9 * Schedules a hook to run only once.
11 * Schedules a hook which will be executed once by the WordPress actions core at
12 * a time which you specify. The action will fire off when someone visits your
13 * WordPress site, if the schedule time has passed.
16 * @link https://codex.wordpress.org/Function_Reference/wp_schedule_single_event
18 * @param int $timestamp Timestamp for when to run the event.
19 * @param string $hook Action hook to execute when cron is run.
20 * @param array $args Optional. Arguments to pass to the hook's callback function.
22 function wp_schedule_single_event( $timestamp, $hook, $args = array()) {
23 // don't schedule a duplicate if there's already an identical event due within 10 minutes of it
24 $next = wp_next_scheduled($hook, $args);
25 if ( $next && abs( $next - $timestamp ) <= 10 * MINUTE_IN_SECONDS ) {
29 $crons = _get_cron_array();
30 $event = (object) array( 'hook' => $hook, 'timestamp' => $timestamp, 'schedule' => false, 'args' => $args );
32 * Filter a single event before it is scheduled.
36 * @param object $event An object containing an event's data.
38 $event = apply_filters( 'schedule_event', $event );
40 // A plugin disallowed this event
44 $key = md5(serialize($event->args));
46 $crons[$event->timestamp][$event->hook][$key] = array( 'schedule' => $event->schedule, 'args' => $event->args );
47 uksort( $crons, "strnatcasecmp" );
48 _set_cron_array( $crons );
52 * Schedule a periodic event.
54 * Schedules a hook which will be executed by the WordPress actions core on a
55 * specific interval, specified by you. The action will trigger when someone
56 * visits your WordPress site, if the scheduled time has passed.
58 * Valid values for the recurrence are hourly, daily and twicedaily. These can
59 * be extended using the cron_schedules filter in wp_get_schedules().
61 * Use wp_next_scheduled() to prevent duplicates
65 * @param int $timestamp Timestamp for when to run the event.
66 * @param string $recurrence How often the event should recur.
67 * @param string $hook Action hook to execute when cron is run.
68 * @param array $args Optional. Arguments to pass to the hook's callback function.
69 * @return false|null False on failure, null when complete with scheduling event.
71 function wp_schedule_event( $timestamp, $recurrence, $hook, $args = array()) {
72 $crons = _get_cron_array();
73 $schedules = wp_get_schedules();
75 if ( !isset( $schedules[$recurrence] ) )
78 $event = (object) array( 'hook' => $hook, 'timestamp' => $timestamp, 'schedule' => $recurrence, 'args' => $args, 'interval' => $schedules[$recurrence]['interval'] );
79 /** This filter is documented in wp-includes/cron.php */
80 $event = apply_filters( 'schedule_event', $event );
82 // A plugin disallowed this event
86 $key = md5(serialize($event->args));
88 $crons[$event->timestamp][$event->hook][$key] = array( 'schedule' => $event->schedule, 'args' => $event->args, 'interval' => $event->interval );
89 uksort( $crons, "strnatcasecmp" );
90 _set_cron_array( $crons );
94 * Reschedule a recurring event.
98 * @param int $timestamp Timestamp for when to run the event.
99 * @param string $recurrence How often the event should recur.
100 * @param string $hook Action hook to execute when cron is run.
101 * @param array $args Optional. Arguments to pass to the hook's callback function.
102 * @return false|null False on failure. Null when event is rescheduled.
104 function wp_reschedule_event( $timestamp, $recurrence, $hook, $args = array() ) {
105 $crons = _get_cron_array();
106 $schedules = wp_get_schedules();
107 $key = md5( serialize( $args ) );
110 // First we try to get it from the schedule
111 if ( isset( $schedules[ $recurrence ] ) ) {
112 $interval = $schedules[ $recurrence ]['interval'];
114 // Now we try to get it from the saved interval in case the schedule disappears
115 if ( 0 == $interval ) {
116 $interval = $crons[ $timestamp ][ $hook ][ $key ]['interval'];
118 // Now we assume something is wrong and fail to schedule
119 if ( 0 == $interval ) {
125 if ( $timestamp >= $now ) {
126 $timestamp = $now + $interval;
128 $timestamp = $now + ( $interval - ( ( $now - $timestamp ) % $interval ) );
131 wp_schedule_event( $timestamp, $recurrence, $hook, $args );
135 * Unschedule a previously scheduled cron job.
137 * The $timestamp and $hook parameters are required, so that the event can be
142 * @param int $timestamp Timestamp for when to run the event.
143 * @param string $hook Action hook, the execution of which will be unscheduled.
144 * @param array $args Arguments to pass to the hook's callback function.
