Remove the extraneous expire during create, since the subsequent pers…

…ist will obviate it anyway and since keys can expire during a MULTI transaction anyway. Return the removed statement where we always reset the key expiration prior to attempting to obtain a lock. This prevents the orphaned EXISTS key that never expires.

lib/redis/semaphore.rb

@@ -36,7 +36,7 @@ def exists_or_create!
         if token == API_VERSION && @redis.get(version_key).nil?
           @redis.set(version_key, API_VERSION)
         end
-
+        set_expiration_if_necessary
         true
       end
     end
@@ -59,7 +59,6 @@ def delete!
     def lock(timeout = 0)
       exists_or_create!
       release_stale_locks! if check_staleness?
-
       token_pair = @redis.blpop(available_key, timeout)
       return false if token_pair.nil?
 
@@ -157,8 +156,6 @@ def simple_mutex(key_name, expires = nil)
     end
 
     def create!
-      @redis.expire(exists_key, 10)
-
       @redis.multi do
         @redis.del(grabbed_key)
         @redis.del(available_key)
@@ -167,7 +164,6 @@ def create!
         end
         @redis.set(version_key, API_VERSION)
         @redis.persist(exists_key)
-
         set_expiration_if_necessary
       end
     end