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Re: [Minios-devel] [UNIKRAFT/NEWLIB PATCH] Fix remaining time in nanosleep



Hi Dafna,

looking good, thanks for the patch.

On 09/17/2018 09:42 PM, Dafna Hirschfeld wrote:
Add the fix of commit 96f68ab in unikraft to newlib:
Calculate the remaining time to sleep and update
the rem parameter if it is given.
If the remaining time is larger than 0, it means that
the thread was waken up explicitly and nanosleep returns -1
to indicate that. Otherwise nanosleep returns 0.

Signed-off-by: Dafna Hirschfeld <dafna3@xxxxxxxxx>
Reviewed-by: Florian Schmidt <florian.schmidt@xxxxxxxxx>

---
  time.c | 24 +++++++++++++++++++-----
  1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/time.c b/time.c
index 9f12329..16747eb 100644
--- a/time.c
+++ b/time.c
@@ -37,12 +37,12 @@
#include <sys/time.h>
  #include <utime.h>
+#include <uk/plat/time.h>
  #include <uk/config.h>
  #if CONFIG_HAVE_SCHED
  #include <uk/sched.h>
  #else
  #include <uk/plat/lcpu.h>
-#include <uk/plat/time.h>
  #endif
int
@@ -71,9 +71,16 @@ static void __spin_wait(__nsec nsec)
int nanosleep(const struct timespec *req, struct timespec *rem)
  {
-       __nsec nsec = (__nsec) req->tv_sec * 1000000000L;
+       __nsec before, after, diff, nsec;
+ if (!req || req->tv_nsec < 0 || req->tv_nsec > 999999999) {
+               errno = EINVAL;
+               return -1;
+       }
+
+       nsec = (__nsec) req->tv_sec * 1000000000L;
        nsec += req->tv_nsec;
+       before = ukplat_monotonic_clock();
#if CONFIG_HAVE_SCHED
        uk_sched_thread_sleep(nsec);
@@ -81,9 +88,16 @@ int nanosleep(const struct timespec *req, struct timespec 
*rem)
        __spin_wait(nsec);
  #endif
- if (rem) {
-               rem->tv_sec = 0;
-               rem->tv_nsec = 0;
+       after = ukplat_monotonic_clock();
+       diff = after - before;
+
+       if (diff < nsec) {
+               if (rem) {
+                       rem->tv_sec = ukarch_time_nsec_to_sec(nsec - diff);
+                       rem->tv_nsec = ukarch_time_subsec(nsec - diff);
+               }
+               errno = EINTR;
+               return -1;
        }
        return 0;
  }


--
Dr. Florian Schmidt
フローリアン・シュミット
Research Scientist,
Systems and Machine Learning Group
NEC Laboratories Europe
Kurfürsten-Anlage 36, D-69115 Heidelberg
Tel.     +49 (0)6221 4342-265
Fax:     +49 (0)6221 4342-155
e-mail:  florian.schmidt@xxxxxxxxx
============================================================
Registered at Amtsgericht Mannheim, Germany, HRB728558

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