I'm surprised that the C++ code is not using the RAII idiom in some obvious places.

For example: https://github.com/facebook/rocksdb/blob/master/db/db_impl.c

There are many places with bracketed calls to mutex_.Lock and mutex_.Unlock().

An example:

      mutex_.Unlock();
      LogFlush(options_.info_log);
      env_->SleepForMicroseconds(1000000);
      mutex_.Lock()

Why didn't the authors use the RAII idiom here? Even if there are no exceptions expected, the code would still be simpler and less error prone by using a guard object.