output: #fixed code
                                  public RrdDb requestRrdDb(String path) throws IOException {
  
          RrdEntry ref = null;
          try {
              ref = getEntry(path, true);
          } catch (InterruptedException e) {
              throw new RuntimeException("request interrupted for " + path, e);
          }
  
          //Someone might have already open it, rechecks
          if(ref.count == 0) {
              try {
                  ref.rrdDb = new RrdDb(path);
              } catch (IOException e) {
                  //Don't forget to release the slot reserved earlier
                  usage.decrementAndGet();
                  passNext(ACTION.DROP, ref);
                  throw e;
              }                
          }
          ref.count++;
          passNext(ACTION.SWAP, ref);
          return ref.rrdDb;
      }
input: #vulnerable code 
                                  public RrdDb requestRrdDb(String path) throws IOException {
  
          RrdEntry ref = null;
          try {
              ref = getEntry(path, true);
          } catch (InterruptedException e) {
              throw new RuntimeException("request interrupted for " + path, e);
          }
  
          try {
              //Wait until the pool is not full and 
              //Don't lock on anything
              while(ref.count == 0 && ! tryGetSlot()) {
                  passNext(ACTION.SWAP, ref);
                  countLock.lockInterruptibly();
                  full.await();
                  countLock.unlock();                        
                  ref = getEntry(path, true);
              }
          } catch (InterruptedException e) {
              passNext(ACTION.DROP, ref);
              throw new RuntimeException("request interrupted for " + path, e);
          } finally {
              if(countLock.isHeldByCurrentThread()) {
                  countLock.unlock();                        
              }
          }
          //Someone might have already open it, rechecks
          if(ref.count == 0) {
              try {
                  ref.rrdDb = new RrdDb(path);
              } catch (IOException e) {
                  //Don't forget to release the slot reserved earlier
                  usage.decrementAndGet();
                  passNext(ACTION.DROP, ref);
                  throw e;
              }                
          }
          ref.count++;
          passNext(ACTION.SWAP, ref);
          return ref.rrdDb;
      } 
                              #location 29 
                              #vulnerability type THREAD_SAFETY_VIOLATION