This commit changes the way that WC_Background_Updater::task() calls the database update callbacks and adds the WC_Background_Updater instance as the first parameter to the callbacks. This is used in wc_update_350_order_customer_id() (36b6bd79c0/includes/wc-update-functions.php (L1870)) to monitor memory usage while the function is running. This change was intended to ship with PR #17895 (see commit c77b2f20f4) but was accidentaly removed when merging commit 083c994732 from another PR.
Fixes#20718
Turns out WP_Background_Process uses an arbitrary value of 20 seconds of wall clock time to measure PHP "time limit" (b0617a13c4/includes/libraries/wp-background-process.php (L385)) instead of cpu time which apparently it is not easy to measure in PHP. Since system calls (like database calls) are not included in the PHP maximum execution time, 20 seconds of wall clock is often way less than PHP time limit.
Thus, this commit removes the call to WP_Background_Process::time_exceeded() while running the function to migrate the post meta _customer_user to the field post_author. If the script times out, WP_Background_Process will restart it.
This change makes it possible to monitor resource usage inside each of the database update functions. Useful when doing resource intensive updates to stop the execution and requeue before the execution is aborted.
Rodrigo Primo
Mike Jolley
Claudio Sanches
Jon Surrell
Shiva Poudel