(PECL gearman <= 0.5.0)
GearmanJob::warning — Send a warning (deprecated)
$warning): boolSends a warning for this job while it is running.
注意:
This method has been replaced by GearmanJob::sendWarning() in the 0.6.0 release of the Gearman extension.
warningA warning messages.
成功时返回 true， 或者在失败时返回 false。