@Override
 @SuppressWarnings({"unchecked"})
 public int getOrCreate(long o) {
   if (DependencyTracker.isBypassCaches()) {
     return calculatable.calculate(owner, o);
   } else {
     preCheckDirty();
     lock(o);
     try {
       Object v = load(o);
       ExceptionHelper.throwIfExceptionRecordNotExpired(v);
       if (v != UNDEFINED) {
         DependencyTracker.mark(getDependencyNode());
         hit();
         return (Integer) v;
       }
       DependencyNode callerNode = DependencyTracker.track(getDependencyNode());
       try {
         while (true) {
           try {
             return create(o);
           } catch (ResourceOccupied e) {
             if (callerNode != null) {
               throw e;
             } else {
               unlock(o);
               try {
                 e.getResource().waitForEndOfModification();
               } finally {
                 lock(o);
               }
               v = load(o);
               ExceptionHelper.throwIfExceptionRecordNotExpired(v);
               if (v != UNDEFINED) {
                 hit();
                 return (Integer) v;
               }
             }
           }
         }
       } finally {
         DependencyTracker.exit(callerNode);
       }
     } finally {
       unlock(o);
       postCheckDirty();
     }
   }
 }
 @SuppressWarnings({"unchecked"})
 protected int create(long o) {
   long start = System.nanoTime();
   try {
     int retry = 0;
     // retry on exception loop
     while (true) {
       try {
         int t = calculatable.calculate(owner, o);
         // successful invocation => just store the value and return
         save(o, t);
         return t;
       } catch (Exception e) {
         // We catch Exception here, but not Error and not Throwable.
         // this is because in case of Error we are likely have no chance even to save
         // an ExceptionRecord to a storage, so don't even try to do so.
         // For example in case of OOM (out of memory) it may be impossible to create
         // even a single new object.
         CacheExceptionHandler exceptionHandler = getDescriptor().getExceptionHandler();
         switch (exceptionHandler.getAction(retry, e)) {
           case RETRY:
             retry++;
             continue;
           case REMEMBER_AND_RETHROW:
             save(
                 o,
                 new ExceptionRecord(
                     e, exceptionHandler.getRememberExceptionExpirationTimestamp(e)));
             // fall through
           case RETHROW:
           default:
             // this method always throws an exception
             ExceptionHelper.throwCheckedExceptionHack(e);
             break;
         }
       }
     }
   } finally {
     // record calculation time even if calculation fails
     long end = System.nanoTime();
     miss(end - start);
   }
 }