Index: branches/5.2.x/core/kernel/managers/cache_manager.php
===================================================================
diff -u -N -r14447 -r14560
--- branches/5.2.x/core/kernel/managers/cache_manager.php	(.../cache_manager.php)	(revision 14447)
+++ branches/5.2.x/core/kernel/managers/cache_manager.php	(.../cache_manager.php)	(revision 14560)
@@ -1,6 +1,6 @@
 <?php
 /**
-* @version	$Id: cache_manager.php 14447 2011-07-08 15:43:19Z alex $
+* @version	$Id: cache_manager.php 14560 2011-09-19 21:01:58Z alex $
 * @package	In-Portal
 * @copyright	Copyright (C) 1997 - 2011 Intechnic. All rights reserved.
 * @license      GNU/GPL
@@ -201,14 +201,14 @@
 	 */
 	public function LoadUnitCache()
 	{
-		if ($this->Application->isCachingType(CACHING_TYPE_MEMORY)) {
-			$data = $this->Application->getCache('master:configs_parsed', false);
+		if ( $this->Application->isCachingType(CACHING_TYPE_MEMORY) ) {
+			$data = $this->Application->getCache('master:configs_parsed', false, CacheSettings::$unitCacheRebuildTime);
 		}
 		else {
-			$data = $this->Application->getDBCache('configs_parsed');
+			$data = $this->Application->getDBCache('configs_parsed', CacheSettings::$unitCacheRebuildTime);
 		}
 
-		if ($data) {
+		if ( $data ) {
 			$cache = unserialize($data); // 126 KB all modules
 			unset($data);
 
@@ -230,6 +230,13 @@
 
 		}
 
+		if ( $this->Application->isCachingType(CACHING_TYPE_MEMORY) ) {
+			$this->Application->rebuildCache('master:configs_parsed', kCache::REBUILD_NOW, CacheSettings::$unitCacheRebuildTime);
+		}
+		else {
+			$this->Application->rebuildDBCache('configs_parsed', kCache::REBUILD_NOW, CacheSettings::$unitCacheRebuildTime);
+		}
+
 		return false;
 	}
 
@@ -326,18 +333,18 @@
 	public function DeleteUnitCache($include_sections = false)
 	{
 		if ($this->Application->isCachingType(CACHING_TYPE_MEMORY)) {
-			$this->Application->deleteCache('master:configs_parsed');
+			$this->Application->rebuildCache('master:configs_parsed', kCache::REBUILD_LATER, CacheSettings::$unitCacheRebuildTime);
 		}
 		else {
-			$this->Application->deleteDBCache('configs_parsed');
+			$this->Application->rebuildDBCache('configs_parsed', kCache::REBUILD_LATER, CacheSettings::$unitCacheRebuildTime);
 		}
 
 		if ($include_sections) {
 			if ($this->Application->isCachingType(CACHING_TYPE_MEMORY)) {
-				$this->Application->deleteCache('master:sections_parsed');
+				$this->Application->rebuildCache('master:sections_parsed', kCache::REBUILD_LATER, CacheSettings::$sectionsParsedRebuildTime);
 			}
 			else {
-				$this->Application->deleteDBCache('sections_parsed');
+				$this->Application->rebuildDBCache('sections_parsed', kCache::REBUILD_LATER, CacheSettings::$sectionsParsedRebuildTime);
 			}
 		}
 	}
@@ -447,12 +454,13 @@
 	 *
 	 * @param int $key key name from cache
 	 * @param bool $store_locally store data locally after retrieved
+	 * @param int $max_rebuild_seconds
 	 * @return mixed
 	 * @access public
 	 */
-	public function getCache($key, $store_locally = true)
+	public function getCache($key, $store_locally = true, $max_rebuild_seconds = 0)
 	{
-		return $this->cacheHandler->getCache($key, $store_locally);
+		return $this->cacheHandler->getCache($key, $store_locally, $max_rebuild_seconds);
 	}
 
 	/**
@@ -469,6 +477,18 @@
 	}
 
 	/**
+	 * Sets rebuilding mode for given cache
+	 *
+	 * @param string $name
+	 * @param int $mode
+	 * @param int $max_rebuilding_time
+	 */
+	public function rebuildCache($name, $mode = null, $max_rebuilding_time = 0)
+	{
+		$this->cacheHandler->rebuildCache($name, $mode, $max_rebuilding_time);
+	}
+
+	/**
 	 * Deletes key from cache
 	 *
 	 * @param string $key
@@ -493,11 +513,51 @@
 	 * Returns value from database cache
 	 *
 	 * @param string $name key name
+	 * @param int $max_rebuild_seconds
 	 * @return mixed
 	 * @access public
 	 */
-	public function getDBCache($name)
+	public function getDBCache($name, $max_rebuild_seconds = 0)
 	{
+		if ( $this->_getDBCache($name . '_rebuild') ) {
+			// cache rebuild requested -> rebuild now
+			$this->deleteDBCache($name . '_rebuild');
+
+			return false;
+		}
+
+		// no serials in cache key OR cache is outdated
+		$wait_seconds = $max_rebuild_seconds;
+
+		while (true) {
+			$cache = $this->_getDBCache($name);
+			$rebuilding = $this->_getDBCache($name . '_rebuilding');
+
+			if ( ($cache === false) && (!$rebuilding || $wait_seconds == 0) ) {
+				// cache missing and nobody rebuilding it -> rebuild; enough waiting for cache to be ready
+				return false;
+			}
+			elseif ( $cache !== false ) {
+				// cache present -> return it
+				return $cache;
+			}
+
+			$wait_seconds -= kCache::WAIT_STEP;
+			sleep(kCache::WAIT_STEP);
+		}
+
+		return false;
+	}
+
+	/**
+	 * Returns value from database cache
+	 *
+	 * @param string $name key name
+	 * @return mixed
+	 * @access protected
+	 */
+	protected function _getDBCache($name)
+	{
 		$this->Conn->nextQueryCachable = true;
 
 		$sql = 'SELECT Data, Cached, LifeTime
@@ -529,11 +589,25 @@
 	 *
 	 * @param string $name
 	 * @param mixed $value
-	 * @param int $expiration
+	 * @param int|bool $expiration
 	 * @access public
 	 */
 	public function setDBCache($name, $value, $expiration = false)
 	{
+		$this->deleteDBCache($name . '_rebuilding');
+		$this->_setDBCache($name, $value, $expiration);
+	}
+
+	/**
+	 * Sets value to database cache
+	 *
+	 * @param string $name
+	 * @param mixed $value
+	 * @param int|bool $expiration
+	 * @access protected
+	 */
+	protected function _setDBCache($name, $value, $expiration = false)
+	{
 		if ((int)$expiration <= 0) {
 			$expiration = -1;
 		}
@@ -550,6 +624,25 @@
 	}
 
 	/**
+	 * Sets rebuilding mode for given cache
+	 *
+	 * @param string $name
+	 * @param int $mode
+	 * @param int $max_rebuilding_time
+	 */
+	public function rebuildDBCache($name, $mode = null, $max_rebuilding_time = 0)
+	{
+		if ( !isset($mode) || $mode == kCache::REBUILD_NOW ) {
+			$this->_setDBCache($name . '_rebuilding', 1, $max_rebuilding_time);
+			$this->deleteDBCache($name . '_rebuild');
+		}
+		elseif ( $mode == kCache::REBUILD_LATER ) {
+			$this->_setDBCache($name . '_rebuild', 1, 0);
+			$this->deleteDBCache($name . '_rebuilding');
+		}
+	}
+
+	/**
 	 * Deletes key from database cache
 	 *
 	 * @param string $name