Merge branch 'all-tasks-are-multitasks' of https://github.com/michael…

…jbishop/rake into dashm

* 'all-tasks-are-multitasks' of https://github.com/michaeljbishop/rake:
  Added -m option which changes all tasks into multitasks

Conflicts:
	lib/rake/application.rb
	lib/rake/multi_task.rb

doc/command_line_usage.rdoc

@@ -49,6 +49,9 @@ Options are:
 [<tt>--libdir</tt> _directory_  (-I)]
     Add _directory_ to the list of directories searched for require.
 
+[<tt>--multitask</tt> (-m)]
+    Treat all tasks as multitasks. ('make/drake' semantics)
+
 [<tt>--nosearch</tt>  (-N)]
     Do not search for a Rakefile in parent directories.
 

lib/rake/application.rb

@@ -370,6 +370,9 @@ def standard_rake_options
           ['--libdir', '-I LIBDIR', "Include LIBDIR in the search path for required modules.",
             lambda { |value| $:.push(value) }
           ],
+          ['--multitask', '-m', "Treat all tasks as multitasks.",
+            lambda { |value| options.always_multitask = true }
+          ],
           ['--no-search', '--nosearch', '-N', "Do not search parent directories for the Rakefile.",
             lambda { |value| options.nosearch = true }
           ],
@@ -663,6 +666,6 @@ def rakefile_location(backtrace=caller)
 
   private
     FIXNUM_MAX = (2**(0.size * 8 - 2) - 1) # :nodoc:
-    
+
   end
 end

lib/rake/multi_task.rb

@@ -5,13 +5,8 @@ module Rake
   #
   class MultiTask < Task
     private
-    def invoke_prerequisites(args, invocation_chain)
-      futures = @prerequisites.collect do |p|
-        application.thread_pool.future(p) do |r|
-          application[r, @scope].invoke_with_call_chain(args, invocation_chain)
-        end
-      end
-      futures.each { |f| f.value }
+    def invoke_prerequisites(task_args, invocation_chain) # :nodoc:
+      invoke_prerequisites_concurrently(task_args, invocation_chain)
     end
   end
 

lib/rake/task.rb

@@ -179,10 +179,24 @@ def add_chain_to(exception, new_chain)
 
     # Invoke all the prerequisites of a task.
     def invoke_prerequisites(task_args, invocation_chain) # :nodoc:
-      prerequisite_tasks.each { |prereq|
-        prereq_args = task_args.new_scope(prereq.arg_names)
-        prereq.invoke_with_call_chain(prereq_args, invocation_chain)
-      }
+      if application.options.always_multitask
+        invoke_prerequisites_concurrently(task_args, invocation_chain)
+      else
+        prerequisite_tasks.each { |prereq|
+          prereq_args = task_args.new_scope(prereq.arg_names)
+          prereq.invoke_with_call_chain(prereq_args, invocation_chain)
+        }
+      end
+    end
+
+    # Invoke all the prerequisites of a task in parallel.
+    def invoke_prerequisites_concurrently(args, invocation_chain) # :nodoc:
+      futures = @prerequisites.collect do |p|
+        application.thread_pool.future(p) do |r|
+          application[r, @scope].invoke_with_call_chain(args, invocation_chain)
+        end
+      end
+      futures.each { |f| f.call }
     end
 
     # Format the trace flags for display.

test/test_rake_application_options.rb

@@ -34,6 +34,7 @@ def test_default_options
     assert_nil opts.dryrun
     assert_nil opts.ignore_system
     assert_nil opts.load_system
+    assert_nil opts.always_multitask
     assert_nil opts.nosearch
     assert_equal ['rakelib'], opts.rakelib
     assert_nil opts.show_prereqs
@@ -132,6 +133,12 @@ def test_libdir
     $:.delete('xx')
   end
 
+  def test_multitask
+    flags('--multitask', '-m') do |opts|
+      assert_equal opts.always_multitask, true
+    end
+  end
+
   def test_rakefile
     flags(['--rakefile', 'RF'], ['--rakefile=RF'], ['-f', 'RF'], ['-fRF']) do |opts|
       assert_equal ['RF'], @app.instance_eval { @rakefiles }

test/test_rake_task.rb

@@ -241,6 +241,38 @@ def c.timestamp() Time.now + 5 end
     assert_in_delta now + 10, a.timestamp, 0.1, 'computer too slow?'
   end
 
+  def test_always_multitask
+    mx = Mutex.new
+    result = ""
+
+    t_a = task(:a) do |t|
+      sleep 0.02
+      mx.synchronize{ result << t.name }
+    end
+
+    t_b = task(:b) do |t|
+      mx.synchronize{ result << t.name }
+    end
+
+    t_c = task(:c => [:a,:b]) do |t|
+      mx.synchronize{ result << t.name }
+    end
+
+    t_c.invoke
+
+    # task should always run in order
+    assert_equal 'abc', result
+
+    [t_a, t_b, t_c].each { |t| t.reenable }
+    result.clear
+
+    Rake.application.options.always_multitask = true
+    t_c.invoke
+
+    # with multitask, task 'b' should grab the mutex first
+    assert_equal 'bac', result
+  end
+
   def test_investigation_output
     t1 = task(:t1 => [:t2, :t3]) { |t| runlist << t.name; 3321 }
     task(:t2)