1 files changed, 11 insertions, 5 deletions

diff --git a/cpukit/posix/src/clocknanosleep.c b/cpukit/posix/src/clocknanosleep.c
index 3fa890fecd..43f15346de 100644
--- a/cpukit/posix/src/clocknanosleep.c
+++ b/cpukit/posix/src/clocknanosleep.c
@@ -82,6 +82,15 @@ int clock_nanosleep(
     rmtp = NULL;
   } else {
     absolute = false;
+
+    /*
+     * A relative CLOCK_REALTIME time out shall not be affected by
+     * CLOCK_REALTIME changes through clock_settime().  Since our
+     * CLOCK_REALTIME is basically just CLOCK_MONOTONIC plus an offset, we can
+     * simply use the CLOCK_MONOTONIC watchdog for relative CLOCK_REALTIME time
+     * outs.
+     */
+    clock_id = CLOCK_MONOTONIC;
   }
 
   if ( clock_id == CLOCK_REALTIME ) {
@@ -118,11 +127,8 @@ int clock_nanosleep(
       struct timespec actual_end;
       struct timespec planned_end;
 
-      if ( clock_id == CLOCK_REALTIME ) {
-        _Timecounter_Nanotime( &actual_end );
-      } else {
-        _Timecounter_Nanouptime( &actual_end );
-      }
+      _Assert( clock_id == CLOCK_MONOTONIC );
+      _Timecounter_Nanouptime( &actual_end );
 
       _Watchdog_Ticks_to_timespec(
         executing->Timer.Watchdog.expire,