145 * Although not passed to a callback function, these arguments are used
146 * to uniquely identify the scheduled event, so they should be the same
147 * as those used when originally scheduling the event.
149 function wp_unschedule_event( $timestamp, $hook, $args = array() ) {
150 $crons = _get_cron_array();
151 $key = md5(serialize($args));
152 unset( $crons[$timestamp][$hook][$key] );
153 if ( empty($crons[$timestamp][$hook]) )
154 unset( $crons[$timestamp][$hook] );
155 if ( empty($crons[$timestamp]) )
156 unset( $crons[$timestamp] );
157 _set_cron_array( $crons );
161 * Unschedule all cron jobs attached to a specific hook.
165 * @param string $hook Action hook, the execution of which will be unscheduled.
166 * @param array $args Optional. Arguments that were to be pass to the hook's callback function.
168 function wp_clear_scheduled_hook( $hook, $args = array() ) {
169 // Backward compatibility
170 // Previously this function took the arguments as discrete vars rather than an array like the rest of the API
171 if ( !is_array($args) ) {
172 _deprecated_argument( __FUNCTION__, '3.0', __('This argument has changed to an array to match the behavior of the other cron functions.') );
173 $args = array_slice( func_get_args(), 1 );
176 // This logic duplicates wp_next_scheduled()
177 // It's required due to a scenario where wp_unschedule_event() fails due to update_option() failing,
178 // and, wp_next_scheduled() returns the same schedule in an infinite loop.
179 $crons = _get_cron_array();
180 if ( empty( $crons ) )
183 $key = md5( serialize( $args ) );
184 foreach ( $crons as $timestamp => $cron ) {
185 if ( isset( $cron[ $hook ][ $key ] ) ) {
186 wp_unschedule_event( $timestamp, $hook, $args );
192 * Retrieve the next timestamp for a cron event.
196 * @param string $hook Action hook to execute when cron is run.
197 * @param array $args Optional. Arguments to pass to the hook's callback function.
198 * @return bool|int The UNIX timestamp of the next time the scheduled event will occur.
200 function wp_next_scheduled( $hook, $args = array() ) {
201 $crons = _get_cron_array();
202 $key = md5(serialize($args));
205 foreach ( $crons as $timestamp => $cron ) {
206 if ( isset( $cron[$hook][$key] ) )
213 * Send request to run cron through HTTP request that doesn't halt page loading.
217 * @return null Cron could not be spawned, because it is not needed to run.
219 function spawn_cron( $gmt_time = 0 ) {
222 $gmt_time = microtime( true );
224 if ( defined('DOING_CRON') || isset($_GET['doing_wp_cron']) )
228 * multiple processes on multiple web servers can run this code concurrently
229 * try to make this as atomic as possible by setting doing_cron switch
231 $lock = get_transient('doing_cron');
233 if ( $lock > $gmt_time + 10 * MINUTE_IN_SECONDS )
236 // don't run if another process is currently running it or more than once every 60 sec.
237 if ( $lock + WP_CRON_LOCK_TIMEOUT > $gmt_time )
241 $crons = _get_cron_array();
242 if ( !is_array($crons) )
245 $keys = array_keys( $crons );
246 if ( isset($keys[0]) && $keys[0] > $gmt_time )
249 if ( defined( 'ALTERNATE_WP_CRON' ) && ALTERNATE_WP_CRON ) {
250 if ( ! empty( $_POST ) || defined( 'DOING_AJAX' ) || defined( 'XMLRPC_REQUEST' ) ) {
254 $doing_wp_cron = sprintf( '%.22F', $gmt_time );
255 set_transient( 'doing_cron', $doing_wp_cron );
258 wp_redirect( add_query_arg( 'doing_wp_cron', $doing_wp_cron, wp_unslash( $_SERVER['REQUEST_URI'] ) ) );
261 // flush any buffers and send the headers
262 while ( @ob_end_flush() );
265 WP_DEBUG ? include_once( ABSPATH . 'wp-cron.php' ) : @include_once( ABSPATH . 'wp-cron.php' );
269 $doing_wp_cron = sprintf( '%.22F', $gmt_time );
270 set_transient( 'doing_cron', $doing_wp_cron );
273 * Filter the cron request arguments.
277 * @param array $cron_request_array {
278 * An array of cron request URL arguments.
280 * @type string $url The cron request URL.
281 * @type int $key The 22 digit GMT microtime.
282 * @type array $args {
283 * An array of cron request arguments.
285 * @type int $timeout The request timeout in seconds. Default .01 seconds.
286 * @type bool $blocking Whether to set blocking for the request. Default false.
287 * @type bool $sslverify Whether SSL should be verified for the request. Default false.
