From: Aaron Schulz <aschulz@wikimedia.org>
Date: Thu, 6 Aug 2015 23:08:41 +0000 (-0700)
Subject: Made BagOStuff::merge() avoid retries on I/O errors
X-Git-Tag: 1.31.0-rc.0~10489
X-Git-Url: http://git.cyclocoop.org/%24action?a=commitdiff_plain;h=4065e4d1ab7bb0e1065379d491e3ca050c30ac4d;p=lhc%2Fweb%2Fwiklou.git

Made BagOStuff::merge() avoid retries on I/O errors

Change-Id: Ia2fd61132322ed3fa8909d60d9f7eb42e39cb443
---

diff --git a/includes/libs/objectcache/BagOStuff.php b/includes/libs/objectcache/BagOStuff.php
index 726c789e65..cc07db4453 100644
--- a/includes/libs/objectcache/BagOStuff.php
+++ b/includes/libs/objectcache/BagOStuff.php
@@ -142,11 +142,17 @@ abstract class BagOStuff implements LoggerAwareInterface {
 	 */
 	protected function mergeViaCas( $key, $callback, $exptime = 0, $attempts = 10 ) {
 		do {
+			$this->clearLastError();
 			$casToken = null; // passed by reference
 			$currentValue = $this->get( $key, $casToken );
+			if ( $this->getLastError() ) {
+				return false; // don't spam retries (retry only on races)
+			}
+
 			// Derive the new value from the old value
 			$value = call_user_func( $callback, $this, $key, $currentValue );
 
+			$this->clearLastError();
 			if ( $value === false ) {
 				$success = true; // do nothing
 			} elseif ( $currentValue === false ) {
@@ -156,6 +162,9 @@ abstract class BagOStuff implements LoggerAwareInterface {
 				// Try to update the key, failing if it gets changed in the meantime
 				$success = $this->cas( $casToken, $key, $value, $exptime );
 			}
+			if ( $this->getLastError() ) {
+				return false; // IO error; don't spam retries
+			}
 		} while ( !$success && --$attempts );
 
 		return $success;
@@ -189,14 +198,17 @@ abstract class BagOStuff implements LoggerAwareInterface {
 			return false;
 		}
 
+		$this->clearLastError();
 		$currentValue = $this->get( $key );
-		// Derive the new value from the old value
-		$value = call_user_func( $callback, $this, $key, $currentValue );
+		if ( !$this->getLastError() ) {
+			// Derive the new value from the old value
+			$value = call_user_func( $callback, $this, $key, $currentValue );
 
-		if ( $value === false ) {
-			$success = true; // do nothing
-		} else {
-			$success = $this->set( $key, $value, $exptime ); // set the new value
+			if ( $value === false ) {
+				$success = true; // do nothing
+			} else {
+				$success = $this->set( $key, $value, $exptime ); // set the new value
+			}
 		}
 
 		if ( !$this->unlock( $key ) ) {