Merge "Revert "Use display name in category page subheadings if provided""

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

diff --git a/includes/libs/objectcache/BagOStuff.php b/includes/libs/objectcache/BagOStuff.php
index a679be8..d0b68bc 100644 (file)
--- a/includes/libs/objectcache/BagOStuff.php
+++ b/includes/libs/objectcache/BagOStuff.php
@@ -29,6 +29,8 @@
 use Psr\Log\LoggerAwareInterface;
 use Psr\Log\LoggerInterface;
 use Psr\Log\NullLogger;
+use Wikimedia\ScopedCallback;
+use Wikimedia\WaitConditionLoop;
 
 /**
  * interface is intended to be more or less compatible with
@@ -410,35 +412,21 @@ abstract class BagOStuff implements IExpiringStore, LoggerAwareInterface {
                }
 
                $expiry = min( $expiry ?: INF, self::TTL_DAY );
-
-               $this->clearLastError();
-               $timestamp = microtime( true ); // starting UNIX timestamp
-               if ( $this->add( "{$key}:lock", 1, $expiry ) ) {
-                       $locked = true;
-               } elseif ( $this->getLastError() || $timeout <= 0 ) {
-                       $locked = false; // network partition or non-blocking
-               } else {
-                       // Estimate the RTT (us); use 1ms minimum for sanity
-                       $uRTT = max( 1e3, ceil( 1e6 * ( microtime( true ) - $timestamp ) ) );
-                       $sleep = 2 * $uRTT; // rough time to do get()+set()
-
-                       $attempts = 0; // failed attempts
-                       do {
-                               if ( ++$attempts >= 3 && $sleep <= 5e5 ) {
-                                       // Exponentially back off after failed attempts to avoid network spam.
-                                       // About 2*$uRTT*(2^n-1) us of "sleep" happen for the next n attempts.
-                                       $sleep *= 2;
-                               }
-                               usleep( $sleep ); // back off
+               $loop = new WaitConditionLoop(
+                       function () use ( $key, $timeout, $expiry ) {
                                $this->clearLastError();
-                               $locked = $this->add( "{$key}:lock", 1, $expiry );
-                               if ( $this->getLastError() ) {
-                                       $locked = false; // network partition
-                                       break;
+                               if ( $this->add( "{$key}:lock", 1, $expiry ) ) {
+                                       return true; // locked!
+                               } elseif ( $this->getLastError() ) {
+                                       return WaitConditionLoop::CONDITION_ABORTED; // network partition?
                                }
-                       } while ( !$locked && ( microtime( true ) - $timestamp ) < $timeout );
-               }
 
+                               return WaitConditionLoop::CONDITION_CONTINUE;
+                       },
+                       $timeout
+               );
+
+               $locked = ( $loop->invoke() === $loop::CONDITION_REACHED );
                if ( $locked ) {
                        $this->locks[$key] = [ 'class' => $rclass, 'depth' => 1 ];
                }