event: implement PollGroup based on Windows select

configure.ac

@@ -170,13 +170,15 @@ AC_ARG_WITH(eventloop,
 
 AC_ARG_WITH(pollmethod,
 	AS_HELP_STRING(
-		[--with-pollmethod=@<:@epoll|auto@:>@],
+		[--with-pollmethod=@<:@epoll|winselect|auto@:>@],
 		[specify poll method for internal event loop (default=auto)]),,
 	[with_pollmethod=auto])
 
 if test "x$with_eventloop" = xauto; then
-	if test "x$enable_epoll" = xyes; then
-		with_eventloop=internal
+	if
+		test "x$enable_epoll" = xyes ||
+		test "x$host_is_windows" = xyes; then
+			with_eventloop=internal
 	else
 		with_eventloop=glib
 	fi
@@ -200,6 +202,8 @@ if test "x$with_eventloop" = xinternal; then
 	if test "x$with_pollmethod" = xauto; then
 		if test "x$enable_epoll" = xyes; then
 			with_pollmethod=epoll
+		elif test "x$host_is_windows" = xyes; then
+			with_pollmethod=winselect
 		else
 			AC_MSG_ERROR([no poll method is available for your platform])
 		fi
@@ -208,6 +212,10 @@ if test "x$with_eventloop" = xinternal; then
 	epoll)
 		AC_DEFINE(USE_EPOLL, 1, [Define to poll sockets with epoll])
 		;;
+	winselect)
+		AC_DEFINE(USE_WINSELECT, 1,
+			[Define to poll sockets with Windows select])
+		;;
 	*)
 		AC_MSG_ERROR([unknown pollmethod option: $with_pollmethod])
 	esac