Fix processing of events when build finished.

This solves Pipelines in `running` after all stages do finish.

app/models/ci/pipeline.rb

@@ -241,7 +241,8 @@ module Ci
     end
 
     def build_updated
-      case latest_builds_status
+      with_lock do
+        case reload.latest_builds_status
         when 'pending' then enqueue
         when 'running' then run
         when 'success' then succeed
@@ -250,6 +251,7 @@ module Ci
         when 'skipped' then skip
         end
       end
+    end
 
     def predefined_variables
       [

app/models/commit_status.rb

@@ -69,15 +69,15 @@ class CommitStatus < ActiveRecord::Base
       commit_status.update_attributes finished_at: Time.now
     end
 
-    after_transition do |commit_status, transition|
-      commit_status.pipeline.try(:build_updated) unless transition.loopback?
-    end
-
     after_transition any => [:success, :failed, :canceled] do |commit_status|
       commit_status.pipeline.try(:process!)
       true
     end
 
+    after_transition do |commit_status, transition|
+      commit_status.pipeline.try(:build_updated) unless transition.loopback?
+    end
+
     after_transition [:created, :pending, :running] => :success do |commit_status|
       MergeRequests::MergeWhenBuildSucceedsService.new(commit_status.pipeline.project, nil).trigger(commit_status)
     end