Merge "SpecialMyLanguage: Get content language from service"

[lhc/web/wiklou.git] / includes / deferred / DeferredUpdates.php

diff --git a/includes/deferred/DeferredUpdates.php b/includes/deferred/DeferredUpdates.php
index 9b25d53..8543c4b 100644 (file)
--- a/includes/deferred/DeferredUpdates.php
+++ b/includes/deferred/DeferredUpdates.php
@@ -36,11 +36,14 @@ use Wikimedia\Rdbms\LoadBalancer;
  * Updates that work through this system will be more likely to complete by the time the client
  * makes their next request after this one than with the JobQueue system.
  *
- * In CLI mode, updates run immediately if no DB writes are pending. Otherwise, they run when:
- *   - a) Any waitForReplication() call if no writes are pending on any DB
- *   - b) A commit happens on Maintenance::getDB( DB_MASTER ) if no writes are pending on any DB
- *   - c) EnqueueableDataUpdate tasks may enqueue on commit of Maintenance::getDB( DB_MASTER )
- *   - d) At the completion of Maintenance::execute()
+ * In CLI mode, deferred updates will run:
+ *   - a) During DeferredUpdates::addUpdate if no LBFactory DB handles have writes pending
+ *   - b) On commit of an LBFactory DB handle if no other such handles have writes pending
+ *   - c) During an LBFactory::waitForReplication call if no LBFactory DBs have writes pending
+ *   - d) When the queue is large and an LBFactory DB handle commits (EnqueueableDataUpdate only)
+ *   - e) At the completion of Maintenance::execute()
+ *
+ * @see Maintenance::setLBFactoryTriggers
  *
  * When updates are deferred, they go into one two FIFO "top-queues" (one for pre-send and one
  * for post-send). Updates enqueued *during* doUpdate() of a "top" update go into the "sub-queue"
@@ -206,23 +209,29 @@ class DeferredUpdates {
                        foreach ( $updatesByType as $updatesForType ) {
                                foreach ( $updatesForType as $update ) {
                                        self::$executeContext = [ 'stage' => $stage, 'subqueue' => [] ];
-                                       /** @var DeferrableUpdate $update */
-                                       $guiError = self::runUpdate( $update, $lbFactory, $mode, $stage );
-                                       $reportableError = $reportableError ?: $guiError;
-                                       // Do the subqueue updates for $update until there are none
-                                       while ( self::$executeContext['subqueue'] ) {
-                                               $subUpdate = reset( self::$executeContext['subqueue'] );
-                                               $firstKey = key( self::$executeContext['subqueue'] );
-                                               unset( self::$executeContext['subqueue'][$firstKey] );
-
-                                               if ( $subUpdate instanceof DataUpdate ) {
-                                                       $subUpdate->setTransactionTicket( $ticket );
-                                               }
-
-                                               $guiError = self::runUpdate( $subUpdate, $lbFactory, $mode, $stage );
+                                       try {
+                                               /** @var DeferrableUpdate $update */
+                                               $guiError = self::runUpdate( $update, $lbFactory, $mode, $stage );
                                                $reportableError = $reportableError ?: $guiError;
+                                               // Do the subqueue updates for $update until there are none
+                                               while ( self::$executeContext['subqueue'] ) {
+                                                       $subUpdate = reset( self::$executeContext['subqueue'] );
+                                                       $firstKey = key( self::$executeContext['subqueue'] );
+                                                       unset( self::$executeContext['subqueue'][$firstKey] );
+
+                                                       if ( $subUpdate instanceof DataUpdate ) {
+                                                               $subUpdate->setTransactionTicket( $ticket );
+                                                       }
+
+                                                       $guiError = self::runUpdate( $subUpdate, $lbFactory, $mode, $stage );
+                                                       $reportableError = $reportableError ?: $guiError;
+                                               }
+                                       } finally {
+                                               // Make sure we always clean up the context.
+                                               // Losing updates while rewinding the stack is acceptable,
+                                               // losing updates that are added later is not.
+                                               self::$executeContext = null;
                                        }
-                                       self::$executeContext = null;
                                }
                        }
 
@@ -265,6 +274,12 @@ class DeferredUpdates {
                                $guiError = $e;
                        }
                        MWExceptionHandler::rollbackMasterChangesAndLog( $e );
+
+                       // VW-style hack to work around T190178, so we can make sure
+                       // PageMetaDataUpdater doesn't throw exceptions.
+                       if ( defined( 'MW_PHPUNIT_TEST' ) ) {
+                               throw $e;
+                       }
                }
 
                return $guiError;
@@ -273,8 +288,9 @@ class DeferredUpdates {
        /**
         * Run all deferred updates immediately if there are no DB writes active
         *
-        * If $mode is 'run' but there are busy databates, EnqueueableDataUpdate
-        * tasks will be enqueued anyway for the sake of progress.
+        * If there are many deferred updates pending, $mode is 'run', and there
+        * are still busy LBFactory database handles, then any EnqueueableDataUpdate
+        * tasks might be enqueued as jobs to be executed later.
         *
         * @param string $mode Use "enqueue" to use the job queue when possible
         * @return bool Whether updates were allowed to run
@@ -361,7 +377,7 @@ class DeferredUpdates {
         */
        private static function areDatabaseTransactionsActive() {
                $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
-               if ( $lbFactory->hasTransactionRound() ) {
+               if ( $lbFactory->hasTransactionRound() || !$lbFactory->isReadyForRoundOperations() ) {
                        return true;
                }