291 $cron_request = apply_filters( 'cron_request', array(
292 'url' => add_query_arg( 'doing_wp_cron', $doing_wp_cron, site_url( 'wp-cron.php' ) ),
293 'key' => $doing_wp_cron,
297 /** This filter is documented in wp-includes/class-http.php */
298 'sslverify' => apply_filters( 'https_local_ssl_verify', false )
302 wp_remote_post( $cron_request['url'], $cron_request['args'] );
306 * Run scheduled callbacks or spawn cron for all scheduled events.
310 * @return null When doesn't need to run Cron.
314 // Prevent infinite loops caused by lack of wp-cron.php
315 if ( strpos($_SERVER['REQUEST_URI'], '/wp-cron.php') !== false || ( defined('DISABLE_WP_CRON') && DISABLE_WP_CRON ) )
318 if ( false === $crons = _get_cron_array() )
321 $gmt_time = microtime( true );
322 $keys = array_keys( $crons );
323 if ( isset($keys[0]) && $keys[0] > $gmt_time )
326 $schedules = wp_get_schedules();
327 foreach ( $crons as $timestamp => $cronhooks ) {
328 if ( $timestamp > $gmt_time ) break;
329 foreach ( (array) $cronhooks as $hook => $args ) {
330 if ( isset($schedules[$hook]['callback']) && !call_user_func( $schedules[$hook]['callback'] ) )
332 spawn_cron( $gmt_time );
339 * Retrieve supported and filtered Cron recurrences.
341 * The supported recurrences are 'hourly' and 'daily'. A plugin may add more by
342 * hooking into the 'cron_schedules' filter. The filter accepts an array of
343 * arrays. The outer array has a key that is the name of the schedule or for
344 * example 'weekly'. The value is an array with two keys, one is 'interval' and
345 * the other is 'display'.
347 * The 'interval' is a number in seconds of when the cron job should run. So for
348 * 'hourly', the time is 3600 or 60*60. For weekly, the value would be
349 * 60*60*24*7 or 604800. The value of 'interval' would then be 604800.
351 * The 'display' is the description. For the 'weekly' key, the 'display' would
352 * be `__( 'Once Weekly' )`.
354 * For your plugin, you will be passed an array. you can easily add your
355 * schedule by doing the following.
357 * // Filter parameter variable name is 'array'.
358 * $array['weekly'] = array(
359 * 'interval' => 604800,
360 * 'display' => __( 'Once Weekly' )
368 function wp_get_schedules() {
370 'hourly' => array( 'interval' => HOUR_IN_SECONDS, 'display' => __( 'Once Hourly' ) ),
371 'twicedaily' => array( 'interval' => 12 * HOUR_IN_SECONDS, 'display' => __( 'Twice Daily' ) ),
372 'daily' => array( 'interval' => DAY_IN_SECONDS, 'display' => __( 'Once Daily' ) ),
375 * Filter the non-default cron schedules.
379 * @param array $new_schedules An array of non-default cron schedules. Default empty.
381 return array_merge( apply_filters( 'cron_schedules', array() ), $schedules );
385 * Retrieve Cron schedule for hook with arguments.
389 * @param string $hook Action hook to execute when cron is run.
390 * @param array $args Optional. Arguments to pass to the hook's callback function.
391 * @return string|bool False, if no schedule. Schedule on success.
393 function wp_get_schedule($hook, $args = array()) {
394 $crons = _get_cron_array();
395 $key = md5(serialize($args));
398 foreach ( $crons as $timestamp => $cron ) {
399 if ( isset( $cron[$hook][$key] ) )
400 return $cron[$hook][$key]['schedule'];
410 * Retrieve cron info array option.
415 * @return array CRON info array.
417 function _get_cron_array() {
418 $cron = get_option('cron');
419 if ( ! is_array($cron) )
422 if ( !isset($cron['version']) )
423 $cron = _upgrade_cron_array($cron);
425 unset($cron['version']);
431 * Updates the CRON option with the new CRON array.
436 * @param array $cron Cron info array from {@link _get_cron_array()}.
438 function _set_cron_array($cron) {
439 $cron['version'] = 2;
440 update_option( 'cron', $cron );
444 * Upgrade a Cron info array.
446 * This function upgrades the Cron info array to version 2.
451 * @param array $cron Cron info array from {@link _get_cron_array()}.
452 * @return array An upgraded Cron info array.
454 function _upgrade_cron_array($cron) {
455 if ( isset($cron['version']) && 2 == $cron['version'])
460 foreach ( (array) $cron as $timestamp => $hooks) {
461 foreach ( (array) $hooks as $hook => $args ) {
462 $key = md5(serialize($args['args']));
463 $new_cron[$timestamp][$hook][$key] = $args;
467 $new_cron['version'] = 2;
468 update_option( 'cron', $new_cron );