Index: dmemcache.inc
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/memcache/dmemcache.inc,v
retrieving revision 1.1.2.7
diff -u -p -r1.1.2.7 dmemcache.inc
--- dmemcache.inc       31 Jul 2007 11:29:41 -0000      1.1.2.7
+++ dmemcache.inc       15 Aug 2008 14:17:16 -0000
@@ -62,7 +62,18 @@ function dmemcache_get($key, $bin = 'cac
     $full_key = dmemcache_key($key, $bin);
     $result = $mc->get($full_key);
     if ($result) {
-      $_memcache_statistics['hit'][] = $key;
+      $object_expire_time = $result->expire > 2592000 ? $result->expire :$result->expire + $result->created;
+      $future_expire = time() + 30;
+      // If the object is expiring before the window set aside for regeneration
+      // we try to set a semaphore. If that also succeeds,then we make the
+      // object live just a little bit longer than the semaphore so that it
+      // can't expire while the semaphore is set.
+      if ($result->expire && $object_expire_time <= $future_expire && $mc->add($full_key .'_semaphore', '', FALSE, $future_expire - 1) && $mc->set($full_key, $result, MEMCACHE_COMPRESSED, $future_expire)) {
+        $result = FALSE;
+      }
+      else {
+        $_memcache_statistics['hit'][] = $key;
+      }
     }
     return $result;
   }