make the @Updated flag atomic in the evented monitor

listen is calling us from its own thread, we need to synchronize reads and writes to this flag.
rails · Nov 21, 2015 · 49a5b40 · matthewd · Nov 21, 2015 · fxn
1 parent 96cc2e8
commit 49a5b40
Showing 1 changed file with 11 additions and 5 deletions.
diff --git a/activesupport/lib/active_support/file_evented_update_checker.rb b/activesupport/lib/active_support/file_evented_update_checker.rb
@@ -1,6 +1,8 @@
 require 'listen'
 require 'set'
 require 'pathname'
+require 'thread'
+require 'concurrent/atomic/atomic_boolean'
 
 module ActiveSupport
   class FileEventedUpdateChecker #:nodoc: all
@@ -14,22 +16,24 @@ def initialize(files, dirs = {}, &block)
       end
 
       @block   = block
-      @updated = false
+      @updated = Concurrent::AtomicBoolean.new(false)
       @lcsp    = @ph.longest_common_subpath(@dirs.keys)
 
       if (dtw = directories_to_watch).any?
         Listen.to(*dtw, &method(:changed)).start
       end
+
+      @mutex = Mutex.new
     end
 
     def updated?
-      @updated
+      @updated.true?
     end
 
     def execute
       @block.call
     ensure
-      @updated = false
+      @updated.make_false
 def execute 
   @last_watched   = watched 
   @last_update_at = updated_at(@last_watched) 
   @block.call 
 ensure 
   @watched = nil 
   @updated_at = nil 
 end 
 def execute 
   @last_watched   = watched 
   @last_update_at = updated_at(@last_watched) 
   @block.call 
 ensure 
   @watched = nil 
   @updated_at = nil 
 end 
     end
 
     def execute_if_updated
@@ -42,8 +46,10 @@ def execute_if_updated
     private
 
       def changed(modified, added, removed)
-        unless updated?
-          @updated = (modified + added + removed).any? { |f| watching?(f) }
+        @mutex.synchronize do
+          unless updated?
+            @updated.value = (modified + added + removed).any? { |f| watching?(f) }
+          end
         end
       end