The move-assigning would definitely not be thread-safe.
One possibility would be to wrap the std::unordered_map in a std::shared_ptr, and use the atomic functions for shared_ptr: https://en.cppreference.com/w/cpp/memory/shared_ptr/atomic Regards Antoine. Le 04/01/2019 à 23:17, Wes McKinney a écrit : > hi Gene, > > Yes, feel free to submit a PR to fix this. I would suggest populating > function-local std::unordered_map and then move-assigning it into > name_to_index_ -- I think this should not have race conditions. If you > do want to add a mutex, it could be a static one rather than creating > a new mutex for each StructType > > Thanks > Wes > > On Fri, Jan 4, 2019 at 4:10 PM Gene Novark <g...@pdtpartners.com.invalid> > wrote: >> >> These are both effectively-immutable accessors with lazy initialization. >> However, when accessed from multiple threads a race can occur initializing >> the name_to_index_ map. This seems like a bug rather than a purposeful >> design choice based off the cpp/conventions.rst section on Immutability. I'm >> happy to send a PR if this is agreed to be a bug and what an acceptable fix >> is (e.g. just eagerly initialize, always use a mutex, last-writer-wins with >> some sort of atomic ptr, etc.). >> >> Thanks, >> Gene >> >> >> ________________________________ >> This communication is intended only for the addressee(s), may contain >> confidential, privileged or proprietary information, and may be protected by >> US and other laws. Your acceptance of this communication constitutes your >> agreement to keep confidential all the confidential information contained in >> this communication, as well as any information derived by you from the >> confidential information contained in this communication. We do not waive >> any confidentiality by misdelivery. >> >> If you receive this communication in error, any use, dissemination, printing >> or copying is strictly prohibited; please destroy all electronic and paper >> copies and notify the sender immediately. Nothing in this email is intended >> to constitute (1) investment or trading advice or recommendations or any >> advertisement or (2) a solicitation of an investment in any jurisdiction in >> which such a solicitation would be unlawful. >> >> Please note that PDT Partners, LLC, including its affiliates, reserves the >> right to intercept, archive, monitor and review all communications to and >> from its network.
