improve cron.php, add locking for cli cron.php

diff --git a/cron.php b/cron.php
index f13b284b818d06f504824885798beb16467ccf88..a351572fcda2663ed5a4d052464473de35be001b 100644 (file)
--- a/cron.php
+++ b/cron.php
@@ -23,9 +23,18 @@
 // Unfortunately we need this class for shutdown function
 class my_temporary_cron_class {
        public static $sent = false;
+       public static $lockfile = "";
+       public static $keeplock = false;
 }
 
+// We use this function to handle (unexpected) shutdowns
 function handleUnexpectedShutdown() {
+       // Delete lockfile
+       if( !my_temporary_cron_class::$keeplock && file_exists( my_temporary_cron_class::$lockfile )){
+               unlink( my_temporary_cron_class::$lockfile );
+       }
+       
+       // Say goodbye if the app did not shutdown properly
        if( !my_temporary_cron_class::$sent ) {
                if( OC::$CLI ) {
                        echo 'Unexpected error!'.PHP_EOL;
@@ -48,7 +57,7 @@ if( !OC_Config::getValue( 'installed', false )) {
 register_shutdown_function('handleUnexpectedShutdown');
 
 // Exit if background jobs are disabled!
-$appmode = OC_Appconfig::getValue( 'core', 'backgroundjobs_mode', 'ajax' );
+$appmode = OC_BackgroundJob::getType();
 if( $appmode == 'none' ) {
        my_temporary_cron_class::$sent = true;
        if( OC::$CLI ) {
@@ -61,29 +70,42 @@ if( $appmode == 'none' ) {
 }
 
 if( OC::$CLI ) {
+       // Create lock file first
+       my_temporary_cron_class::$lockfile = OC_Config::getValue( "datadirectory", OC::$SERVERROOT.'/data' ).'/cron.lock';
+       
+       // We call ownCloud from the CLI (aka cron)
        if( $appmode != 'cron' ) {
-               OC_Appconfig::setValue( 'core', 'backgroundjobs_mode', 'cron' );
+               // Use cron in feature!
+               OC_BackgroundJob::setType('cron' );
        }
 
        // check if backgroundjobs is still running
-       $pid = OC_Appconfig::getValue( 'core', 'backgroundjobs_pid', false );
-       if( $pid !== false ) {
-               // FIXME: check if $pid is still alive (*nix/mswin). if so then exit
+       if( file_exists( my_temporary_cron_class::$lockfile )){
+               my_temporary_cron_class::$keeplock = true;
+               my_temporary_cron_class::$sent = true;
+               echo "Another instance of cron.php is still running!";
+               exit( 1 );
        }
-       // save pid
-       OC_Appconfig::setValue( 'core', 'backgroundjobs_pid', getmypid());
+
+       // Create a lock file
+       touch( my_temporary_cron_class::$lockfile );
 
        // Work
        OC_BackgroundJob_Worker::doAllSteps();
 }
 else{
+       // We call cron.php from some website
        if( $appmode == 'cron' ) {
+               // Cron is cron :-P
                OC_JSON::error( array( 'data' => array( 'message' => 'Backgroundjobs are using system cron!')));
        }
        else{
+               // Work and success :-)
                OC_BackgroundJob_Worker::doNextStep();
                OC_JSON::success();
        }
 }
+
+// done!
 my_temporary_cron_class::$sent = true;
 exit();