realm/realm-core
src/realm/object-store/CMakeLists.txt
:168
check_symbol_exists(epoll_create sys/epoll.h REALM_HAVE_EPOLL)
check_symbol_exists(epoll_create sys/epoll.h REALM_HAVE_EPOLL)
elseif(REALM_HAVE_EPOLL)
target_compile_definitions(ObjectStore PUBLIC REALM_HAVE_EPOLL=1)