Merge "Fixes to prevent duplicate rows in ActiveUser cache"

diff --git a/includes/specials/SpecialActiveusers.php b/includes/specials/SpecialActiveusers.php
index d17b671..07e1be1 100644 (file)
--- a/includes/specials/SpecialActiveusers.php
+++ b/includes/specials/SpecialActiveusers.php
@@ -332,6 +332,8 @@ class SpecialActiveUsers extends SpecialPage {
         * @return int|bool UNIX timestamp the cache is now up-to-date as of (false on error)
         */
        protected static function doQueryCacheUpdate( DatabaseBase $dbw, $days, $window ) {
+               $dbw->startAtomic( __METHOD__ );
+
                $lockKey = wfWikiID() . '-activeusers';
                if ( !$dbw->lock( $lockKey, __METHOD__, 1 ) ) {
                        return false; // exclusive update (avoids duplicate entries)
@@ -343,6 +345,9 @@ class SpecialActiveUsers extends SpecialPage {
                        array( 'qci_type' => 'activeusers' )
                );
                $cTimeUnix = $cTime ? wfTimestamp( TS_UNIX, $cTime ) : 1;
+               // If a transaction was already started, it might have an old
+               // snapshot, so kludge the timestamp range a few seconds back.
+               $cTimeUnix -= 5;
 
                // Pick the date range to fetch from. This is normally from the last
                // update to till the present time, but has a limited window for sanity.
@@ -389,7 +394,10 @@ class SpecialActiveUsers extends SpecialPage {
                                        'qcc_type' => 'activeusers',
                                        'qcc_namespace' => NS_USER,
                                        'qcc_title' => array_keys( $names ) ),
-                               __METHOD__
+                               __METHOD__,
+                               // See the latest data (ignoring trx snapshot) to avoid
+                               // duplicates if this method was called in a transaction
+                               array( 'LOCK IN SHARE MODE' )
                        );
                        foreach ( $res as $row ) {
                                unset( $names[$row->user_name] );
@@ -426,6 +434,7 @@ class SpecialActiveUsers extends SpecialPage {
                );
 
                $dbw->unlock( $lockKey, __METHOD__ );
+               $dbw->endAtomic( __METHOD__ );
 
                return $eTimestamp;
        }