1<?php
  2/**
  3 * A pseudo-cron daemon for scheduling WordPress tasks.
  4 *
  5 * WP-Cron is triggered when the site receives a visit. In the scenario
  6 * where a site may not receive enough visits to execute scheduled tasks
  7 * in a timely manner, this file can be called directly or via a server
  8 * cron daemon for X number of times.
  9 *
 10 * Defining DISABLE_WP_CRON as true and calling this file directly are
 11 * mutually exclusive and the latter does not rely on the former to work.
 12 *
 13 * The HTTP request to this file will not slow down the visitor who happens to
 14 * visit when a scheduled cron event runs.
 15 *
 16 * @package WordPress
 17 */
 18
 19ignore_user_abort( true );
 20
 21if ( ! headers_sent() ) {
 22	header( 'Expires: Wed, 11 Jan 1984 05:00:00 GMT' );
 23	header( 'Cache-Control: no-cache, must-revalidate, max-age=0' );
 24}
 25
 26// Don't run cron until the request finishes, if possible.
 27if ( function_exists( 'fastcgi_finish_request' ) ) {
 28	fastcgi_finish_request();
 29} elseif ( function_exists( 'litespeed_finish_request' ) ) {
 30	litespeed_finish_request();
 31}
 32
 33if ( ! empty( $_POST ) || defined( 'DOING_AJAX' ) || defined( 'DOING_CRON' ) ) {
 34	die();
 35}
 36
 37/**
 38 * Tell WordPress the cron task is running.
 39 *
 40 * @var bool
 41 */
 42define( 'DOING_CRON', true );
 43
 44if ( ! defined( 'ABSPATH' ) ) {
 45	/** Set up WordPress environment */
 46	require_once __DIR__ . '/wp-load.php';
 47}
 48
 49// Attempt to raise the PHP memory limit for cron event processing.
 50wp_raise_memory_limit( 'cron' );
 51
 52/**
 53 * Retrieves the cron lock.
 54 *
 55 * Returns the uncached `doing_cron` transient.
 56 *
 57 * @ignore
 58 * @since 3.3.0
 59 *
 60 * @global wpdb $wpdb WordPress database abstraction object.
 61 *
 62 * @return string|int|false Value of the `doing_cron` transient, 0|false otherwise.
 63 */
 64function _get_cron_lock() {
 65	global $wpdb;
 66
 67	$value = 0;
 68	if ( wp_using_ext_object_cache() ) {
 69		/*
 70		 * Skip local cache and force re-fetch of doing_cron transient
 71		 * in case another process updated the cache.
 72		 */
 73		$value = wp_cache_get( 'doing_cron', 'transient', true );
 74	} else {
 75		$row = $wpdb->get_row( $wpdb->prepare( "SELECT option_value FROM $wpdb->options WHERE option_name = %s LIMIT 1", '_transient_doing_cron' ) );
 76		if ( is_object( $row ) ) {
 77			$value = $row->option_value;
 78		}
 79	}
 80
 81	return $value;
 82}
 83
 84$crons = wp_get_ready_cron_jobs();
 85if ( empty( $crons ) ) {
 86	die();
 87}
 88
 89$gmt_time = microtime( true );
 90
 91// The cron lock: a unix timestamp from when the cron was spawned.
 92$doing_cron_transient = get_transient( 'doing_cron' );
 93
 94// Use global $doing_wp_cron lock, otherwise use the GET lock. If no lock, try to grab a new lock.
 95if ( empty( $doing_wp_cron ) ) {
 96	if ( empty( $_GET['doing_wp_cron'] ) ) {
 97		// Called from external script/job. Try setting a lock.
 98		if ( $doing_cron_transient && ( $doing_cron_transient + WP_CRON_LOCK_TIMEOUT > $gmt_time ) ) {
 99			return;
100		}
101		$doing_wp_cron        = sprintf( '%.22F', microtime( true ) );
102		$doing_cron_transient = $doing_wp_cron;
103		set_transient( 'doing_cron', $doing_wp_cron );
104	} else {
105		$doing_wp_cron = $_GET['doing_wp_cron'];
106	}
107}
108
109/*
110 * The cron lock (a unix timestamp set when the cron was spawned),
111 * must match $doing_wp_cron (the "key").
112 */
113if ( $doing_cron_transient !== $doing_wp_cron ) {
114	return;
115}
116
117foreach ( $crons as $timestamp => $cronhooks ) {
118	if ( $timestamp > $gmt_time ) {
119		break;
120	}
121
122	foreach ( $cronhooks as $hook => $keys ) {
123
124		foreach ( $keys as $k => $v ) {
125
126			$schedule = $v['schedule'];
127
128			if ( $schedule ) {
129				$result = wp_reschedule_event( $timestamp, $schedule, $hook, $v['args'], true );
130
131				if ( is_wp_error( $result ) ) {
132					error_log(
133						sprintf(
134							/* translators: 1: Hook name, 2: Error code, 3: Error message, 4: Event data. */
135							__( 'Cron reschedule event error for hook: %1$s, Error code: %2$s, Error message: %3$s, Data: %4$s' ),
136							$hook,
137							$result->get_error_code(),
138							$result->get_error_message(),
139							wp_json_encode( $v )
140						)
141					);
142
143					/**
144					 * Fires if an error happens when rescheduling a cron event.
145					 *
146					 * @since 6.1.0
147					 *
148					 * @param WP_Error $result The WP_Error object.
149					 * @param string   $hook   Action hook to execute when the event is run.
150					 * @param array    $v      Event data.
151					 */
152					do_action( 'cron_reschedule_event_error', $result, $hook, $v );
153				}
154			}
155
156			$result = wp_unschedule_event( $timestamp, $hook, $v['args'], true );
157
158			if ( is_wp_error( $result ) ) {
159				error_log(
160					sprintf(
161						/* translators: 1: Hook name, 2: Error code, 3: Error message, 4: Event data. */
162						__( 'Cron unschedule event error for hook: %1$s, Error code: %2$s, Error message: %3$s, Data: %4$s' ),
163						$hook,
164						$result->get_error_code(),
165						$result->get_error_message(),
166						wp_json_encode( $v )
167					)
168				);
169
170				/**
171				 * Fires if an error happens when unscheduling a cron event.
172				 *
173				 * @since 6.1.0
174				 *
175				 * @param WP_Error $result The WP_Error object.
176				 * @param string   $hook   Action hook to execute when the event is run.
177				 * @param array    $v      Event data.
178				 */
179				do_action( 'cron_unschedule_event_error', $result, $hook, $v );
180			}
181
182			/**
183			 * Fires scheduled events.
184			 *
185			 * @ignore
186			 * @since 2.1.0
187			 *
188			 * @param string $hook Name of the hook that was scheduled to be fired.
189			 * @param array  $args The arguments to be passed to the hook.
190			 */
191			do_action_ref_array( $hook, $v['args'] );
192
193			// If the hook ran too long and another cron process stole the lock, quit.
194			if ( _get_cron_lock() !== $doing_wp_cron ) {
195				return;
196			}
197		}
198	}
199}
200
201if ( _get_cron_lock() === $doing_wp_cron ) {
202	delete_transient( 'doing_cron' );
203}
204
205die();
206