Adjust clock sleep based on schedule processing.

lib/sidetiq/clock.rb

@@ -160,11 +160,20 @@ module Sidetiq
 
     def clock
       loop do
-        yield
+        sleep_time = time { yield }
+
+        if sleep_time > 0
           Thread.pass
-        sleep Sidetiq.config.resolution
+          sleep sleep_time
         end
       end
     end
+
+    def time
+      start = gettime
+      yield
+      Sidetiq.config.resolution - (gettime.to_f - start.to_f)
+    end
+  end
 end