Add Util::Subprocess#stop and Util::Subprocess#running?

lib/vagrant/util/subprocess.rb

@@ -35,6 +35,26 @@ module Vagrant
         @logger  = Log4r::Logger.new("vagrant::util::subprocess")
       end
 
+      # @return [TrueClass, FalseClass] subprocess is currently running
+      def running?
+        !!(@process && @process.alive?)
+      end
+
+      # Stop the subprocess if running
+      #
+      # @return [TrueClass] FalseClass] true if process was running and stopped
+      def stop
+        if @process && @process.alive?
+          @process.stop
+          true
+        else
+          false
+        end
+      end
+
+      # Start the process
+      #
+      # @return [Result]
       def execute
         # Get the timeout, if we have one
         timeout = @options[:timeout]
@@ -62,7 +82,7 @@ module Vagrant
 
         # Build the ChildProcess
         @logger.info("Starting process: #{@command.inspect}")
-        process = ChildProcess.build(*@command)
+        @process = process = ChildProcess.build(*@command)
 
         # Create the pipes so we can read the output in real time as
         # we execute the command.

test/unit/vagrant/util/subprocess_test.rb

@@ -47,4 +47,64 @@ describe Vagrant::Util::Subprocess do
       expect(result.stdout).to eq(data)
     end
   end
+
+  describe "#running?" do
+    context "when subprocess has not been started" do
+      it "should return false" do
+        sp = described_class.new("ls")
+        expect(sp.running?).to be_false
+      end
+    end
+    context "when subprocess has completed" do
+      it "should return false" do
+        sp = described_class.new("ls")
+        sp.execute
+        expect(sp.running?).to be_false
+      end
+    end
+    context "when subprocess is running" do
+      it "should return true" do
+        sp = described_class.new("sleep", "0.2")
+        thread = Thread.new{ sp.execute }
+        sleep(0.1)
+        expect(sp.running?).to be_true
+        thread.join
+      end
+    end
+  end
+
+  describe "#stop" do
+    context "when subprocess has not been started" do
+      it "should return false" do
+        sp = described_class.new("ls")
+        expect(sp.stop).to be_false
+      end
+    end
+
+    context "when subprocess has already completed" do
+      it "should return false" do
+        sp = described_class.new("ls")
+        sp.execute
+        expect(sp.stop).to be_false
+      end
+    end
+
+    context "when subprocess is running" do
+      let(:sp){ described_class.new("sleep", "1") }
+      it "should return true" do
+        thread = Thread.new{ sp.execute }
+        sleep(0.1)
+        expect(sp.stop).to be_true
+        thread.join
+      end
+
+      it "should stop the process" do
+        thread = Thread.new{ sp.execute }
+        sleep(0.1)
+        sp.stop
+        expect(sp.running?).to be_false
+        thread.join
+      end
+    end
+  end
 end