Cron spawning improvement, see #9005

git-svn-id: http://svn.automattic.com/wordpress/trunk@10521 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-cron.php

@@ -11,27 +11,31 @@
 
 ignore_user_abort(true);
 
+if ( !empty($_POST) || defined('DOING_AJAX') || defined('DOING_CRON') )
+	die();
+
 /**
  * Tell WordPress we are doing the CRON task.
  *
  * @var bool
  */
 define('DOING_CRON', true);
-/** Setup WordPress environment */
-require_once('./wp-load.php');
 
-$local_time = time();
-
-$crons = _get_cron_array();
-$keys = array_keys( $crons );
-
-if (!is_array($crons) || $keys[0] > $local_time) {
-	set_transient('doing_cron', 0);
-	return;
+if ( !defined('ABSPATH') ) {
+	/** Setup WordPress environment */
+	require_once('./wp-load.php');
 }
 
-foreach ($crons as $timestamp  => $cronhooks) {
+if ( false === $crons = _get_cron_array() )
+	die();
 
+$keys = array_keys( $crons );
+$local_time = time();
+
+if ( isset($keys[0]) && $keys[0] > $local_time )
+	die();
+
+foreach ($crons as $timestamp  => $cronhooks) {
 	if ( $timestamp > $local_time )
 		break;
 
@@ -53,8 +57,4 @@ foreach ($crons as $timestamp  => $cronhooks) {
 	}
 }
 
-set_transient('doing_cron', 0);
-
 die();
-
-?>

wp-includes/cron.php

@@ -160,7 +160,13 @@ function wp_next_scheduled( $hook, $args = array() ) {
  *
  * @return null Cron could not be spawned, because it is not needed to run.
  */
-function spawn_cron( $local_time ) {
+function spawn_cron( $local_time = 0 ) {
+
+	if ( !$local_time )
+		$local_time = time();
+
+	if ( defined('DOING_CRON') || isset($_GET['doing_wp_cron']) )
+		return;
 
 	/*
 	 * do not even start the cron if local server timer has drifted
@@ -170,37 +176,50 @@ function spawn_cron( $local_time ) {
 	if ( !$timer_accurate )
 		return;
 
-	//sanity check
-	$crons = _get_cron_array();
-	if ( !is_array($crons) )
-		return;
-
-	$keys = array_keys( $crons );
-	$timestamp =  $keys[0];
-	if ( $timestamp > $local_time )
-		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
 	*/
 	$flag = get_transient('doing_cron');
 
-	// clean up potential invalid value resulted from various system chaos
-	if ( $flag != 0 ) {
-		if ( $flag > $local_time + 10*60 || $flag < $local_time - 10*60 ) {
-			set_transient('doing_cron', 0);
-			$flag = 0;
-		}
-	}
+	if ( $flag > $local_time + 10*60 )
+		$flag = 0;
 
-	//don't run if another process is currently running it
-	if ( $flag > $local_time )
+	// don't run if another process is currently running it or more than once every 60 sec.
+	if ( $flag + 60 > $local_time )
 		return;
 
-	set_transient( 'doing_cron', $local_time + 30 );
+	//sanity check
+	$crons = _get_cron_array();
+	if ( !is_array($crons) )
+		return;
 
-	add_action('wp_head', 'spawn_cron_request');
+	$keys = array_keys( $crons );
+	if ( isset($keys[0]) && $keys[0] > $local_time )
+		return;
+
+	if ( defined('ALTERNATE_WP_CRON') && ALTERNATE_WP_CRON ) {
+		if ( !empty($_POST) || defined('DOING_AJAX') )
+			return;
+
+		set_transient( 'doing_cron', $local_time );
+
+		ob_start();
+		wp_redirect( add_query_arg('doing_wp_cron', '', stripslashes($_SERVER['REQUEST_URI'])) );
+		echo ' ';
+
+		// flush any buffers and send the headers
+		while ( @ob_end_flush() );
+		flush();
+
+		@include_once(ABSPATH . 'wp-cron.php');
+		return;
+	}
+
+	set_transient( 'doing_cron', $local_time );
+
+	$cron_url = get_option( 'siteurl' ) . '/wp-cron.php?doing_wp_cron';
+	wp_remote_post( $cron_url, array('timeout' => 0.01, 'blocking' => false) );
 }
 
 /**
@@ -213,19 +232,17 @@ function spawn_cron( $local_time ) {
 function wp_cron() {
 
 	// Prevent infinite loops caused by lack of wp-cron.php
-	if ( strpos($_SERVER['REQUEST_URI'], '/wp-cron.php') !== false )
+	if ( strpos($_SERVER['REQUEST_URI'], '/wp-cron.php') !== false || ( defined('DISABLE_WP_CRON') && DISABLE_WP_CRON ) )
 		return;
 
-	$crons = _get_cron_array();
-
-	if ( !is_array($crons) )
-		return;
-
-	$keys = array_keys( $crons );
-	if ( isset($keys[0]) && $keys[0] > time() )
+	if ( false === $crons = _get_cron_array() )
 		return;
 
 	$local_time = time();
+	$keys = array_keys( $crons );
+	if ( isset($keys[0]) && $keys[0] > $local_time )
+		return;
+
 	$schedules = wp_get_schedules();
 	foreach ( $crons as $timestamp => $cronhooks ) {
 		if ( $timestamp > $local_time ) break;
@@ -370,14 +387,4 @@ function check_server_timer( $local_time ) {
 	return true;
 }
 
-function spawn_cron_request() {
-?>
-<script type="text/javascript">
-/* <![CDATA[ */
-window.setTimeout(function(){var x;if(window.XMLHttpRequest){x=new XMLHttpRequest();}else{try{x=new ActiveXObject('Msxml2.XMLHTTP');}catch(e){try{x=new ActiveXObject('Microsoft.XMLHTTP');}catch(e){};}}if(x){x.open('GET','<?php echo get_option('siteurl'); ?>/wp-cron.php?'+(new Date()).getTime(), true);x.send('');}},10);
-/* ]]> */
-</script>
-<?php
-}
-
 ?>

wp-includes/default-filters.php

@@ -176,7 +176,7 @@ add_action('wp_head', 'wp_print_head_scripts', 9);
 add_action('wp_head', 'wp_generator');
 add_action('wp_footer', 'wp_print_footer_scripts');
 if(!defined('DOING_CRON'))
-	add_action('init', 'wp_cron');
+	add_action('sanitize_comment_cookies', 'wp_cron');
 add_action('do_feed_rdf', 'do_feed_rdf', 10, 1);
 add_action('do_feed_rss', 'do_feed_rss', 10, 1);
 add_action('do_feed_rss2', 'do_feed_rss2', 10, 1);