1 files changed, 76 insertions, 0 deletions
diff --git a/includes/jobqueue/jobs/NullJob.php b/includes/jobqueue/jobs/NullJob.php
new file mode 100644
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--- /dev/null
+++ b/includes/jobqueue/jobs/NullJob.php
@@ -0,0 +1,76 @@
+<?php
+/**
+ * Degenerate job that does nothing.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Cache
+ */
+
+/**
+ * Degenerate job that does nothing, but can optionally replace itself
+ * in the queue and/or sleep for a brief time period. These can be used
+ * to represent "no-op" jobs or test lock contention and performance.
+ *
+ * @par Example:
+ * Inserting a null job in the configured job queue:
+ * @code
+ * $ php maintenance/eval.php
+ * > $queue = JobQueueGroup::singleton();
+ * > $job = new NullJob( Title::newMainPage(), array( 'lives' => 10 ) );
+ * > $queue->push( $job );
+ * @endcode
+ * You can then confirm the job has been enqueued by using the showJobs.php
+ * maintenance utility:
+ * @code
+ * $ php maintenance/showJobs.php --group
+ * null: 1 queue; 0 claimed (0 active, 0 abandoned)
+ * $
+ * @endcode
+ *
+ * @ingroup JobQueue
+ */
+class NullJob extends Job {
+	/**
+	 * @param Title $title
+	 * @param array $params Job parameters (lives, usleep)
+	 */
+	function __construct( $title, $params ) {
+		parent::__construct( 'null', $title, $params );
+		if ( !isset( $this->params['lives'] ) ) {
+			$this->params['lives'] = 1;
+		}
+		if ( !isset( $this->params['usleep'] ) ) {
+			$this->params['usleep'] = 0;
+		}
+		$this->removeDuplicates = !empty( $this->params['removeDuplicates'] );
+	}
+
+	public function run() {
+		if ( $this->params['usleep'] > 0 ) {
+			usleep( $this->params['usleep'] );
+		}
+		if ( $this->params['lives'] > 1 ) {
+			$params = $this->params;
+			$params['lives']--;
+			$job = new self( $this->title, $params );
+			JobQueueGroup::singleton()->push( $job );
+		}
+
+		return true;
+	}
+}