From 0622fbb077eba5df2bacbb24b03cf3ff7939c417 Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aschulz@wikimedia.org>
Date: Thu, 1 Sep 2016 09:43:01 -0700
Subject: [PATCH] Set "run when DBs idle" DeferredUpdates logic in Maintenance

* This is a more robust version of the one inside
  DeferredUpdates (checking all DBs), which will be
  replaced in a later commit.
* Make sure the listener is restored when the LB gets
  torn down in tests. Also, it should respect the
  $wgCommandLineMode value as tests can change it.

Change-Id: I1e3faa5a058df44e2d27ab5ac185930867eb68ac
---
 maintenance/Maintenance.php         | 29 ++++++++++++++++++++++++++++-
 tests/phpunit/MediaWikiTestCase.php |  5 +++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/maintenance/Maintenance.php b/maintenance/Maintenance.php
index 343687e61c..698fd9a4d0 100644
--- a/maintenance/Maintenance.php
+++ b/maintenance/Maintenance.php
@@ -554,11 +554,38 @@ abstract class Maintenance {
 	 * @since 1.28
 	 */
 	public function setTriggers() {
+		$lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
+		self::setLBFactoryTriggers( $lbFactory );
+	}
+
+	/**
+	 * @param LBFactory $LBFactory
+	 * @since 1.28
+	 */
+	public static function setLBFactoryTriggers( LBFactory $LBFactory ) {
 		// Hook into period lag checks which often happen in long-running scripts
 		$lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
 		$lbFactory->setWaitForReplicationListener(
 			__METHOD__,
-			[ 'DeferredUpdates', 'tryOpportunisticExecute' ]
+			function () {
+				global $wgCommandLineMode;
+				// Check config in case of JobRunner and unit tests
+				if ( $wgCommandLineMode ) {
+					DeferredUpdates::tryOpportunisticExecute( 'run' );
+				}
+			}
+		);
+		// Check for other windows to run them. A script may read or do a few writes
+		// to the master but mostly be writing to something else, like a file store.
+		$lbFactory->getMainLB()->setTransactionListener(
+			__METHOD__,
+			function ( $trigger ) {
+				global $wgCommandLineMode;
+				// Check config in case of JobRunner and unit tests
+				if ( $wgCommandLineMode && $trigger === IDatabase::TRIGGER_COMMIT ) {
+					DeferredUpdates::tryOpportunisticExecute( 'run' );
+				}
+			}
 		);
 	}
 
diff --git a/tests/phpunit/MediaWikiTestCase.php b/tests/phpunit/MediaWikiTestCase.php
index 27f1454dca..541ac11518 100644
--- a/tests/phpunit/MediaWikiTestCase.php
+++ b/tests/phpunit/MediaWikiTestCase.php
@@ -482,6 +482,11 @@ abstract class MediaWikiTestCase extends PHPUnit_Framework_TestCase {
 		DeferredUpdates::clearPendingUpdates();
 		ObjectCache::getMainWANInstance()->clearProcessCache();
 
+		// XXX: reset maintenance triggers
+		// Hook into period lag checks which often happen in long-running scripts
+		$lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
+		Maintenance::setLBFactoryTriggers( $lbFactory );
+
 		ob_start( 'MediaWikiTestCase::wfResetOutputBuffersBarrier' );
 	}
 
-- 
2.20.1