[JobQueue] Fixed while loop in claimOldest() function.

Change-Id: I326b767c08944bcfde83c5e7f4a8339cecbab6d4

diff --git a/includes/job/JobQueueDB.php b/includes/job/JobQueueDB.php
index 4a9c47a..d7d2b19 100644 (file)
--- a/includes/job/JobQueueDB.php
+++ b/includes/job/JobQueueDB.php
@@ -186,7 +186,7 @@ class JobQueueDB extends JobQueue {
                // instead, but that either uses ORDER BY (in which case it deadlocks in MySQL) or is
                // not replication safe. Due to http://bugs.mysql.com/bug.php?id=6980, subqueries cannot
                // be used here with MySQL.
-               while ( true ) {
+               do {
                        $row = $dbw->selectRow( 'job', '*', // find a random job
                                array(
                                        'job_cmd'   => $this->type,
@@ -203,15 +203,13 @@ class JobQueueDB extends JobQueue {
                                );
                                // This might get raced out by another runner when claiming the previously
                                // selected row. The use of job_random should minimize this problem, however.
-                               if ( $dbw->affectedRows() ) {
-                                       break; // acquired
-                               } else {
+                               if ( !$dbw->affectedRows() ) {
                                        $row = false; // raced out
                                }
                        } else {
                                break; // nothing to do
                        }
-               }
+               } while ( !$row );
 
                return $row;
        }
@@ -226,7 +224,7 @@ class JobQueueDB extends JobQueue {
                $dbw  = $this->getMasterDB();
 
                $row = false; // the row acquired
-               while ( true ) {
+               do {
                        if ( $dbw->getType() === 'mysql' ) {
                                // Per http://bugs.mysql.com/bug.php?id=6980, we can't use subqueries on the
                                // same table being changed in an UPDATE query in MySQL (gives Error: 1093).
@@ -268,7 +266,7 @@ class JobQueueDB extends JobQueue {
                        } else {
                                break; // nothing to do
                        }
-               }
+               } while ( !$row );
 
                return $row;
        }