* a time which you specify. The action will fire off when someone visits your
* WordPress site, if the schedule time has passed.
*
+ * Note that scheduling an event to occur within 10 minutes of an existing event
+ * with the same action hook will be ignored, unless you pass unique `$args` values
+ * for each scheduled event.
+ *
* @since 2.1.0
- * @link http://codex.wordpress.org/Function_Reference/wp_schedule_single_event
+ * @link https://codex.wordpress.org/Function_Reference/wp_schedule_single_event
*
* @param int $timestamp Timestamp for when to run the event.
* @param string $hook Action hook to execute when cron is run.
* @param array $args Optional. Arguments to pass to the hook's callback function.
+ * @return false|void False when an event is not scheduled.
*/
function wp_schedule_single_event( $timestamp, $hook, $args = array()) {
- // don't schedule a duplicate if there's already an identical event due within 10 minutes of it
+ // Make sure timestamp is a positive integer
+ if ( ! is_numeric( $timestamp ) || $timestamp <= 0 ) {
+ return false;
+ }
+
+ // Don't schedule a duplicate if there's already an identical event due within 10 minutes of it
$next = wp_next_scheduled($hook, $args);
if ( $next && abs( $next - $timestamp ) <= 10 * MINUTE_IN_SECONDS ) {
- return;
+ return false;
}
$crons = _get_cron_array();
$event = (object) array( 'hook' => $hook, 'timestamp' => $timestamp, 'schedule' => false, 'args' => $args );
/**
- * Filter a single event before it is scheduled.
+ * Filters a single event before it is scheduled.
*
* @since 3.1.0
*
* visits your WordPress site, if the scheduled time has passed.
*
* Valid values for the recurrence are hourly, daily and twicedaily. These can
- * be extended using the cron_schedules filter in wp_get_schedules().
+ * be extended using the {@see 'cron_schedules'} filter in wp_get_schedules().
*
* Use wp_next_scheduled() to prevent duplicates
*
* @param string $recurrence How often the event should recur.
* @param string $hook Action hook to execute when cron is run.
* @param array $args Optional. Arguments to pass to the hook's callback function.
- * @return false|null False on failure, null when complete with scheduling event.
+ * @return false|void False when an event is not scheduled.
*/
function wp_schedule_event( $timestamp, $recurrence, $hook, $args = array()) {
+ // Make sure timestamp is a positive integer
+ if ( ! is_numeric( $timestamp ) || $timestamp <= 0 ) {
+ return false;
+ }
+
$crons = _get_cron_array();
$schedules = wp_get_schedules();
* @param string $recurrence How often the event should recur.
* @param string $hook Action hook to execute when cron is run.
* @param array $args Optional. Arguments to pass to the hook's callback function.
- * @return false|null False on failure. Null when event is rescheduled.
+ * @return false|void False when an event is not scheduled.
*/
function wp_reschedule_event( $timestamp, $recurrence, $hook, $args = array() ) {
+ // Make sure timestamp is a positive integer
+ if ( ! is_numeric( $timestamp ) || $timestamp <= 0 ) {
+ return false;
+ }
+
$crons = _get_cron_array();
$schedules = wp_get_schedules();
$key = md5( serialize( $args ) );
* Although not passed to a callback function, these arguments are used
* to uniquely identify the scheduled event, so they should be the same
* as those used when originally scheduling the event.
+ * @return false|void False when an event is not unscheduled.
*/
function wp_unschedule_event( $timestamp, $hook, $args = array() ) {
+ // Make sure timestamp is a positive integer
+ if ( ! is_numeric( $timestamp ) || $timestamp <= 0 ) {
+ return false;
+ }
+
$crons = _get_cron_array();
$key = md5(serialize($args));
unset( $crons[$timestamp][$hook][$key] );
// Backward compatibility
// Previously this function took the arguments as discrete vars rather than an array like the rest of the API
if ( !is_array($args) ) {
- _deprecated_argument( __FUNCTION__, '3.0', __('This argument has changed to an array to match the behavior of the other cron functions.') );
+ _deprecated_argument( __FUNCTION__, '3.0.0', __('This argument has changed to an array to match the behavior of the other cron functions.') );
$args = array_slice( func_get_args(), 1 );
}
*
* @param string $hook Action hook to execute when cron is run.
* @param array $args Optional. Arguments to pass to the hook's callback function.
- * @return bool|int The UNIX timestamp of the next time the scheduled event will occur.
+ * @return false|int The UNIX timestamp of the next time the scheduled event will occur.
*/
function wp_next_scheduled( $hook, $args = array() ) {
$crons = _get_cron_array();
}
/**
- * Send request to run cron through HTTP request that doesn't halt page loading.
+ * Sends a request to run cron through HTTP request that doesn't halt page loading.
