output: #fixed code
                                  @Override
      public void updateProviders(ProviderGroup providerGroup) {
          checkProviderInfo(providerGroup);
          ProviderGroup oldProviderGroup = addressHolder.getProviderGroup(providerGroup.getName());
          if (ProviderHelper.isEmpty(providerGroup)) {
              addressHolder.updateProviders(providerGroup);
              if (!ProviderHelper.isEmpty(oldProviderGroup)) {
                  if (LOGGER.isWarnEnabled(consumerConfig.getAppName())) {
                      LOGGER.warnWithApp(consumerConfig.getAppName(), "Provider list is emptied, may be all " +
                          "providers has been closed, or this consumer has been add to blacklist");
                      closeTransports();
                  }
              }
          } else {
              addressHolder.updateProviders(providerGroup);
              connectionHolder.updateProviders(providerGroup);
          }
          if (EventBus.isEnable(ProviderInfoUpdateEvent.class)) {
              ProviderInfoUpdateEvent event = new ProviderInfoUpdateEvent(consumerConfig, oldProviderGroup, providerGroup);
              EventBus.post(event);
          }
      }
input: #vulnerable code 
                                  @Override
      public void updateProviders(ProviderGroup providerGroup) {
          checkProviderInfo(providerGroup);
          ProviderGroup oldProviderGroup = addressHolder.getProviderGroup(providerGroup.getName());
          if (ProviderHelper.isEmpty(providerGroup)) {
              addressHolder.updateProviders(providerGroup);
              if (CommonUtils.isNotEmpty(oldProviderGroup.getProviderInfos())) {
                  if (LOGGER.isWarnEnabled(consumerConfig.getAppName())) {
                      LOGGER.warnWithApp(consumerConfig.getAppName(), "Provider list is emptied, may be all " +
                          "providers has been closed, or this consumer has been add to blacklist");
                      closeTransports();
                  }
              }
          } else {
              addressHolder.updateProviders(providerGroup);
              connectionHolder.updateProviders(providerGroup);
          }
          if (EventBus.isEnable(ProviderInfoUpdateEvent.class)) {
              ProviderInfoUpdateEvent event = new ProviderInfoUpdateEvent(consumerConfig, oldProviderGroup, providerGroup);
              EventBus.post(event);
          }
      } 
                              #location 3 
                              #vulnerability type THREAD_SAFETY_VIOLATION