$dbw = $this->getMasterDB();
$count = 0; // affected rows
- if ( $this->claimTTL > 0 ) { // re-try stale jobs...
+ if ( !$dbw->lock( "jobqueue-recycle-{$this->type}", __METHOD__, 1 ) ) {
+ return $count; // already in progress
+ }
+
+ // Remove claims on jobs acquired for too long if enabled...
+ if ( $this->claimTTL > 0 ) {
$claimCutoff = $dbw->timestamp( $now - $this->claimTTL );
- // Reset job_token for these jobs so that other runners will pick them up.
- // Set the timestamp to the current time, as it is useful to now that the job
- // was already tried before.
- $dbw->update( 'job',
- array(
- 'job_token' => '',
- 'job_token_timestamp' => $dbw->timestamp( $now ) ), // time of release
+ // Get the IDs of jobs that have be claimed but not finished after too long.
+ // These jobs can be recycled into the queue by expiring the claim. Selecting
+ // the IDs first means that the UPDATE can be done by primary key (less deadlocks).
+ $res = $dbw->select( 'job', 'job_id',
array(
'job_cmd' => $this->type,
"job_token != {$dbw->addQuotes( '' )}", // was acquired
"job_token_timestamp < {$dbw->addQuotes( $claimCutoff )}", // stale
- "job_attempts < {$dbw->addQuotes( self::MAX_ATTEMPTS )}" ),
+ "job_attempts < {$dbw->addQuotes( self::MAX_ATTEMPTS )}" ), // retries left
__METHOD__
);
- $count += $dbw->affectedRows();
+ $ids = array_map( function( $o ) { return $o->job_id; }, iterator_to_array( $res ) );
+ if ( count( $ids ) ) {
+ // Reset job_token for these jobs so that other runners will pick them up.
+ // Set the timestamp to the current time, as it is useful to now that the job
+ // was already tried before (the timestamp becomes the "released" time).
+ $dbw->update( 'job',
+ array(
+ 'job_token' => '',
+ 'job_token_timestamp' => $dbw->timestamp( $now ) ), // time of release
+ array(
+ 'job_id' => $ids ),
+ __METHOD__
+ );
+ $count += $dbw->affectedRows();
+ }
}
- // Just destroy stale jobs...
+ // Just destroy any stale jobs...
$pruneCutoff = $dbw->timestamp( $now - self::MAX_AGE_PRUNE );
$conds = array(
'job_cmd' => $this->type,
if ( $this->claimTTL > 0 ) { // only prune jobs attempted too many times...
$conds[] = "job_attempts >= {$dbw->addQuotes( self::MAX_ATTEMPTS )}";
}
- $dbw->delete( 'job', $conds, __METHOD__ );
- $count += $dbw->affectedRows();
+ // Get the IDs of jobs that are considered stale and should be removed. Selecting
+ // the IDs first means that the UPDATE can be done by primary key (less deadlocks).
+ $res = $dbw->select( 'job', 'job_id', $conds, __METHOD__ );
+ $ids = array_map( function( $o ) { return $o->job_id; }, iterator_to_array( $res ) );
+ if ( count( $ids ) ) {
+ $dbw->delete( 'job', array( 'job_id' => $ids ), __METHOD__ );
+ $count += $dbw->affectedRows();
+ }
+
+ $dbw->unlock( "jobqueue-recycle-{$this->type}", __METHOD__ );
return $count;
}