Signal trapping for SIGINT waits for busy signal to go low

lib/vagrant/actions/import.rb

@@ -4,8 +4,10 @@ module Vagrant
       def execute!
         @vm.invoke_callback(:before_import)
 
-        logger.info "Importing base VM (#{Vagrant.config[:vm][:base]})..."
-        @vm.vm = VirtualBox::VM.import(File.expand_path(Vagrant.config[:vm][:base]))
+        Busy.busy do
+          logger.info "Importing base VM (#{Vagrant.config[:vm][:base]})..."
+          @vm.vm = VirtualBox::VM.import(File.expand_path(Vagrant.config[:vm][:base]))
+        end
 
         @vm.invoke_callback(:after_import)
       end

lib/vagrant/busy.rb

@@ -8,6 +8,8 @@ module Vagrant
   end
 
   class Busy
+    extend Vagrant::Util
+
     @@busy = false
     @@mutex = Mutex.new
 
@@ -23,15 +25,34 @@ module Vagrant
       def busy(&block)
         @@mutex.synchronize do
           begin
+            Signal.trap("INT") { wait_for_not_busy }
             Busy.busy = true
-            yield
+            runner = Thread.new(block) { block.call }
+            runner.join
           ensure
             # In the case an exception is thrown, make sure we restore
             # busy back to some sane state.
             Busy.busy = false
+
+            # And restore the INT trap to the default
+            Signal.trap("INT", "DEFAULT")
           end
         end
       end
+
+      def wait_for_not_busy(sleeptime=5)
+        Thread.new do
+          # Wait while the app is busy
+          loop do
+            break unless busy?
+            logger.info "Waiting for vagrant to clean itself up..."
+            sleep sleeptime
+          end
+
+          # Exit out of the entire script
+          exit
+        end
+      end
     end
   end
 end

test/vagrant/actions/import_test.rb

@@ -7,6 +7,11 @@ class ImportActionTest < Test::Unit::TestCase
     VirtualBox::VM.stubs(:import)
   end
 
+  should "run in a busy block" do
+    Vagrant::Busy.expects(:busy).once
+    @import.execute!
+  end
+
   should "invoke before/after callbacks around the import" do
     callback_seq = sequence("callback_seq")
     @mock_vm.expects(:invoke_callback).with(:before_import).once.in_sequence(callback_seq)

test/vagrant/busy_test.rb

@@ -1,6 +1,10 @@
 require File.join(File.dirname(__FILE__), '..', 'test_helper')
 
 class BusyTest < Test::Unit::TestCase
+  context "waiting for not busy" do
+    # TODO: Need to test this method
+  end
+
   context "during an action in a busy block" do
     should "report as busy" do
       Vagrant.busy do
@@ -33,5 +37,21 @@ class BusyTest < Test::Unit::TestCase
       # While the above thread is executing vagrant should be busy
       assert Vagrant.busy?
     end
+
+    should "run the action in a new thread" do
+      runner_thread = nil
+      Vagrant.busy do
+        runner_thread = Thread.current
+      end
+
+      assert_not_equal Thread.current, runner_thread
+    end
+
+    should "trap INT" do
+      trap_seq = sequence("trap_seq")
+      Signal.expects(:trap).with("INT", anything).once.in_sequence(trap_seq)
+      Signal.expects(:trap).with("INT", "DEFAULT").once.in_sequence(trap_seq)
+      Vagrant.busy do; end
+    end
   end
 end