From 19f3068ce5d654957f0bc727af8b0d0c7a6b7ba6 Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aschulz@wikimedia.org>
Date: Thu, 20 Nov 2014 00:26:44 -0800
Subject: [PATCH] Made $timeout in BagOStuff::lock() actually work

* Also added a separate $expiry option for things that take a long time

Change-Id: Ie5f81dea031f3c3f3ca8d61ad4cb322a5b876f61
---
 includes/objectcache/BagOStuff.php           | 11 ++++++-----
 includes/objectcache/MultiWriteBagOStuff.php |  5 +++--
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/includes/objectcache/BagOStuff.php b/includes/objectcache/BagOStuff.php
index 1978c3ead3..0a2344688b 100644
--- a/includes/objectcache/BagOStuff.php
+++ b/includes/objectcache/BagOStuff.php
@@ -173,13 +173,14 @@ abstract class BagOStuff {
 
 	/**
 	 * @param string $key
-	 * @param int $timeout [optional]
+	 * @param int $timeout Lock wait timeout [optional]
+	 * @param int $expiry Lock expiry [optional]
 	 * @return bool Success
 	 */
-	public function lock( $key, $timeout = 6 ) {
+	public function lock( $key, $timeout = 6, $expiry = 6 ) {
 		$this->clearLastError();
 		$timestamp = microtime( true ); // starting UNIX timestamp
-		if ( $this->add( "{$key}:lock", 1, $timeout ) ) {
+		if ( $this->add( "{$key}:lock", 1, $expiry ) ) {
 			return true;
 		} elseif ( $this->getLastError() ) {
 			return false;
@@ -198,11 +199,11 @@ abstract class BagOStuff {
 			}
 			usleep( $sleep ); // back off
 			$this->clearLastError();
-			$locked = $this->add( "{$key}:lock", 1, $timeout );
+			$locked = $this->add( "{$key}:lock", 1, $expiry );
 			if ( $this->getLastError() ) {
 				return false;
 			}
-		} while ( !$locked );
+		} while ( !$locked && ( microtime( true ) - $timestamp ) < $timeout );
 
 		return $locked;
 	}
diff --git a/includes/objectcache/MultiWriteBagOStuff.php b/includes/objectcache/MultiWriteBagOStuff.php
index 6a691379a0..c2a4a2783a 100644
--- a/includes/objectcache/MultiWriteBagOStuff.php
+++ b/includes/objectcache/MultiWriteBagOStuff.php
@@ -136,12 +136,13 @@ class MultiWriteBagOStuff extends BagOStuff {
 	/**
 	 * @param string $key
 	 * @param int $timeout
+	 * @param int $expiry
 	 * @return bool
 	 */
-	public function lock( $key, $timeout = 0 ) {
+	public function lock( $key, $timeout = 6, $expiry = 6 ) {
 		// Lock only the first cache, to avoid deadlocks
 		if ( isset( $this->caches[0] ) ) {
-			return $this->caches[0]->lock( $key, $timeout );
+			return $this->caches[0]->lock( $key, $timeout, $expiry );
 		} else {
 			return true;
 		}
-- 
2.20.1