From: Aaron Schulz <aschulz@wikimedia.org>
Date: Fri, 2 Aug 2019 20:09:44 +0000 (-0400)
Subject: deferred: make DeferredUpdates::attemptUpdate() use callback owners for $fnameTrxOwner
X-Git-Tag: 1.34.0-rc.0~640^2
X-Git-Url: http://git.cyclocoop.org/%7B%24admin_url%7Dmembres/load.php?a=commitdiff_plain;h=182256c57293fc1ee5ff35e93632641aa1472066;p=lhc%2Fweb%2Fwiklou.git

deferred: make DeferredUpdates::attemptUpdate() use callback owners for $fnameTrxOwner

This only applies for instances of DeferrableCallback

Bug: T229694
Change-Id: I57fe351041c87342bd5774e333fcde4ae15059df
---

diff --git a/includes/deferred/DeferrableCallback.php b/includes/deferred/DeferrableCallback.php
index 2eb0d5dfa0..33961ed7bf 100644
--- a/includes/deferred/DeferrableCallback.php
+++ b/includes/deferred/DeferrableCallback.php
@@ -9,5 +9,5 @@ interface DeferrableCallback {
 	/**
 	 * @return string Originating method name
 	 */
-	function getOrigin();
+	public function getOrigin();
 }
diff --git a/includes/deferred/DeferredUpdates.php b/includes/deferred/DeferredUpdates.php
index d43ffbc975..3380364b6d 100644
--- a/includes/deferred/DeferredUpdates.php
+++ b/includes/deferred/DeferredUpdates.php
@@ -362,11 +362,16 @@ class DeferredUpdates {
 			$update->setTransactionTicket( $ticket );
 		}
 
-		$fnameTrxOwner = get_class( $update ) . '::doUpdate';
+		// Designate $update::doUpdate() as the write round owner
+		$fnameTrxOwner = ( $update instanceof DeferrableCallback )
+			? $update->getOrigin()
+			: get_class( $update ) . '::doUpdate';
+		// Determine whether the write round will be explicit or implicit
 		$useExplicitTrxRound = !(
 			$update instanceof TransactionRoundAwareUpdate &&
 			$update->getTransactionRoundRequirement() == $update::TRX_ROUND_ABSENT
 		);
+
 		// Flush any pending changes left over from an implicit transaction round
 		if ( $useExplicitTrxRound ) {
 			$lbFactory->beginMasterChanges( $fnameTrxOwner ); // new explicit round
diff --git a/tests/phpunit/includes/deferred/DeferredUpdatesTest.php b/tests/phpunit/includes/deferred/DeferredUpdatesTest.php
index b377c639f9..7e5ff84621 100644
--- a/tests/phpunit/includes/deferred/DeferredUpdatesTest.php
+++ b/tests/phpunit/includes/deferred/DeferredUpdatesTest.php
@@ -373,4 +373,27 @@ class DeferredUpdatesTest extends MediaWikiTestCase {
 		DeferredUpdates::tryOpportunisticExecute( 'run' );
 		$this->assertEquals( [ 'oti', 1, 2 ], $calls );
 	}
+
+	/**
+	 * @covers DeferredUpdates::attemptUpdate
+	 */
+	public function testCallbackUpdateRounds() {
+		$lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
+
+		$fname = __METHOD__;
+		$called = false;
+		DeferredUpdates::attemptUpdate(
+			new MWCallableUpdate(
+				function () use ( $lbFactory, $fname, &$called ) {
+					$lbFactory->flushReplicaSnapshots( $fname );
+					$lbFactory->commitMasterChanges( $fname );
+					$called = true;
+				},
+				$fname
+			),
+			$lbFactory
+		);
+
+		$this->assertTrue( $called, "Callback ran" );
+	}
 }