+
+/* these record the best way to to perform certain IO operations while
+ * atomically setting FD_CLOEXEC. On the first call, a probe is done
+ * and the result recorded for use by subsequent calls.
+ * In theory these variables aren't thread-safe, but the worst that can
+ * happen is that two treads will both do an initial probe
+ */
+PERLVARI(G, strategy_dup, int, 0) /* doio.c */
+PERLVARI(G, strategy_dup2, int, 0) /* doio.c */
+PERLVARI(G, strategy_open, int, 0) /* doio.c */
+PERLVARI(G, strategy_open3, int, 0) /* doio.c */
+PERLVARI(G, strategy_mkstemp, int, 0) /* doio.c */
+PERLVARI(G, strategy_socket, int, 0) /* doio.c */
+PERLVARI(G, strategy_accept, int, 0) /* doio.c */
+PERLVARI(G, strategy_pipe, int, 0) /* doio.c */
+PERLVARI(G, strategy_socketpair, int, 0) /* doio.c */
+
+#ifdef PERL_IMPLICIT_CONTEXT
+# ifdef PERL_GLOBAL_STRUCT_PRIVATE
+/* per-module array of pointers to MY_CXT_KEY constants.
+ * It simulates each module having a static my_cxt_index var on builds
+ * which don't allow static vars */
+PERLVARI(G, my_cxt_keys, const char **, NULL)
+PERLVARI(G, my_cxt_keys_size, int, 0) /* size of PL_my_cxt_keys */
+# endif
+#endif