ObjFW  Diff

	AS_HELP_STRING([--disable-threads], [disable thread support]))
AS_IF([test x"$enable_threads" != x"no"], [
	AC_MSG_CHECKING(for threads)

	case "$host_os" in
	amigaos* | morphos*)
		AC_MSG_RESULT(Amiga)
		have_amiga_threads="yes"
		;;
	mingw*)
		AC_MSG_RESULT(WinAPI)
		;;
	*)
		AC_MSG_RESULT(POSIX)

	echo "Clang >= 3.2"
	printf "  ** (or the latest Clang release to be able to use all "
	echo "features)."
	echo
])

AS_IF([test x"$enable_threads" != x"no" -a x"$atomic_ops" = x"none" \
    -a x"$have_spinlocks" != x"yes"], [
    -a x"$have_spinlocks" != x"yes" -a x"$have_amiga_threads" != x"yes"], [
	echo
	printf "  ** Warning: You have enabled threads, but neither atomic "
	echo "operations nor"
	printf "  ** spinlocks are available. Expect *very* poor performance, "
	echo "as a mutex will"
	printf "  ** be locked for every retain and release! If you don't "
	echo "need threads, try"
	echo "  ** --disable-threads to work around this problem."
	echo
])