*
* @since 2.1.0
*
- * @return null Cron could not be spawned, because it is not needed to run.
+ * @param int $gmt_time Optional. Unix timestamp. Default 0 (current time is used).
*/
function spawn_cron( $gmt_time = 0 ) {
-
if ( ! $gmt_time )
$gmt_time = microtime( true );
return;
/*
- * multiple processes on multiple web servers can run this code concurrently
- * try to make this as atomic as possible by setting doing_cron switch
- */
+ * Get the cron lock, which is a unix timestamp of when the last cron was spawned
+ * and has not finished running.
+ *
+ * Multiple processes on multiple web servers can run this code concurrently,
+ * this lock attempts to make spawning as atomic as possible.
+ */
$lock = get_transient('doing_cron');
if ( $lock > $gmt_time + 10 * MINUTE_IN_SECONDS )
return;
if ( defined( 'ALTERNATE_WP_CRON' ) && ALTERNATE_WP_CRON ) {
- if ( ! empty( $_POST ) || defined( 'DOING_AJAX' ) || defined( 'XMLRPC_REQUEST' ) ) {
+ if ( 'GET' !== $_SERVER['REQUEST_METHOD'] || defined( 'DOING_AJAX' ) || defined( 'XMLRPC_REQUEST' ) ) {
return;
}
return;
}
+ // Set the cron lock with the current unix timestamp, when the cron is being spawned.
$doing_wp_cron = sprintf( '%.22F', $gmt_time );
set_transient( 'doing_cron', $doing_wp_cron );
/**
- * Filter the cron request arguments.
+ * Filters the cron request arguments.
*
* @since 3.5.0
+ * @since 4.5.0 The `$doing_wp_cron` parameter was added.
*
* @param array $cron_request_array {
* An array of cron request URL arguments.
* @type bool $sslverify Whether SSL should be verified for the request. Default false.
* }
* }
+ * @param string $doing_wp_cron The unix timestamp of the cron lock.
*/
$cron_request = apply_filters( 'cron_request', array(
'url' => add_query_arg( 'doing_wp_cron', $doing_wp_cron, site_url( 'wp-cron.php' ) ),
'args' => array(
'timeout' => 0.01,
'blocking' => false,
- /** This filter is documented in wp-includes/class-http.php */
+ /** This filter is documented in wp-includes/class-wp-http-streams.php */
'sslverify' => apply_filters( 'https_local_ssl_verify', false )
)
- ) );
+ ), $doing_wp_cron );
wp_remote_post( $cron_request['url'], $cron_request['args'] );
}
* Run scheduled callbacks or spawn cron for all scheduled events.
*
* @since 2.1.0
- *
- * @return null When doesn't need to run Cron.
*/
function wp_cron() {
-
// Prevent infinite loops caused by lack of wp-cron.php
if ( strpos($_SERVER['REQUEST_URI'], '/wp-cron.php') !== false || ( defined('DISABLE_WP_CRON') && DISABLE_WP_CRON ) )
return;
* Retrieve supported and filtered Cron recurrences.
*
* The supported recurrences are 'hourly' and 'daily'. A plugin may add more by
- * hooking into the 'cron_schedules' filter. The filter accepts an array of
+ * hooking into the {@see 'cron_schedules'} filter. The filter accepts an array of
* arrays. The outer array has a key that is the name of the schedule or for
* example 'weekly'. The value is an array with two keys, one is 'interval' and
* the other is 'display'.
'daily' => array( 'interval' => DAY_IN_SECONDS, 'display' => __( 'Once Daily' ) ),
);
/**
- * Filter the non-default cron schedules.
+ * Filters the non-default cron schedules.
*
* @since 2.1.0
*
*
* @param string $hook Action hook to execute when cron is run.
* @param array $args Optional. Arguments to pass to the hook's callback function.
- * @return string|bool False, if no schedule. Schedule on success.
+ * @return string|false False, if no schedule. Schedule on success.
*/
function wp_get_schedule($hook, $args = array()) {
$crons = _get_cron_array();
* @since 2.1.0
* @access private
*
- * @return array CRON info array.
+ * @return false|array CRON info array.
*/
function _get_cron_array() {
$cron = get_option('cron');
* @since 2.1.0
* @access private
*
- * @param array $cron Cron info array from {@link _get_cron_array()}.
+ * @param array $cron Cron info array from _get_cron_array().
*/
function _set_cron_array($cron) {
$cron['version'] = 2;
* @since 2.1.0
* @access private
*
- * @param array $cron Cron info array from {@link _get_cron_array()}.
+ * @param array $cron Cron info array from _get_cron_array().
* @return array An upgraded Cron info array.
*/
function _upgrade_cron_array($cron) {