         if reader.sem.setState(.Invalidated) { reader.sem.signal(); break }
 
       default:
-        assertionFailure("Unexpected case \(reader.sem.state.rawValue) in \(__FUNCTION__)")
+        continue
       }
     }
     while let writer = writerQueue.dequeue()

          }

        default:
          assertionFailure("Unexpected case \(reader.sem.state.rawValue) in \(__FUNCTION__)")
        }
      }
      OSSpinLockUnlock(&lock)

          }

        default:
          continue
        }
      }
      while (nextput &- head) < capacity || closed, let writer = writerQueue.dequeue()
