From 5ebcc1d3ea674397d903d9119b97ce89380fa545 Mon Sep 17 00:00:00 2001 From: ryan Date: Fri, 9 Sep 2011 19:59:44 +0000 Subject: [PATCH] Improve cron locking. Avoid multiple cron processes looping over the same events. fixes #17462 git-svn-id: http://svn.automattic.com/wordpress/trunk@18659 1a063a9b-81f0-0310-95a4-ce76da25c4cd --- wp-cron.php | 56 +++++++++++++++++++++++++++---- wp-includes/cache.php | 8 +++-- wp-includes/cron.php | 18 +++++----- wp-includes/default-constants.php | 6 ++++ 4 files changed, 71 insertions(+), 17 deletions(-) diff --git a/wp-cron.php b/wp-cron.php index 19427c5c42..a84c4635df 100644 --- a/wp-cron.php +++ b/wp-cron.php @@ -26,6 +26,24 @@ if ( !defined('ABSPATH') ) { require_once('./wp-load.php'); } +// Uncached doing_cron transient fetch +function _get_cron_lock() { + global $_wp_using_ext_object_cache, $wpdb; + + $value = 0; + if ( $_wp_using_ext_object_cache ) { + // Skip local cache and force refetch of doing_cron transient in case + // another processs updated the cache + $value = wp_cache_get( 'doing_cron', 'transient', true ); + } else { + $row = $wpdb->get_row( $wpdb->prepare( "SELECT option_value FROM $wpdb->options WHERE option_name = %s LIMIT 1", '_transient_doing_cron' ) ); + if ( is_object( $row ) ) + $value = $row->option_value; + } + + return $value; +} + if ( false === $crons = _get_cron_array() ) die(); @@ -35,26 +53,52 @@ $local_time = time(); if ( isset($keys[0]) && $keys[0] > $local_time ) die(); -foreach ($crons as $timestamp => $cronhooks) { +$doing_cron_transient = get_transient( 'doing_cron'); + +// Use global $doing_wp_cron lock otherwise use the GET lock. If no lock, trying grabbing a new lock. +if ( empty( $doing_wp_cron ) ) { + if ( empty( $_GET[ 'doing_wp_cron' ] ) ) { + // Called from external script/job. Try setting a lock. + if ( $doing_cron_transient && ( $doing_cron_transient + WP_CRON_LOCK_TIMEOUT > $local_time ) ) + return; + $doing_cron_transient = $doing_wp_cron = time(); + set_transient( 'doing_cron', $doing_wp_cron ); + } else { + $doing_wp_cron = $_GET[ 'doing_wp_cron' ]; + } +} + +// Check lock +if ( $doing_cron_transient != $doing_wp_cron ) + return; + +foreach ( $crons as $timestamp => $cronhooks ) { if ( $timestamp > $local_time ) break; - foreach ($cronhooks as $hook => $keys) { + foreach ( $cronhooks as $hook => $keys ) { - foreach ($keys as $k => $v) { + foreach ( $keys as $k => $v ) { $schedule = $v['schedule']; - if ($schedule != false) { + if ( $schedule != false ) { $new_args = array($timestamp, $schedule, $hook, $v['args']); call_user_func_array('wp_reschedule_event', $new_args); } - wp_unschedule_event($timestamp, $hook, $v['args']); + wp_unschedule_event( $timestamp, $hook, $v['args'] ); - do_action_ref_array($hook, $v['args']); + do_action_ref_array( $hook, $v['args'] ); + + // If the hook ran too long and another cron process stole the lock, quit. + if ( _get_cron_lock() != $doing_wp_cron ) + return; } } } +if ( _get_cron_lock() == $doing_wp_cron ) + delete_transient( 'doing_cron' ); + die(); diff --git a/wp-includes/cache.php b/wp-includes/cache.php index 5fbc06916d..70753aa2d4 100644 --- a/wp-includes/cache.php +++ b/wp-includes/cache.php @@ -102,13 +102,14 @@ function wp_cache_flush() { * * @param int|string $key What the contents in the cache are called * @param string $group Where the cache contents are grouped + * @param bool $force Whether to force an update of the local cache from the persistent cache (default is false) * @return bool|mixed False on failure to retrieve contents or the cache * contents on success */ -function wp_cache_get($key, $group = '') { +function wp_cache_get( $key, $group = '', $force = false ) { global $wp_object_cache; - return $wp_object_cache->get($key, $group); + return $wp_object_cache->get( $key, $group, $force ); } /** @@ -403,10 +404,11 @@ class WP_Object_Cache { * * @param int|string $key What the contents in the cache are called * @param string $group Where the cache contents are grouped + * @param string $force Whether to force a refetch rather than relying on the local cache (default is false) * @return bool|mixed False on failure to retrieve contents or the cache * contents on success */ - function get($key, $group = 'default') { + function get( $key, $group = 'default', $force = false) { if ( empty ($group) ) $group = 'default'; diff --git a/wp-includes/cron.php b/wp-includes/cron.php index b7d04f2a2f..27f29711a5 100644 --- a/wp-includes/cron.php +++ b/wp-includes/cron.php @@ -204,13 +204,13 @@ function spawn_cron( $local_time = 0 ) { * multiple processes on multiple web servers can run this code concurrently * try to make this as atomic as possible by setting doing_cron switch */ - $flag = get_transient('doing_cron'); + $lock = get_transient('doing_cron'); - if ( $flag > $local_time + 10*60 ) - $flag = 0; + if ( $lock > $local_time + 10*60 ) + $lock = 0; // don't run if another process is currently running it or more than once every 60 sec. - if ( $flag + 60 > $local_time ) + if ( $lock + WP_CRON_LOCK_TIMEOUT > $local_time ) return; //sanity check @@ -226,10 +226,11 @@ function spawn_cron( $local_time = 0 ) { if ( !empty($_POST) || defined('DOING_AJAX') ) return; - set_transient( 'doing_cron', $local_time ); + $doing_wp_cron = $local_time; + set_transient( 'doing_cron', $doing_wp_cron ); ob_start(); - wp_redirect( add_query_arg('doing_wp_cron', '', stripslashes($_SERVER['REQUEST_URI'])) ); + wp_redirect( add_query_arg('doing_wp_cron', $doing_wp_cron, stripslashes($_SERVER['REQUEST_URI'])) ); echo ' '; // flush any buffers and send the headers @@ -240,9 +241,10 @@ function spawn_cron( $local_time = 0 ) { return; } - set_transient( 'doing_cron', $local_time ); + $doing_wp_cron = $local_time; + set_transient( 'doing_cron', $doing_wp_cron ); - $cron_url = get_option( 'siteurl' ) . '/wp-cron.php?doing_wp_cron'; + $cron_url = get_option( 'siteurl' ) . '/wp-cron.php?doing_wp_cron=' . $doing_wp_cron; wp_remote_post( $cron_url, array('timeout' => 0.01, 'blocking' => false, 'sslverify' => apply_filters('https_local_ssl_verify', true)) ); } diff --git a/wp-includes/default-constants.php b/wp-includes/default-constants.php index b11c6ab040..9c6535e21a 100644 --- a/wp-includes/default-constants.php +++ b/wp-includes/default-constants.php @@ -268,6 +268,12 @@ function wp_functionality_constants( ) { if ( !defined('WP_POST_REVISIONS') ) define('WP_POST_REVISIONS', true); + + /** + * @since 3.3.0 + */ + if ( !defined( 'WP_CRON_LOCK_TIMEOUT' ) ) + define('WP_CRON_LOCK_TIMEOUT', 60); // In seconds } /**