Yup and this is what I have found as an equivalent. Also, saw the same thing happening in coreclr against `gettid` unavailability on SunOS: https://github.com/dotnet/runtime/blob/e6d801722fac7f10181d152115876f235bd69c56/src/coreclr/src/pal/src/include/pal/thread.hpp#L780-L782