AC_SUBST(PTHREAD_ONLY)
+dnl =================================================================
+dnl On most platforms select() does not support fd numbers above
+dnl FD_SETSIZE, as a result Privoxy can't handle more than
+dnl approximately FD_SETSIZE/2 client connections.
+dnl On some platforms the value can be changed at compile time,
+dnl on others it's hardcoded and requires recompilation of the OS.
+dnl Only relevant if select() is actually being used.
+dnl =================================================================
+AC_ARG_WITH(fdsetsize,
+ [ --with-fdsetsize=n Optimistically redefine FD_SETSIZE with the intend to change the number of connections Privoxy can handle. Dangerous if the platform doesn't support this. Pointless if Privoxy can use poll() instead of select().],
+ [
+ if test "x$withval" != "xyes"; then
+ AC_DEFINE_UNQUOTED(FD_SETSIZE,$with_fdsetsize,[Relevant for select(). Not honoured by all OS.])
+ echo "Redefining FD_SETSIZE to $with_fdsetsize."
+ AC_MSG_WARN(On platforms that don't support FD_SETSIZE redefinition it may cause memory corruption.)
+ else
+ AC_MSG_ERROR(--with-fdsetsize used without value)
+ fi
+ ]
+)
+
dnl =================================================================
dnl Support for thread-safe versions of gethostbyaddr, gethostbyname,
dnl gmtime and localtime