[COMMITTED] ada: Use CLOCK_MONOTONIC on VxWorks

[COMMITTED] ada: Use CLOCK_MONOTONIC on VxWorks

[Marc Poulhiès]

From: Doug Rupp <rupp@adacore.com>

The monotonic clock keeps track of the time that has elapsed since
system startup; that is, the value returned by clock_gettime() is the
amount of time (in seconds and nanoseconds) that has passed since the
system booted. The monotonic clock cannot be reset. As a result,
time interval measurements made relative to the monotonic clock are
not subject to errors resulting from the clock time being unexpectedly
adjusted between the interval start and end.

gcc/ada/

	* s-oscons-tmplt.c: #define CLOCK_RT_Ada "CLOCK_MONOTONIC" for
	__vxworks

Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/ada/s-oscons-tmplt.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gcc/ada/s-oscons-tmplt.c b/gcc/ada/s-oscons-tmplt.c
index fb6bb0f043b..f1140d5ecbc 100644
--- a/gcc/ada/s-oscons-tmplt.c
+++ b/gcc/ada/s-oscons-tmplt.c
@@ -1975,7 +1975,8 @@ CND(CLOCK_THREAD_CPUTIME_ID, "Thread CPU clock")
 
 #if defined(__linux__) || defined(__FreeBSD__) \
  || (defined(_AIX) && defined(_AIXVERSION_530)) \
- || defined(__DragonFly__) || defined(__QNX__)
+ || defined(__DragonFly__) || defined(__QNX__) \
+ || defined (__vxworks)
 /** On these platforms use system provided monotonic clock instead of
  ** the default CLOCK_REALTIME. We then need to set up cond var attributes
  ** appropriately (see thread.c).
-- 
2.42.0