+#ifdef PERL_GLOBAL_STRUCT_PRIVATE
+
+/* This must appear in all extensions that define a my_cxt_t structure,
+ * right after the definition (i.e. at file scope). The non-threads
+ * case below uses it to declare the data as static. */
+#define START_MY_CXT
+#define MY_CXT_INDEX Perl_my_cxt_index(aTHX_ MY_CXT_KEY)
+
+/* Creates and zeroes the per-interpreter data.
+ * (We allocate my_cxtp in a Perl SV so that it will be released when
+ * the interpreter goes away.) */
+#define MY_CXT_INIT \
+ my_cxt_t *my_cxtp = \
+ (my_cxt_t*)Perl_my_cxt_init(aTHX_ MY_CXT_KEY, sizeof(my_cxt_t))
+#define MY_CXT_INIT_INTERP(my_perl) \
+ my_cxt_t *my_cxtp = \
+ (my_cxt_t*)Perl_my_cxt_init(my_perl, MY_CXT_KEY, sizeof(my_cxt_t))
+
+/* This declaration should be used within all functions that use the
+ * interpreter-local data. */
+#define dMY_CXT \
+ my_cxt_t *my_cxtp = (my_cxt_t *)PL_my_cxt_list[MY_CXT_INDEX]
+#define dMY_CXT_INTERP(my_perl) \
+ my_cxt_t *my_cxtp = (my_cxt_t *)(my_perl)->Imy_cxt_list[MY_CXT_INDEX]
+
+/* Clones the per-interpreter data. */
+#define MY_CXT_CLONE \
+ my_cxt_t *my_cxtp = (my_cxt_t*)SvPVX(newSV(sizeof(my_cxt_t)-1));\
+ Copy(PL_my_cxt_list[MY_CXT_INDEX], my_cxtp, 1, my_cxt_t);\
+ PL_my_cxt_list[MY_CXT_INDEX] = my_cxtp \
+
+#else /* #ifdef PERL_GLOBAL_STRUCT_PRIVATE */
+