ftp://ftp.ntnu.no/old/pub/X11/R5contrib/xscreensaver-1.17.tar.gz

[xscreensaver] / utils / usleep.c

diff --git a/utils/usleep.c b/utils/usleep.c
new file mode 100644 (file)
index 0000000..2529d57
--- /dev/null
+++ b/utils/usleep.c
@@ -0,0 +1,97 @@
+/* xscreensaver, Copyright (c) 1992 Jamie Zawinski <jwz@lucid.com>
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation.  No representations are made about the suitability of this
+ * software for any purpose.  It is provided "as is" without express or 
+ * implied warranty.
+ */
+
+#if __STDC__
+#include <stdlib.h>
+#endif
+
+#include <X11/Xlib.h>
+#include <X11/Xos.h>   /* lazy way out */
+
+/* usleep() doesn't exist everywhere, and select() is faster anyway.
+ */
+
+#ifndef VMS
+
+#ifdef NO_SELECT
+  /* If you don't have select() or usleep(), I guess you lose...
+     Maybe you have napms() instead?  Let me know.
+   */
+void
+screenhack_usleep (usecs)
+     unsigned long usecs;
+{
+  usleep (usecs);
+}
+
+#else /* ! NO_SELECT */
+
+void
+screenhack_usleep (usecs)
+     unsigned long usecs;
+{
+  struct timeval tv;
+  tv.tv_sec  = usecs / 1000000L;
+  tv.tv_usec = usecs % 1000000L;
+  (void) select (0, 0, 0, 0, &tv);
+}
+
+#endif /* ! NO_SELECT */
+
+#else /* VMS */
+
+#define SEC_DELTA  "0000 00:00:01.00"
+#define TICK_DELTA "0000 00:00:00.08"
+static int bin_sec_delta[2], bin_tick_delta[2], deltas_set = 0;
+
+static void
+set_deltas ()
+{
+  int status;
+  extern int SYS$BINTIM ();
+  $DESCRIPTOR (str_sec_delta,  SEC_DELTA);
+  $DESCRIPTOR (str_tick_delta, TICK_DELTA);
+  if (!deltas_set)
+    {
+      status = SYS$BINTIM (&str_sec_delta, &bin_sec_delta);
+      if (!(status & 1))
+       {
+         fprintf (stderr, "%s: cannot convert delta time ", progname);
+         fprintf (stderr, SEC_DELTA);
+         fprintf (stderr, "; status code = %d\n", status);
+         exit (status);
+       }
+      status = SYS$BINTIM (&str_tick_delta, &bin_tick_delta);
+      if (!(status & 1))
+       {
+         fprintf (stderr, "%s: cannot convert delta time ", progname);
+         fprintf (stderr, TICK_DELTA);
+         fprintf (stderr, "; status code = %d\n", status);
+         exit (status);
+       }
+      deltas_set = 1;
+    }
+}
+
+void
+screenhack_usleep (usecs)
+     unsigned long usecs;
+{
+  int status, *bin_delta;
+  extern int SYS$SCHWDK (), SYS$HIBER (); 
+  
+  if (!deltas_set) set_deltas ();
+  bin_delta = (usecs == TICK_INTERVAL) ? &bin_tick_delta : &bin_sec_delta;
+  status = SYS$SCHDWK (0, 0, bin_delta, 0);
+  if ((status & 1)) (void) SYS$HIBER ();
+}
+
+#endif /*VMS */