# define SET_HIGH_PRIORITY SetPriorityClass(GetCurrentProcess(), REALTIME_PRIORITY_CLASS)
# define UTIL_sleep(s) Sleep(1000*s)
# define UTIL_sleepMilli(milli) Sleep(milli)
-#elif (defined(__unix__) || defined(__unix) || defined(__midipix__) || (defined(__APPLE__) && defined(__MACH__)))
+#elif (defined(__unix__) || defined(__unix) || defined(__VMS) || defined(__midipix__) || (defined(__APPLE__) && defined(__MACH__)))
# include <unistd.h>
# include <sys/resource.h> /* setpriority */
# include <time.h> /* clock_t, nanosleep, clock, CLOCKS_PER_SEC */
-# define SET_HIGH_PRIORITY setpriority(PRIO_PROCESS, 0, -20)
+# if defined(PRIO_PROCESS)
+# define SET_HIGH_PRIORITY setpriority(PRIO_PROCESS, 0, -20)
+# else
+# define SET_HIGH_PRIORITY /* disabled */
+# endif
# define UTIL_sleep(s) sleep(s)
# if defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE >= 199309L)
# define UTIL_sleepMilli(milli) { struct timespec t; t.tv_sec=0; t.tv_nsec=milli*1000000ULL; nanosleep(&t, NULL); }