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 http://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 in the next 10 minutes
24 $next = wp_next_scheduled($hook, $args);
25 if ( $next && $next <= $timestamp + 10 * MINUTE_IN_SECONDS )
28 $crons = _get_cron_array();
29 $event = (object) array( 'hook' => $hook, 'timestamp' => $timestamp, 'schedule' => false, 'args' => $args );
31 * Filter a single event before it is scheduled.
35 * @param object $event An object containing an event's data.
37 $event = apply_filters( 'schedule_event', $event );
39 // A plugin disallowed this event
43 $key = md5(serialize($event->args));
45 $crons[$event->timestamp][$event->hook][$key] = array( 'schedule' => $event->schedule, 'args' => $event->args );
46 uksort( $crons, "strnatcasecmp" );
47 _set_cron_array( $crons );
51 * Schedule a periodic event.
53 * Schedules a hook which will be executed by the WordPress actions core on a
54 * specific interval, specified by you. The action will trigger when someone
55 * visits your WordPress site, if the scheduled time has passed.
57 * Valid values for the recurrence are hourly, daily and twicedaily. These can
58 * be extended using the cron_schedules filter in wp_get_schedules().
60 * Use wp_next_scheduled() to prevent duplicates
64 * @param int $timestamp Timestamp for when to run the event.
65 * @param string $recurrence How often the event should recur.
66 * @param string $hook Action hook to execute when cron is run.
67 * @param array $args Optional. Arguments to pass to the hook's callback function.
68 * @return bool|null False on failure, null when complete with scheduling event.
70 function wp_schedule_event( $timestamp, $recurrence, $hook, $args = array()) {
71 $crons = _get_cron_array();
72 $schedules = wp_get_schedules();
74 if ( !isset( $schedules[$recurrence] ) )
77 $event = (object) array( 'hook' => $hook, 'timestamp' => $timestamp, 'schedule' => $recurrence, 'args' => $args, 'interval' => $schedules[$recurrence]['interval'] );
78 /** This filter is documented in wp-includes/cron.php */
79 $event = apply_filters( 'schedule_event', $event );
81 // A plugin disallowed this event
85 $key = md5(serialize($event->args));
87 $crons[$event->timestamp][$event->hook][$key] = array( 'schedule' => $event->schedule, 'args' => $event->args, 'interval' => $event->interval );
88 uksort( $crons, "strnatcasecmp" );
89 _set_cron_array( $crons );
93 * Reschedule a recurring event.
97 * @param int $timestamp Timestamp for when to run the event.
98 * @param string $recurrence How often the event should recur.
99 * @param string $hook Action hook to execute when cron is run.
100 * @param array $args Optional. Arguments to pass to the hook's callback function.
101 * @return bool|null False on failure. Null when event is rescheduled.
103 function wp_reschedule_event( $timestamp, $recurrence, $hook, $args = array() ) {
104 $crons = _get_cron_array();
105 $schedules = wp_get_schedules();
106 $key = md5( serialize( $args ) );
109 // First we try to get it from the schedule
110 if ( isset( $schedules[ $recurrence ] ) ) {
111 $interval = $schedules[ $recurrence ]['interval'];
113 // Now we try to get it from the saved interval in case the schedule disappears
114 if ( 0 == $interval ) {
115 $interval = $crons[ $timestamp ][ $hook ][ $key ]['interval'];
117 // Now we assume something is wrong and fail to schedule
118 if ( 0 == $interval ) {
124 if ( $timestamp >= $now ) {
125 $timestamp = $now + $interval;
127 $timestamp = $now + ( $interval - ( ( $now - $timestamp ) % $interval ) );
130 wp_schedule_event( $timestamp, $recurrence, $hook, $args );
134 * Unschedule a previously scheduled cron job.
136 * The $timestamp and $hook parameters are required, so that the event can be
141 * @param int $timestamp Timestamp for when to run the event.
142 * @param string $hook Action hook, the execution of which will be unscheduled.
143 * @param array $args Arguments to pass to the hook's callback function.
144 * Although not passed to a callback function, these arguments are used
145 * to uniquely identify the scheduled event, so they should be the same
146 * as those used when originally scheduling the event.
148 function wp_unschedule_event( $timestamp, $hook, $args = array() ) {
149 $crons = _get_cron_array();
150 $key = md5(serialize($args));
151 unset( $crons[$timestamp][$hook][$key] );
152 if ( empty($crons[$timestamp][$hook]) )
153 unset( $crons[$timestamp][$hook] );
154 if ( empty($crons[$timestamp]) )
155 unset( $crons[$timestamp] );
156 _set_cron_array( $crons );
160 * Unschedule all cron jobs attached to a specific hook.
