fballiano-magento-cache-regeneration-lock.patch

From 51dd4b477b7cd11482bcd7bf5334d5825bfb05fa Mon Sep 17 00:00:00 2001
From: Fabrizio Balliano <fabrizio@fabrizioballiano.com>
Date: Tue, 5 Jan 2016 11:26:42 +0000
Subject: [PATCH] added enterprise support

---
 app/code/local/Mage/Core/Model/App.php | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/app/code/local/Mage/Core/Model/App.php b/app/code/local/Mage/Core/Model/App.php
index 56f5765..552935d 100644
--- a/app/code/local/Mage/Core/Model/App.php
+++ b/app/code/local/Mage/Core/Model/App.php
@@ -422,6 +422,38 @@ class Mage_Core_Model_App
     protected function _initModules()
     {
         if (!$this->_config->loadModulesCache()) {
+            //FBALLIANO CACHE GENERATION LOCK START
+            if (Mage::getEdition() == Mage::EDITION_ENTERPRISE) {
+                $resource = new Enterprise_Index_Model_Resource_Lock_Resource();
+                $connection = $resource->getConnection('enterprise_index_write', 'default_lock');
+                $lock = new Enterprise_Index_Model_Resource_Helper_Mysql4("enterprise_index");
+            } else {
+                $resource = new Mage_Index_Model_Resource_Lock_Resource();
+                $connection = $resource->getConnection('index_write', 'default_lock');
+                $lock = new Mage_Index_Model_Resource_Helper_Mysql4("index");
+            }
+            $lock->setWriteAdapter($connection);
+            $loopcounter = 0;
+            while (true) {
+                //try to get the lock. failure means someone else holds the lock
+                if ($lock->setLock("fballiano_cache_regeneration")) {
+                    //perhaps someone else was building cache content while we waited for the lock
+                    //lets see if we can load anything
+                    if ($this->_config->loadModulesCache()) {
+                        $lock->releaseLock("fballiano_cache_regeneration");
+                        return $this;
+                    }
+
+                    //cache was empty or corrupt. proceed to building the cache content
+                    break;
+                }
+                if ($loopcounter++ > 20) {
+                    header("504 Gateway Timeout", true, 504);
+                    die();
+                }
+            }
+            //FBALLIANO CACHE GENERATION LOCK END
+
             $this->_config->loadModules();
             if ($this->_config->isLocalConfigLoaded() && !$this->_shouldSkipProcessModulesUpdates()) {
                 Varien_Profiler::start('mage::app::init::apply_db_schema_updates');
@@ -430,6 +462,10 @@ class Mage_Core_Model_App
             }
             $this->_config->loadDb();
             $this->_config->saveCache();
+
+            //FBALLIANO CACHE GENERATION LOCK START
+            $lock->releaseLock("fballiano_cache_regeneration");
+            //FBALLIANO CACHE GENERATION LOCK END
         }
         return $this;
     }
-- 
2.6.1