Cleans up hung routines of Task Scheduler WordPress plugin.

task-scheduler-hung-routine-cleaner.php

<?php
/** 
 *  Plugin Name:    Task Scheduler - Hung Routine Cleaner
 *  Description:    Cleans up hung routines.
 *  Author:         Michael Uno
 *  Version:        1.0.0
 */

class TaskSchedulerHungRoutineCleaner {

    public $iElapsedTime    = 1800; // seconds - 30 minutes
    public $iCheckInterval  = 43200; // seconds - 12 hours
    
    private $___sPeriodicalCheckActionName = "task_scheduler_hung_routine_cleaner_action_periodical_check";

    public function __construct() {
        add_action( 'task_scheduler_action_after_loading_plugin', array( $this, 'load' ) );
    }

    /**
     * @remark      This method will only be called when the Task Scheduler plugin is activated.
     */
    public function load() {
        add_action( $this->___sPeriodicalCheckActionName, array( $this, 'deleteHungRoutines' ) );
        $this->_scheduleToCheckBeat();
    }

    public function deleteHungRoutines() {
        $_aRoutineIDs = $this->_getProcessing( $this->iElapsedTime );
        $this->_deleteRoutines( $_aRoutineIDs );
    }
        private function _deleteRoutines( array $aRoutineIDs ) {
            foreach( $aRoutineIDs as $_iRoutineID ) {
                $_oRoutine = TaskScheduler_Routine::getInstance( $_iRoutineID );
                $_oRoutine->delete();
            }
        }

        private function _scheduleToCheckBeat() {

            if ( wp_next_scheduled( $this->___sPeriodicalCheckActionName ) ) {
                return;
            }
            wp_schedule_single_event( time() + $this->iCheckInterval, $this->___sPeriodicalCheckActionName );

        }


        /**
         * Returns the array of holding routine(task/thread) IDs that are processing and awaiting.
         *
         * @return        array        An array holding the found routine(post) IDs.
         */
        private function _getProcessing( $iElapsedSeconds,  $iLimit=-1 ) {

            $_aArgs = array(
                'posts_per_page'    => $iLimit,    // -1 for all
                'meta_query'        => array(
                    'relation'      => 'AND',    // or 'OR' can be specified
                    array(    // do not select tasks of empty values of the _next_run_time key.
                        'key'       => '_routine_status',
                        'value'     => array( 'processing'  ),
                        'compare'   => 'IN',
                    ),
                    array(
                        'key'        => '_spawned_time',
                        'value'      => microtime( true ) - $iElapsedSeconds,
                        'type'       => 'numeric',
                        'compare'    => '<=',
                    ),
                ),
           );
            $_oResults = TaskScheduler_RoutineUtility::find( $_aArgs );
            return $_oResults->posts;

        }

}
new TaskSchedulerHungRoutineCleaner;