164 * @param string $hook Action hook, the execution of which will be unscheduled.
165 * @param array $args Optional. Arguments that were to be pass to the hook's callback function.
167 function wp_clear_scheduled_hook( $hook, $args = array() ) {
168 // Backward compatibility
169 // Previously this function took the arguments as discrete vars rather than an array like the rest of the API
170 if ( !is_array($args) ) {
171 _deprecated_argument( __FUNCTION__, '3.0', __('This argument has changed to an array to match the behavior of the other cron functions.') );
172 $args = array_slice( func_get_args(), 1 );
175 // This logic duplicates wp_next_scheduled()
176 // It's required due to a scenario where wp_unschedule_event() fails due to update_option() failing,
177 // and, wp_next_scheduled() returns the same schedule in an infinite loop.
178 $crons = _get_cron_array();
179 if ( empty( $crons ) )
182 $key = md5( serialize( $args ) );
183 foreach ( $crons as $timestamp => $cron ) {
184 if ( isset( $cron[ $hook ][ $key ] ) ) {
185 wp_unschedule_event( $timestamp, $hook, $args );
191 * Retrieve the next timestamp for a cron event.
195 * @param string $hook Action hook to execute when cron is run.
196 * @param array $args Optional. Arguments to pass to the hook's callback function.
197 * @return bool|int The UNIX timestamp of the next time the scheduled event will occur.
199 function wp_next_scheduled( $hook, $args = array() ) {
200 $crons = _get_cron_array();
201 $key = md5(serialize($args));
204 foreach ( $crons as $timestamp => $cron ) {
205 if ( isset( $cron[$hook][$key] ) )
212 * Send request to run cron through HTTP request that doesn't halt page loading.
216 * @return null Cron could not be spawned, because it is not needed to run.
218 function spawn_cron( $gmt_time = 0 ) {
221 $gmt_time = microtime( true );
223 if ( defined('DOING_CRON') || isset($_GET['doing_wp_cron']) )
227 * multiple processes on multiple web servers can run this code concurrently
228 * try to make this as atomic as possible by setting doing_cron switch
230 $lock = get_transient('doing_cron');
232 if ( $lock > $gmt_time + 10 * MINUTE_IN_SECONDS )
235 // don't run if another process is currently running it or more than once every 60 sec.
236 if ( $lock + WP_CRON_LOCK_TIMEOUT > $gmt_time )
240 $crons = _get_cron_array();
241 if ( !is_array($crons) )
244 $keys = array_keys( $crons );
245 if ( isset($keys[0]) && $keys[0] > $gmt_time )
248 if ( defined('ALTERNATE_WP_CRON') && ALTERNATE_WP_CRON ) {
249 if ( !empty($_POST) || defined('DOING_AJAX') )
252 $doing_wp_cron = sprintf( '%.22F', $gmt_time );
253 set_transient( 'doing_cron', $doing_wp_cron );
256 wp_redirect( add_query_arg( 'doing_wp_cron', $doing_wp_cron, wp_unslash( $_SERVER['REQUEST_URI'] ) ) );
259 // flush any buffers and send the headers
260 while ( @ob_end_flush() );
263 WP_DEBUG ? include_once( ABSPATH . 'wp-cron.php' ) : @include_once( ABSPATH . 'wp-cron.php' );
267 $doing_wp_cron = sprintf( '%.22F', $gmt_time );
268 set_transient( 'doing_cron', $doing_wp_cron );
271 * Filter the cron request arguments.
275 * @param array $cron_request_array {
276 * An array of cron request URL arguments.
278 * @type string $url The cron request URL.
279 * @type int $key The 22 digit GMT microtime.
280 * @type array $args {
281 * An array of cron request arguments.
283 * @type int $timeout The request timeout in seconds. Default .01 seconds.
284 * @type bool $blocking Whether to set blocking for the request. Default false.
285 * @type bool $sslverify Whether SSL should be verified for the request. Default false.
289 $cron_request = apply_filters( 'cron_request', array(
290 'url' => add_query_arg( 'doing_wp_cron', $doing_wp_cron, site_url( 'wp-cron.php' ) ),
291 'key' => $doing_wp_cron,
295 /** This filter is documented in wp-includes/class-http.php */
296 'sslverify' => apply_filters( 'https_local_ssl_verify', false )
300 wp_remote_post( $cron_request['url'], $cron_request['args'] );
304 * Run scheduled callbacks or spawn cron for all scheduled events.
