Merge "rdbms: add IDatabase::lockForUpdate() convenience method"

[lhc/web/wiklou.git] / includes / Category.php

diff --git a/includes/Category.php b/includes/Category.php
index 46b86d8..f8ac8ae 100644 (file)
--- a/includes/Category.php
+++ b/includes/Category.php
@@ -48,7 +48,7 @@ class Category {
 
        /**
         * Set up all member variables using a database query.
-        * @param int $mode
+        * @param int $mode One of (Category::LOAD_ONLY, Category::LAZY_INIT_ROW)
         * @throws MWException
         * @return bool True on success, false on failure.
         */
@@ -171,7 +171,7 @@ class Category {
         *   fields are null, the resulting Category object will represent an empty
         *   category if a title object was given. If the fields are null and no
         *   title was given, this method fails and returns false.
-        * @param Title $title Optional title object for the category represented by
+        * @param Title|null $title Optional title object for the category represented by
         *   the given row. May be provided if it is already known, to avoid having
         *   to re-create a title object later.
         * @return Category|false
@@ -335,6 +335,10 @@ class Category {
 
                $dbw->startAtomic( __METHOD__ );
 
+               // Lock the `category` row before locking `categorylinks` rows to try
+               // to avoid deadlocks with LinksDeletionUpdate (T195397)
+               $dbw->lockForUpdate( 'category', [ 'cat_title' => $this->mName ], __METHOD__ );
+
                // Lock all the `categorylinks` records and gaps for this category;
                // this is a separate query due to postgres/oracle limitations
                $dbw->selectRowCount(