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Rewrite the background queue to not use locks for the insertion #6299

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Merged
dtdesign merged 1 commit into from
May 22, 2025
Merged

Rewrite the background queue to not use locks for the insertion #6299

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73 changes: 42 additions & 31 deletions wcfsetup/install/files/lib/system/background/BackgroundQueueHandler.class.php
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Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@
use wcf\data\user\User;
use wcf\system\background\job\AbstractBackgroundJob;
use wcf\system\background\job\AbstractUniqueBackgroundJob;
use wcf\system\database\util\PreparedStatementConditionBuilder;
use wcf\system\exception\ParentClassException;
use wcf\system\session\SessionHandler;
use wcf\system\SingletonFactory;
Expand Down Expand Up @@ -72,49 +73,59 @@ public function enqueueAt(AbstractBackgroundJob|array $jobs, int $time): void
$jobs = [$jobs];
}

$identifiers = [];
foreach ($jobs as $job) {
if (!($job instanceof AbstractBackgroundJob)) {
throw new ParentClassException(\get_class($job), AbstractBackgroundJob::class);
}

if ($job instanceof AbstractUniqueBackgroundJob) {
$identifiers[] = $job->identifier();
}
}

$committed = false;
try {
WCF::getDB()->beginTransaction();
$sql = "INSERT INTO wcf1_background_job
(job, time,identifier)
VALUES (?, ?, ?)";
if ($identifiers !== []) {
$conditions = new PreparedStatementConditionBuilder();
$conditions->add("identifier IN (?)", [$identifiers]);

$sql = "SELECT DISTINCT identifier
FROM wcf1_background_job
{$conditions}";
$statement = WCF::getDB()->prepare($sql);
$sql = "SELECT jobID
FROM wcf1_background_job
WHERE identifier = ?
FOR UPDATE";
$selectJobStatement = WCF::getDB()->prepare($sql);

foreach ($jobs as $job) {
$identifier = null;
if ($job instanceof AbstractUniqueBackgroundJob) {
// Check if the job is already in the queue
$selectJobStatement->execute([$job->identifier()]);
$jobID = $selectJobStatement->fetchSingleColumn();
if ($jobID !== false) {
continue;
$statement->execute($conditions->getParameters());
$existingJobs = $statement->fetchAll(\PDO::FETCH_COLUMN);

$jobs = \array_filter(
$jobs,
function ($job) use ($existingJobs) {
if ($job instanceof AbstractUniqueBackgroundJob && \in_array($job->identifier(), $existingJobs)) {
return false;
}
$identifier = $job->identifier();

return true;
}
);

$statement->execute([
\serialize($job),
$time,
$identifier
]);
if ($jobs === []) {
return;
}
WCF::getDB()->commitTransaction();
$committed = true;
} finally {
if (!$committed) {
WCF::getDB()->rollBackTransaction();
}

$sql = "INSERT INTO wcf1_background_job
(job, time, identifier)
VALUES (?, ?, ?)";
$statement = WCF::getDB()->prepare($sql);
foreach ($jobs as $job) {
$identifier = null;
if ($job instanceof AbstractUniqueBackgroundJob) {
$identifier = $job->identifier();
}

$statement->execute([
\serialize($job),
$time,
$identifier,
]);
}
}

Expand Down