From 2a8927af8f7ed8cd8d279beda1646db2a21859c1 Mon Sep 17 00:00:00 2001
From: Sebastian Grewe <sebastian@grewe.ca>
Date: Fri, 7 Feb 2014 13:00:05 +0100
Subject: [PATCH] [IMPROVED] Check if cron is running in PHP scripts

* Ensures we don't spawn more than one PHP process
* Will require admin-intervention to reset the cron_active flag in DB

Shouldn't trigger often but may help people.
---
 cronjobs/shared.inc.php                     |  5 ++++-
 public/include/classes/monitoring.class.php | 15 +++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/cronjobs/shared.inc.php b/cronjobs/shared.inc.php
index b34026df..a73c5b56 100644
--- a/cronjobs/shared.inc.php
+++ b/cronjobs/shared.inc.php
@@ -82,7 +82,10 @@ if ($monitoring->isDisabled($cron_name)) {
 
 // Mark cron as running for monitoring
 $log->logDebug('Marking cronjob as running for monitoring');
-$monitoring->setStatus($cron_name . '_starttime', 'date', time());
+if (!$monitoring->startCronjob($cron_name)) {
+  $log->logFatal('Unable to start cronjob: ' . $monitoring->getCronError());
+  exit;
+}
 
 // Check if we need to halt our crons due to an outstanding upgrade
 if ($setting->getValue('DB_VERSION') != DB_VERSION || $config['version'] != CONFIG_VERSION) {
diff --git a/public/include/classes/monitoring.class.php b/public/include/classes/monitoring.class.php
index 3cd84cba..b34bd47a 100644
--- a/public/include/classes/monitoring.class.php
+++ b/public/include/classes/monitoring.class.php
@@ -93,6 +93,21 @@ class Monitoring extends Base {
     return false;
   }
 
+  /**
+   * Start a cronjob, mark various fields properly
+   * @param cron_name string Cronjob name
+   **/
+  public function startCronjob($cron_name) {
+    $aStatus = $this->getStatus($cron_name . '_active');
+    if ($aStatus['value'] == 1) {
+      $this->setErrorMessage('Cron is already active in database: ' . $cron_name . '_active is 1');
+      return false;
+    }
+    $this->setStatus($cron_name . "_active", "yesno", 1);
+    $this->setStatus($cron_name . '_starttime', 'date', time());
+    return true;
+  }
+
   /**
    * End cronjob with an error message
    * @param cron_name string Cronjob Name