boost::lockfree should use BOOST_LIKELY/UNLIKELY macros instead of defining likely/unlikely as inline fns

[Sampath Tilakumara <sampath@…>]

Currently boost::lockfree defines unlikely/unlikely inline functions in branch_hints.hpp. This name is generic and causes conflicts with other (external) libs which also defines likely/unlikely. (linux kernel also defines them the same). boost already has macros defined for this as BOOST_LIKELY/UNLIKELY in boost/config.hpp, and lockfree should use these to avoid conflicts and to be consistent.

The following changes were done in boost_1_58_0, and tested to avoid a conflict case.

* Comment out the following lines: (not required; those files don’t use likely/unlikely)
detail/tagged_ptr_dcas.hpp:#include <boost/lockfree/detail/branch_hints.hpp>
detail/tagged_ptr_ptrcompression.hpp:#include <boost/lockfree/detail/branch_hints.hpp>

* Replace the following include line with “#include <boost/config.hpp> // for BOOST_LIKELY”
spsc_queue.hpp:#include <boost/lockfree/detail/branch_hints.hpp>

* Add “#include <boost/config.hpp> // for BOOST_LIKELY” to queue.hpp

* Change the following likely/unlikely to BOOST_LIKELY/BOOST_UNLIKELY
queue.hpp:        using detail::likely;
queue.hpp:            if (likely(tail == tail2)) {
queue.hpp:        using detail::likely;
queue.hpp:            if (likely(head == head2)) {
spsc_queue.hpp:        while (unlikely(ret >= max_size))

* note that this makes the branch_hints.hpp redundant.

[Sampath Tilakumara <sampath@…>]

Note that the mentioned changes were done in a "local copy" of boost_1_58_0; not committed to boost.

[timblechmann]

could you submit a pull request on github?

thnx, tim

[Sampath Tilakumara <sampath@…>]

Pull request submitted. ​https://github.com/wolfie2x/lockfree/commit/14039a027433a0a9d6b5f7bfd7b54c157997ea90

Let me know if there's anything more I could do.