+#if defined(OP_CHECK_MUTEX_LOCK) && defined(OP_CHECK_MUTEX_UNLOCK)
+# define SO_CHECK_MUTEX_LOCK OP_CHECK_MUTEX_LOCK
+# define SO_CHECK_MUTEX_UNLOCK OP_CHECK_MUTEX_UNLOCK
+#else
+# define SO_CHECK_MUTEX_LOCK OP_REFCNT_LOCK
+# define SO_CHECK_MUTEX_UNLOCK OP_REFCNT_UNLOCK
+#endif
+
+typedef OP *(*so_ck_t)(pTHX_ OP *);
+
+#ifdef wrap_op_checker
+
+# define so_ck_replace(T, NC, OCP) wrap_op_checker((T), (NC), (OCP))
+
+#else
+
+STATIC void so_ck_replace(pTHX_ OPCODE type, so_ck_t new_ck, so_ck_t *old_ck_p){
+#define so_ck_replace(T, NC, OCP) so_ck_replace(aTHX_ (T), (NC), (OCP))
+ SO_CHECK_MUTEX_LOCK;
+ if (!*old_ck_p) {
+ *old_ck_p = PL_check[type];
+ PL_check[type] = new_ck;
+ }
+ SO_CHECK_MUTEX_UNLOCK;
+}
+
+#endif
+
+STATIC void so_ck_restore(pTHX_ OPCODE type, so_ck_t *old_ck_p) {
+#define so_ck_restore(T, OCP) so_ck_restore(aTHX_ (T), (OCP))
+ SO_CHECK_MUTEX_LOCK;
+ if (*old_ck_p) {
+ PL_check[type] = *old_ck_p;
+ *old_ck_p = 0;
+ }
+ SO_CHECK_MUTEX_UNLOCK;
+}
+