# define tTHX PerlInterpreter*
#endif
-#if VMG_MULTIPLICITY && defined(dMY_CXT) && defined(MY_CXT) && defined(START_MY_CXT) && defined(MY_CXT_INIT) && (defined(MY_CXT_CLONE) || defined(dMY_CXT_SV))
+#if VMG_MULTIPLICITY && defined(USE_ITHREADS) && defined(dMY_CXT) && defined(MY_CXT) && defined(START_MY_CXT) && defined(MY_CXT_INIT) && (defined(MY_CXT_CLONE) || defined(dMY_CXT_SV))
# define VMG_THREADSAFE 1
# ifndef MY_CXT_CLONE
# define MY_CXT_CLONE \
if (w->cb_copy)
mg->mg_flags |= MGf_COPY;
#endif /* MGf_COPY */
-#if MGf_DUP
+#if 0 /* MGf_DUP */
if (w->cb_dup)
mg->mg_flags |= MGf_DUP;
#endif /* MGf_DUP */
#if MGf_COPY
if (w->cb_copy != NULL) { SvREFCNT_dec(SvRV(w->cb_copy)); }
#endif /* MGf_COPY */
-#if MGf_DUP
+#if 0 /* MGf_DUP */
if (w->cb_dup != NULL) { SvREFCNT_dec(SvRV(w->cb_dup)); }
#endif /* MGf_DUP */
#if MGf_LOCAL