On 20 October 2013 20:32, Keith Erickson wrote: > Calling std::this_thread::yield on g++ 4.8.1 doesn't actually result > in a call to the underlying pthread_yield or linux sched_yield. I > eventually found this to be related to a define: > _GLIBCXX_USE_SCHED_YIELD. How do I get that set, though? Is it > something I can define inside my program, or do I really have to go > and recompile the whole toolchain just to be able to use a basic > concurrency function? Technically you need to rebuild GCC (not the whole toolchain) with --enable-libstdcxx-time, see http://stackoverflow.com/a/12961816/981959 for more details. You shouldn't define the macro in your program as it's an internal detail of the library, but since it only affects header-only code not anything compiled into the library, you can get away with defining it. A cleaner alternative is suggested at http://stackoverflow.com/a/9140270/981959
