* modules/gethrxtime: New file.

[gnulib.git] / lib / xtime.h

diff --git a/lib/xtime.h b/lib/xtime.h
new file mode 100644 (file)
index 0000000..333f895
--- /dev/null
+++ b/lib/xtime.h
@@ -0,0 +1,87 @@
+/* xtime -- extended-resolution integer time stamps
+
+   Copyright (C) 2005 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+/* Written by Paul Eggert.  */
+
+#ifndef XTIME_H_
+#define XTIME_H_ 1
+
+/* xtime_t is a signed type used for time stamps.  It is an integer
+   type that is a count of nanoseconds -- except for obsolescent hosts
+   without sufficiently-wide integers, where it is a count of
+   seconds.  */
+#if HAVE_LONG_LONG
+typedef long long int xtime_t;
+# define XTIME_PRECISION 1000000000LL
+#else
+# include <limits.h>
+typedef long int xtime_t;
+# if LONG_MAX >> 31 >> 31 == 0
+#  define XTIME_PRECISION 1L
+# else
+#  define XTIME_PRECISION 1000000000L
+# endif
+#endif
+
+/* Return an extended time value that contains S seconds and NS
+   nanoseconds, without any overflow checking.  */
+static inline xtime_t
+xtime_make (xtime_t s, int ns)
+{
+  if (XTIME_PRECISION == 1)
+    return s;
+  else
+    return XTIME_PRECISION * s + ns;
+}
+
+/* Return the number of seconds in T, which must be nonnegative.  */
+static inline xtime_t
+xtime_nonnegative_sec (xtime_t t)
+{
+  return t / XTIME_PRECISION;
+}
+
+/* Return the number of seconds in T.  */
+static inline xtime_t
+xtime_sec (xtime_t t)
+{
+  return (XTIME_PRECISION == 1
+         ? t
+         : t < 0
+         ? (t + XTIME_PRECISION - 1) / XTIME_PRECISION - 1
+         : xtime_nonnegative_sec (t));
+}
+
+/* Return the number of nanoseconds in T, which must be nonnegative.  */
+static inline int
+xtime_nonnegative_nsec (xtime_t t)
+{
+  return t % XTIME_PRECISION;
+}
+
+/* Return the number of nanoseconds in T.  */
+static inline int
+xtime_nsec (xtime_t t)
+{
+  int ns = t % XTIME_PRECISION;
+  if (ns < 0)
+    ns += XTIME_PRECISION;
+  return ns;
+}
+
+#endif