PHP Warning: flock() expects parameter 1 to be resource

Hi,

The new version dropped the use of sessions and it’s using a file for the processing queue, could you please check that the plugin is allowed to create a file in the uploads folder? There should be a file called .shortpixel-q-1.

Yes, it was permission problem. Fixed.
p.s. It would be nice if your plugin could check permission and warn the user in case of problems.

Indeed, that’s what I’ll do in the next version. ?? Thanks for your feed-back!

I just ran into this problem as well… it was causing ongoing 99.9% CPU usage! We have a remote script that runs wp-cli (“wp plugin list”), and that was what was triggering it. When I tested it myself on the command line, this warning just repeated indefinitely:

Warning: flock() expects parameter 1 to be resource, boolean given in /home/123456.cloudwaysapps.com/asdfasdf/public_html/wp-content/plugins/shortpixel-image-optimiser/class/shortpixel_queue.php on line 67
PHP Warning:  flock() expects parameter 1 to be resource, boolean given in /home/123456.cloudwaysapps.com/asdfasdf/public_html/wp-content/plugins/shortpixel-image-optimiser/class/shortpixel_queue.php on line 67

Resetting permissions on the server solved the issue.

Hope the new fix is coming soon so others don’t have to spend hours tracking this down, too.

Just a quick update: the version 4.8.6 does warn about the permissions problem and also doesn’t load the CPU anymore.