Boost C++ Libraries: Ticket #11398: boost log should allow setting BOOST_LOG_EVENT_USE_BOOST_CONDITION manually

Mathias Gaunard — Mon, 15 Jun 2015 10:03:20 GMT

Pull request here:

Andrey Semashev — Mon, 15 Jun 2015 14:36:31 GMT

I don't want to make BOOST_LOG_EVENT_USE_BOOST_CONDITION a public macro. The long term plan is to remove event implementation from Boost.Log and move to Boost.Sync. Until that happens, I could use Boost.Atomic for atomic ops instead of __sync* intrinsics directly. I believe, lack of those intrinsics in gcc 4.1 is what makes the condition variable version to be selected?

BTW, ABI compatibility between different compilers is not guaranteed - not only because Boost.Log can contain different versions of the code (like in the case of event) but because this can be the case in other libraries.

Mathias Gaunard — Mon, 15 Jun 2015 18:46:02 GMT

GCC has had a stable ABI since 4.0. Since it has many versions, it is very common for libraries that are shipped in binary form to be linked against code that uses a different version of GCC. Boost.Log is the only Boost library with this issue as far as I know, and the fix is quite simple, so I don't see a good reason not to include it if it fixes real deployment problems in the industry.

Arguably a better fix would be to have a sane ABI that doesn't change depending on compiler version, but that's more work.

status changed; resolution set

Andrey Semashev — Sun, 05 Jul 2015 19:04:36 GMT

status new → closed
resolution → fixed

Done in https://github.com/boostorg/log/commit/30e7f036316d20285f8cecea36ca6a8ac0190125. BOOST_LOG_EVENT_USE_BOOST_CONDITION is still a private macro, it should not be used by users.