MINOR: clock: test all clock_gettime() return values

Till now we were only using clock_gettime() for profiling, so if it
would fail it was no big deal. We intend to use it as the main clock
as well now, so we need to more reliably detect its absence or failure
and gracefully fall back to other options. Without the test we would
return anything present in the stack, which is neither clean nor easy
to detect.

diff --git a/src/clock.c b/src/clock.c
index 9a33ee64283568246e6f8962e959e09e16c2994c..9665dfc0ac705b3b6f317c17a44f8658548c1113 100644 (file)
--- a/src/clock.c
+++ b/src/clock.c
@@ -53,10 +53,10 @@ static clockid_t per_thread_clock_id[MAX_THREADS];
 uint64_t now_mono_time(void)
 {
        uint64_t ret = 0;
-#if defined(_POSIX_TIMERS) && defined(_POSIX_TIMERS) && (_POSIX_TIMERS > 0) && defined(_POSIX_MONOTONIC_CLOCK)
+#if defined(_POSIX_TIMERS) && (_POSIX_TIMERS > 0) && defined(_POSIX_MONOTONIC_CLOCK)
        struct timespec ts;
-       clock_gettime(CLOCK_MONOTONIC, &ts);
-       ret = ts.tv_sec * 1000000000ULL + ts.tv_nsec;
+       if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0)
+               ret = ts.tv_sec * 1000000000ULL + ts.tv_nsec;
 #endif
        return ret;
 }
@@ -72,14 +72,13 @@ uint64_t now_mono_time_fast(void)
 #if defined(CLOCK_MONOTONIC_COARSE)
        struct timespec ts;
 
-       clock_gettime(CLOCK_MONOTONIC_COARSE, &ts);
-       return (ts.tv_sec * 1000000000ULL + ts.tv_nsec);
-#else
+       if (clock_gettime(CLOCK_MONOTONIC_COARSE, &ts) == 0)
+               return (ts.tv_sec * 1000000000ULL + ts.tv_nsec);
+#endif
        /* fallback to regular mono time,
         * returns 0 if not supported
         */
        return now_mono_time();
-#endif
 }
 
 /* returns the current thread's cumulated CPU time in nanoseconds if supported, otherwise zero */
@@ -88,8 +87,8 @@ uint64_t now_cpu_time(void)
        uint64_t ret = 0;
 #if defined(_POSIX_TIMERS) && (_POSIX_TIMERS > 0) && defined(_POSIX_THREAD_CPUTIME)
        struct timespec ts;
-       clock_gettime(CLOCK_THREAD_CPUTIME_ID, &ts);
-       ret = ts.tv_sec * 1000000000ULL + ts.tv_nsec;
+       if (clock_gettime(CLOCK_THREAD_CPUTIME_ID, &ts) == 0)
+               ret = ts.tv_sec * 1000000000ULL + ts.tv_nsec;
 #endif
        return ret;
 }
@@ -126,8 +125,8 @@ uint64_t now_cpu_time_thread(int thr)
        uint64_t ret = 0;
 #if defined(_POSIX_TIMERS) && (_POSIX_TIMERS > 0) && defined(_POSIX_THREAD_CPUTIME)
        struct timespec ts;
-       clock_gettime(per_thread_clock_id[thr], &ts);
-       ret = ts.tv_sec * 1000000000ULL + ts.tv_nsec;
+       if (clock_gettime(per_thread_clock_id[thr], &ts) == 0)
+               ret = ts.tv_sec * 1000000000ULL + ts.tv_nsec;
 #endif
        return ret;
 }