timer: Add compatibility header with timer helpers

Some of these are not always present, especially when cross compiling

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>

include/osmocom/core/Makefile.am

@@ -6,6 +6,8 @@ osmocore_HEADERS = signal.h linuxlist.h timer.h select.h msgb.h bits.h \
 		   backtrace.h conv.h application.h \
 		   crcgen.h crc8gen.h crc16gen.h crc32gen.h crc64gen.h
 
+noinst_HEADERS = timer_compat.h
+
 if ENABLE_PLUGIN
 osmocore_HEADERS += plugin.h
 endif

include/osmocom/core/timer_compat.h

@@ -0,0 +1,79 @@
+/*
+ * (C) 2011 Sylvain Munaut <tnt@246tNt.com>
+ * All Rights Reserved
+ *
+ * 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
+ * (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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+/*! \defgroup timer Osmocom timers
+ *  @{
+ */
+
+/*! \file timer_compat.h
+ *  \brief Compatibility header with some helpers
+ */
+
+#ifndef TIMER_COMPAT_H
+#define TIMER_COMPAT_H
+
+
+/* Convenience macros for operations on timevals.
+   NOTE: `timercmp' does not work for >= or <=.  */
+
+#ifndef timerisset
+# define timerisset(tvp)	((tvp)->tv_sec || (tvp)->tv_usec)
+#endif
+
+#ifndef timerclear
+# define timerclear(tvp)	((tvp)->tv_sec = (tvp)->tv_usec = 0)
+#endif
+
+#ifndef timercmp
+# define timercmp(a, b, CMP) 						      \
+  (((a)->tv_sec == (b)->tv_sec) ? 					      \
+   ((a)->tv_usec CMP (b)->tv_usec) : 					      \
+   ((a)->tv_sec CMP (b)->tv_sec))
+#endif
+
+#ifndef timeradd
+# define timeradd(a, b, result)						      \
+  do {									      \
+    (result)->tv_sec = (a)->tv_sec + (b)->tv_sec;			      \
+    (result)->tv_usec = (a)->tv_usec + (b)->tv_usec;			      \
+    if ((result)->tv_usec >= 1000000)					      \
+      {									      \
+	++(result)->tv_sec;						      \
+	(result)->tv_usec -= 1000000;					      \
+      }									      \
+  } while (0)
+#endif
+
+#ifndef timersub
+# define timersub(a, b, result)						      \
+  do {									      \
+    (result)->tv_sec = (a)->tv_sec - (b)->tv_sec;			      \
+    (result)->tv_usec = (a)->tv_usec - (b)->tv_usec;			      \
+    if ((result)->tv_usec < 0) {					      \
+      --(result)->tv_sec;						      \
+      (result)->tv_usec += 1000000;					      \
+    }									      \
+  } while (0)
+#endif
+
+
+/*! }@ */
+
+#endif /* TIMER_COMPAT_H */

src/timer.c

@@ -38,6 +38,7 @@ static struct timeval *nearest_p;
 #include <string.h>
 #include <limits.h>
 #include <osmocom/core/timer.h>
+#include <osmocom/core/timer_compat.h>
 #include <osmocom/core/linuxlist.h>
 
 static struct rb_root timer_root = RB_ROOT;