoload
+      autoload :SomeClass, "fixtures/autoload/some_class"
+    end
+
+    assert !$LOADED_FEATURES.include?("fixtures/autoload/some_class.rb")
+    assert_nothing_raised { ::Fixtures::Autoload::SomeClass }
+  end
+
+  test ":eager constants can be triggered via ActiveSupport::Autoload.eager_autoload!" do
+    module ::Fixtures::Autoload
+      autoload :SomeClass, "fixtures/autoload/some_class"
+    end
+    ActiveSupport::Autoload.eager_autoload!
+    assert $LOADED_FEATURES.include?("fixtures/autoload/some_class.rb")
+    assert_nothing_raised { ::Fixtures::Autoload::SomeClass }
+  end
+
+  test "the location of autoloaded constants defaults to :name.underscore" do
+    module ::Fixtures::Autoload
+      autoload :SomeClass
+    end
+
+    assert !$LOADED_FEATURES.include?("fixtures/autoload/some_class.rb")
+    assert_nothing_raised { ::Fixtures::Autoload::SomeClass }
+  end
+
+  test "the location of :eager autoloaded constants defaults to :name.underscore" do
+    module ::Fixtures::Autoload
+      autoload :SomeClass
+    end
+
+    ActiveSupport::Autoload.eager_autoload!
+    assert $LOADED_FEATURES.include?("fixtures/autoload/some_class.rb")
+    assert_nothing_raised { ::Fixtures::Autoload::SomeClass }
+  end
+
+  test "a directory for a block of autoloads can be specified" do
+    module ::Fixtures
+      autoload_under "autoload" do
+        autoload :AnotherClass
+      end
+    end
+
+    assert !$LOADED_FEATURES.include?("fixtures/autoload/another_class.rb")
+    assert_nothing_raised { ::Fixtures::AnotherClass }
+  end
+
+  test "a path for a block of autoloads can be specified" do
+    module ::Fixtures
+      autoload_at "fixtures/autoload/another_class" do
+        autoload :AnotherClass
+      end
+    end
+
+    assert !$LOADED_FEATURES.include?("fixtures/autoload/another_class.rb")
+    assert_nothing_raised { ::Fixtures::AnotherClass }
+  end
+end
\ No newline at end of file
diff --git a/activesupport/test/fixtures/autoload/another_class.rb b/activesupport/test/fixtures/autoload/another_class.rb
new file mode 100644
index 0000000000..a240b3de41
--- /dev/null
+++ b/activesupport/test/fixtures/autoload/another_class.rb
@@ -0,0 +1,2 @@
+class Fixtures::AnotherClass
+end
\ No newline at end of file
diff --git a/activesupport/test/fixtures/autoload/some_class.rb b/activesupport/test/fixtures/autoload/some_class.rb
new file mode 100644
index 0000000000..13b3c73ef5
--- /dev/null
+++ b/activesupport/test/fixtures/autoload/some_class.rb
@@ -0,0 +1,2 @@
+class Fixtures::Autoload::SomeClass
+end
\ No newline at end of file