Add file mutex util module

lib/vagrant/action/builtin/box_add.rb

@@ -6,6 +6,7 @@ require "uri"
 require "vagrant/box_metadata"
 require "vagrant/util/downloader"
 require "vagrant/util/file_checksum"
+require "vagrant/util/file_mutex"
 require "vagrant/util/platform"
 
 module Vagrant
@@ -22,10 +23,6 @@ module Vagrant
         # file already exists.
         RESUME_DELAY = 24 * 60 * 60
 
-        # When a box file is being downloaded, identify the download is in progress
-        # by Vagrant with a mutex file named <box file destination>.<MUTEX_SUFFIX>
-        MUTEX_SUFFIX = ".lock"
-
         def initialize(app, env)
           @app    = app
           @logger = Log4r::Logger.new("vagrant::action::builtin::box_add")
@@ -482,23 +479,22 @@ module Vagrant
             end
           end
 
-          mutex_path = d.destination + MUTEX_SUFFIX
-          if File.file?(mutex_path)
-            raise Errors::DownloadAlreadyInProgress,
-              dest_path: d.destination,
-              lock_file_path: mutex_path
-          end
-
           begin
-            File.write(mutex_path, "")
+            mutex_path = d.destination + ".lock"
+            Util::FileMutex.new(mutex_path).with_lock do
+              begin
                 d.download!
               rescue Errors::DownloaderInterrupted
                 # The downloader was interrupted, so just return, because that
                 # means we were interrupted as well.
                 @download_interrupted = true
                 env[:ui].info(I18n.t("vagrant.actions.box.download.interrupted"))
-          ensure
+              end
-            File.delete(mutex_path)
+            end
+          rescue Errors::VagrantLocked
+            raise Errors::DownloadAlreadyInProgress,
+              dest_path: d.destination,
+              lock_file_path: mutex_path
           end
 
           Pathname.new(d.destination)

lib/vagrant/errors.rb

@@ -924,6 +924,10 @@ module Vagrant
       error_key(:uploader_interrupted)
     end
 
+    class VagrantLocked < VagrantError
+      error_key(:vagrant_locked)
+    end
+
     class VagrantInterrupt < VagrantError
       error_key(:interrupted)
     end

lib/vagrant/util.rb

@@ -20,6 +20,7 @@ module Vagrant
     autoload :Experimental,              'vagrant/util/experimental'
     autoload :FileChecksum,              'vagrant/util/file_checksum'
     autoload :FileMode,                  'vagrant/util/file_mode'
+    autoload :FileMutex,                 'vagrant/util/file_mutex'
     autoload :GuestHosts,                'vagrant/util/guest_hosts'
     autoload :GuestInspection,           'vagrant/util/guest_inspection'
     autoload :HashWithIndifferentAccess, 'vagrant/util/hash_with_indifferent_access'

lib/vagrant/util/file_mutex.rb

@@ -0,0 +1,29 @@
+module Vagrant
+  module Util
+    class FileMutex
+      def initialize(mutex_path)
+        @mutex_path = mutex_path
+      end
+
+      def with_lock(&block)
+        lock
+        block.call
+      ensure
+        unlock
+      end
+
+      def lock
+        if File.file?(@mutex_path)
+          raise Errors::VagrantLocked,
+            lock_file_path: @mutex_path
+        end
+        
+        File.write(@mutex_path, "")
+      end
+
+      def unlock
+        File.delete(@mutex_path)
+      end
+    end
+  end
+end

templates/locales/en.yml

@@ -1675,6 +1675,11 @@ en:
       uploader_interrupted: |-
         The upload was interrupted by an external signal. It did not
         complete.
+      vagrant_locked: |-
+        The requested Vagrant action is locked. This may be caused
+        by other Vagrant processes attempting to do a similar action.
+
+        Lock file path: %{lock_file_path}
       vagrantfile_exists: |-
         `Vagrantfile` already exists in this directory. Remove it before
         running `vagrant init`.