X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/disorder/blobdiff_plain/05b75f8d50b83e943af3be4071449304d82dbdcd..5f624baebe43889bb2810720cb9cc6d0812f49cb:/lib/timeval.h

diff --git a/lib/timeval.h b/lib/timeval.h
index 10b02ea..e1e64da 100644
--- a/lib/timeval.h
+++ b/lib/timeval.h
@@ -1,27 +1,29 @@
 /*
  * This file is part of DisOrder.
- * Copyright (C) 2007, 2008 Richard Kettlewell
+ * Copyright (C) 2007-2009, 2013 Richard Kettlewell
  *
- * This program is free software; you can redistribute it and/or modify
+ * 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 of the License, or
+ * the Free Software Foundation, either version 3 of the License, 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.
- *
+ * 
+ * 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
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+/** @file lib/timeval.h
+ * @brief Arithmetic on timeval structures
  */
-
 #ifndef TIMEVAL_H
 #define TIMEVAL_H
 
 #include <time.h>
+#include <sys/time.h>
+#include <math.h>
 
 static inline struct timeval tvsub(const struct timeval a,
                                    const struct timeval b) {
@@ -98,6 +100,57 @@ static inline int tvle(const struct timeval *a, const struct timeval *b) {
   return !tvgt(a, b);
 }
 
+/** @brief Return the sum of two timespecs */
+static inline struct timespec tsadd(const struct timespec a,
+                                    const struct timespec b) {
+  struct timespec r;
+
+  r.tv_sec = a.tv_sec + b.tv_sec;
+  r.tv_nsec = a.tv_nsec + b.tv_nsec;
+  if(r.tv_nsec < 0) {
+    r.tv_nsec += 1000000;
+    r.tv_sec--;
+  }
+  if(r.tv_nsec > 999999) {
+    r.tv_nsec -= 1000000;
+    r.tv_sec++;
+  }
+  return r;
+}
+
+/** @brief Subtract one timespec from another */
+static inline struct timespec tssub(const struct timespec a,
+                                    const struct timespec b) {
+  struct timespec r;
+
+  r.tv_sec = a.tv_sec - b.tv_sec;
+  r.tv_nsec = a.tv_nsec - b.tv_nsec;
+  if(r.tv_nsec < 0) {
+    r.tv_nsec += 1000000;
+    r.tv_sec--;
+  }
+  if(r.tv_nsec > 999999) {
+    r.tv_nsec -= 1000000;
+    r.tv_sec++;
+  }
+  return r;
+}
+
+/** @brief Convert a timespec to a double */
+static inline double ts_to_double(const struct timespec ts) {
+  return ts.tv_sec + ts.tv_nsec / 1000000000.0;
+}
+
+/** @brief Convert a double to a timespec */
+static inline struct timespec double_to_ts(double n) {
+  double i, f;
+  struct timespec r;
+  f = modf(n, &i);
+  r.tv_sec = i;
+  r.tv_nsec = 1000000000 * f;
+  return r;
+}
+
 #endif /* TIMEVAL_H */
 
 /*