Made BagOStuff fail fast in cas/lock on certain errors

[lhc/web/wiklou.git] / includes / objectcache / BagOStuff.php

diff --git a/includes/objectcache/BagOStuff.php b/includes/objectcache/BagOStuff.php
index 217142c..ad3aa96 100644 (file)
--- a/includes/objectcache/BagOStuff.php
+++ b/includes/objectcache/BagOStuff.php
@@ -43,6 +43,14 @@
 abstract class BagOStuff {
        private $debugMode = false;
 
+       protected $lastError = self::ERR_NONE;
+
+       /** Possible values for getLastError() */
+       const ERR_NONE        = 0; // no error
+       const ERR_NO_RESPONSE = 1; // no response
+       const ERR_UNREACHABLE = 2; // can't connect
+       const ERR_UNEXPECTED  = 3; // response gave some error
+
        /**
         * @param $bool bool
         */
@@ -169,9 +177,12 @@ abstract class BagOStuff {
         * @return bool success
         */
        public function lock( $key, $timeout = 6 ) {
+               $this->clearLastError();
                $timestamp = microtime( true ); // starting UNIX timestamp
                if ( $this->add( "{$key}:lock", 1, $timeout ) ) {
                        return true;
+               } elseif ( $this->getLastError() ) {
+                       return false;
                }
 
                $uRTT = ceil( 1e6 * ( microtime( true ) - $timestamp ) ); // estimate RTT (us)
@@ -186,7 +197,11 @@ abstract class BagOStuff {
                                $sleep *= 2;
                        }
                        usleep( $sleep ); // back off
+                       $this->clearLastError();
                        $locked = $this->add( "{$key}:lock", 1, $timeout );
+                       if ( $this->getLastError() ) {
+                               return false;
+                       }
                } while ( !$locked );
 
                return $locked;
@@ -292,6 +307,32 @@ abstract class BagOStuff {
                return $this->incr( $key, - $value );
        }
 
+       /**
+        * Get the "last error" registered; clearLastError() should be called manually
+        * @return integer ERR_* constant for the "last error" registry
+        * @since 1.23
+        */
+       public function getLastError() {
+               return $this->lastError;
+       }
+
+       /**
+        * Clear the "last error" registry
+        * @since 1.23
+        */
+       public function clearLastError() {
+               $this->lastError = self::ERR_NONE;
+       }
+
+       /**
+        * Set the "last error" registry
+        * @param $err integer ERR_* constant
+        * @since 1.23
+        */
+       protected function setLastError( $err ) {
+               $this->lastError = $err;
+       }
+
        /**
         * @param $text string
         */