From 6f76e100383189eb9fd2b861fe2cdba2d94b7c59 Mon Sep 17 00:00:00 2001
From: Klaus Schmidinger <vdr@tvdr.de>
Date: Thu, 27 Dec 2007 15:58:18 +0100
Subject: [PATCH] cTimeMs now uses the monotonic clock, if available

---
 CONTRIBUTORS |  1 +
 HISTORY      |  3 ++-
 Makefile     |  4 ++--
 tools.c      | 37 ++++++++++++++++++++++++++++++++++++-
 4 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index 365e63e2..e7c84d43 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -1943,6 +1943,7 @@ Petri Hintukainen <Petri.Hintukainen@hut.fi>
  for making cRemote::PutMacro() set a lock while it expands the macro
  for pointing out that plugins from cRemote::PutMacro() and cRemote::CallPlugin()
  need to be handled separately
+ for making cTimeMs use the monotonic clock
 
 Marcel Schaeben <mts280@gmx.de>
  for his "Easy Input" patch
diff --git a/HISTORY b/HISTORY
index 0ba9532e..504dabb3 100644
--- a/HISTORY
+++ b/HISTORY
@@ -5529,7 +5529,7 @@ Video Disk Recorder Revision History
 - Fixed stopping live subtitles when a player is attached to the device.
 - Fixed suddenly stopping subtitles in live mode.
 
-2007-11-25: Version 1.5.13
+2007-12-27: Version 1.5.13
 
 - Fixed the declaration of cSubtitleObject::Decode8BppCodeString() (thanks to
   Gregoire Favre).
@@ -5538,3 +5538,4 @@ Video Disk Recorder Revision History
 - The kInfo key is now propagated to any open menu, so that it can react to it
   in a context sensitive manner (suggested by Andreas Brugger). If there is
   no menu open it will show the info of the current broadcast or replay.
+- cTimeMs now uses the monotonic clock, if available (thanks to Petri Hintukainen).
diff --git a/Makefile b/Makefile
index f32773c8..e986dd06 100644
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@
 # See the main source file 'vdr.c' for copyright information and
 # how to reach the author.
 #
-# $Id: Makefile 1.110 2007/11/04 10:15:59 kls Exp $
+# $Id: Makefile 1.111 2007/12/02 11:29:22 kls Exp $
 
 .DELETE_ON_ERROR:
 
@@ -20,7 +20,7 @@ PREFIX  ?= /usr/local
 MANDIR   = $(PREFIX)/share/man
 BINDIR   = $(PREFIX)/bin
 LOCDIR   = ./locale
-LIBS     = -ljpeg -lpthread -ldl -lcap -lfreetype -lfontconfig
+LIBS     = -ljpeg -lpthread -ldl -lcap -lrt -lfreetype -lfontconfig
 INCLUDES = -I/usr/include/freetype2
 
 PLUGINDIR= ./PLUGINS
diff --git a/tools.c b/tools.c
index ba7b0cf9..2f8e0789 100644
--- a/tools.c
+++ b/tools.c
@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: tools.c 1.137 2007/11/03 15:34:07 kls Exp $
+ * $Id: tools.c 1.138 2007/12/27 15:57:49 kls Exp $
  */
 
 #include "tools.h"
@@ -545,6 +545,41 @@ cTimeMs::cTimeMs(int Ms)
 
 uint64_t cTimeMs::Now(void)
 {
+#if _POSIX_TIMERS > 0 && defined(_POSIX_MONOTONIC_CLOCK)
+#define MIN_RESOLUTION 5 // ms
+  static bool initialized = false;
+  static bool monotonic = false;
+  struct timespec tp;
+  if (!initialized) {
+     // check if monotonic timer is available and provides enough accurate resolution:
+     if (clock_getres(CLOCK_MONOTONIC, &tp) == 0) {
+        long Resolution = tp.tv_nsec;
+        // require a minimum resolution:
+        if (tp.tv_sec == 0 && tp.tv_nsec <= MIN_RESOLUTION * 1000000) {
+           if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0) {
+              dsyslog("cTimeMs: using monotonic clock (resolution is %ld ns)", Resolution);
+              monotonic = true;
+              }
+           else
+              esyslog("cTimeMs: clock_gettime(CLOCK_MONOTONIC) failed");
+           }
+        else
+           dsyslog("cTimeMs: not using monotonic clock - resolution is too bad (%ld s %ld ns)", tp.tv_sec, tp.tv_nsec);
+        }
+     else
+        esyslog("cTimeMs: clock_getres(CLOCK_MONOTONIC) failed");
+     initialized = true;
+     }
+  if (monotonic) {
+     if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0)
+        return (uint64_t(tp.tv_sec)) * 1000 + tp.tv_nsec / 1000000;
+     esyslog("cTimeMs: clock_gettime(CLOCK_MONOTONIC) failed");
+     monotonic = false;
+     // fall back to gettimeofday()
+     }
+#else
+#  warning Posix monotonic clock not available
+#endif
   struct timeval t;
   if (gettimeofday(&t, NULL) == 0)
      return (uint64_t(t.tv_sec)) * 1000 + t.tv_usec / 1000;