Merge pull request #14735 from byroot/idempotent-counter-caches

Idempotent counter caches, fix concurrency issues with counter caches

1 files changed, 21 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/counter_cache.rb b/activerecord/lib/active_record/counter_cache.rb
index dcbdf75627..a5897edf03 100644
--- a/activerecord/lib/active_record/counter_cache.rb
+++ b/activerecord/lib/active_record/counter_cache.rb
@@ -118,5 +118,26 @@ module ActiveRecord
         update_counters(id, counter_name => -1)
       end
     end
+
+    protected
+
+      def actually_destroyed?
+        @_actually_destroyed
+      end
+
+      def clear_destroy_state
+        @_actually_destroyed = nil
+      end
+
+    private
+
+      def destroy_row
+        affected_rows = super
+
+        @_actually_destroyed = affected_rows > 0
+
+        affected_rows
+      end
+
   end
 end