# define THREAD_RET_CAST(p) ((void *)(p))
#endif /* THREAD_RET */
+# define LOCK_DOLLARZERO_MUTEX MUTEX_LOCK(&PL_dollarzero_mutex)
+# define UNLOCK_DOLLARZERO_MUTEX MUTEX_UNLOCK(&PL_dollarzero_mutex)
+
#endif /* USE_ITHREADS */
#ifndef MUTEX_LOCK
# define UNLOCK_SV_LOCK_MUTEX
#endif
+#ifndef LOCK_DOLLARZERO_MUTEX
+# define LOCK_DOLLARZERO_MUTEX
+#endif
+
+#ifndef UNLOCK_DOLLARZERO_MUTEX
+# define UNLOCK_DOLLARZERO_MUTEX
+#endif
+
/* THR, SET_THR, and dTHR are there for compatibility with old versions */
#ifndef THR
# define THR PERL_GET_THX