308 * @return null When doesn't need to run Cron.
312 // Prevent infinite loops caused by lack of wp-cron.php
313 if ( strpos($_SERVER['REQUEST_URI'], '/wp-cron.php') !== false || ( defined('DISABLE_WP_CRON') && DISABLE_WP_CRON ) )
316 if ( false === $crons = _get_cron_array() )
319 $gmt_time = microtime( true );
320 $keys = array_keys( $crons );
321 if ( isset($keys[0]) && $keys[0] > $gmt_time )
324 $schedules = wp_get_schedules();
325 foreach ( $crons as $timestamp => $cronhooks ) {
326 if ( $timestamp > $gmt_time ) break;
327 foreach ( (array) $cronhooks as $hook => $args ) {
328 if ( isset($schedules[$hook]['callback']) && !call_user_func( $schedules[$hook]['callback'] ) )
330 spawn_cron( $gmt_time );
337 * Retrieve supported and filtered Cron recurrences.
339 * The supported recurrences are 'hourly' and 'daily'. A plugin may add more by
340 * hooking into the 'cron_schedules' filter. The filter accepts an array of
341 * arrays. The outer array has a key that is the name of the schedule or for
342 * example 'weekly'. The value is an array with two keys, one is 'interval' and
343 * the other is 'display'.
345 * The 'interval' is a number in seconds of when the cron job should run. So for
346 * 'hourly', the time is 3600 or 60*60. For weekly, the value would be
347 * 60*60*24*7 or 604800. The value of 'interval' would then be 604800.
349 * The 'display' is the description. For the 'weekly' key, the 'display' would
350 * be <code>__('Once Weekly')</code>.
352 * For your plugin, you will be passed an array. you can easily add your
353 * schedule by doing the following.
355 * // filter parameter variable name is 'array'
356 * $array['weekly'] = array(
357 * 'interval' => 604800,
358 * 'display' => __('Once Weekly')
366 function wp_get_schedules() {
368 'hourly' => array( 'interval' => HOUR_IN_SECONDS, 'display' => __( 'Once Hourly' ) ),
369 'twicedaily' => array( 'interval' => 12 * HOUR_IN_SECONDS, 'display' => __( 'Twice Daily' ) ),
370 'daily' => array( 'interval' => DAY_IN_SECONDS, 'display' => __( 'Once Daily' ) ),
373 * Filter the non-default cron schedules.
377 * @param array $new_schedules An array of non-default cron schedules. Default empty.
379 return array_merge( apply_filters( 'cron_schedules', array() ), $schedules );
383 * Retrieve Cron schedule for hook with arguments.
387 * @param string $hook Action hook to execute when cron is run.
388 * @param array $args Optional. Arguments to pass to the hook's callback function.
389 * @return string|bool False, if no schedule. Schedule on success.
391 function wp_get_schedule($hook, $args = array()) {
392 $crons = _get_cron_array();
393 $key = md5(serialize($args));
396 foreach ( $crons as $timestamp => $cron ) {
397 if ( isset( $cron[$hook][$key] ) )
398 return $cron[$hook][$key]['schedule'];
408 * Retrieve cron info array option.
413 * @return array CRON info array.
415 function _get_cron_array() {
416 $cron = get_option('cron');
417 if ( ! is_array($cron) )
420 if ( !isset($cron['version']) )
421 $cron = _upgrade_cron_array($cron);
423 unset($cron['version']);
429 * Updates the CRON option with the new CRON array.
434 * @param array $cron Cron info array from {@link _get_cron_array()}.
436 function _set_cron_array($cron) {
437 $cron['version'] = 2;
438 update_option( 'cron', $cron );
442 * Upgrade a Cron info array.
444 * This function upgrades the Cron info array to version 2.
449 * @param array $cron Cron info array from {@link _get_cron_array()}.
450 * @return array An upgraded Cron info array.
452 function _upgrade_cron_array($cron) {
453 if ( isset($cron['version']) && 2 == $cron['version'])
458 foreach ( (array) $cron as $timestamp => $hooks) {
459 foreach ( (array) $hooks as $hook => $args ) {
460 $key = md5(serialize($args['args']));
461 $new_cron[$timestamp][$hook][$key] = $args;
465 $new_cron['version'] = 2;
466 update_option( 'cron', $new_cron );