Prefer that enqueueable post-send updates are run immediately

If the user is not waiting at this point, so there is not much
reason to enqueue a job over just doing the work now. Running
the update now gives more immediate results however.

This has the effect of  making LinksUpdate run post-send for
forward link updates, since the addUpdate() call in WikiPage uses
the default POSTSEND mode. These updates used to be synchronous
in the past, before proper post-send update support. With post-send
updates, there is not much benefit to using the job queue here.

If post-send updates are not supported, this will continue to
use the job queue.

If a caller needs such updates to enqueue post-send to avoid DB
updates on HTTP GET or if the update is too big to run outside of
JobRunner, it can always just use JobQueueGroup::lazyPush() with
a direct job object or JobSpecification.

Change-Id: Ibc4b1e17538cc8b1fba7d13759e1ebb83abed869

diff --git a/includes/MediaWiki.php b/includes/MediaWiki.php
index 7b59ee9..0f40c19 100644 (file)
--- a/includes/MediaWiki.php
+++ b/includes/MediaWiki.php
@@ -712,10 +712,11 @@ class MediaWiki {
                        MWExceptionHandler::rollbackMasterChangesAndLog( $e );
                }
 
+               $blocksHttpClient = true;
                // Defer everything else if possible...
-               $callback = function () use ( $mode ) {
+               $callback = function () use ( $mode, &$blocksHttpClient ) {
                        try {
-                               $this->restInPeace( $mode );
+                               $this->restInPeace( $mode, $blocksHttpClient );
                        } catch ( Exception $e ) {
                                // If this is post-send, then displaying errors can cause broken HTML
                                MWExceptionHandler::rollbackMasterChangesAndLog( $e );
@@ -725,9 +726,11 @@ class MediaWiki {
                if ( function_exists( 'register_postsend_function' ) ) {
                        // https://github.com/facebook/hhvm/issues/1230
                        register_postsend_function( $callback );
+                       $blocksHttpClient = false;
                } else {
                        if ( function_exists( 'fastcgi_finish_request' ) ) {
                                fastcgi_finish_request();
+                               $blocksHttpClient = false;
                        } else {
                                // Either all DB and deferred updates should happen or none.
                                // The latter should not be cancelled due to client disconnect.
@@ -870,8 +873,9 @@ class MediaWiki {
        /**
         * Ends this task peacefully
         * @param string $mode Use 'fast' to always skip job running
+        * @param bool $blocksHttpClient Whether this blocks an HTTP response to a client
         */
-       public function restInPeace( $mode = 'fast' ) {
+       public function restInPeace( $mode = 'fast', $blocksHttpClient = true ) {
                $lbFactory = MediaWikiServices::getInstance()->getDBLoadBalancerFactory();
                // Assure deferred updates are not in the main transaction
                $lbFactory->commitMasterChanges( __METHOD__ );
@@ -887,8 +891,8 @@ class MediaWiki {
                // Important: this must be the last deferred update added (T100085, T154425)
                DeferredUpdates::addCallableUpdate( [ JobQueueGroup::class, 'pushLazyJobs' ] );
 
-               // Do any deferred jobs
-               DeferredUpdates::doUpdates( 'enqueue' );
+               // Do any deferred jobs; preferring to run them now if a client will not wait on them
+               DeferredUpdates::doUpdates( $blocksHttpClient ? 'enqueue' : 'run' );
 
                // Now that everything specific to this request is done,
                // try to occasionally run jobs (if enabled) from the queues