diff options
Diffstat (limited to 'tests/clock-back.c')
| -rw-r--r-- | tests/clock-back.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/tests/clock-back.c b/tests/clock-back.c index 50870ca..2ab83e0 100644 --- a/tests/clock-back.c +++ b/tests/clock-back.c @@ -1,8 +1,12 @@ #define _GNU_SOURCE -/* LD_PRELOAD: the wall clock (CLOCK_REALTIME) set back an hour from - * CLOCK_BACK_MS milliseconds (200 unless given) after the process first - * asks for it, as a person or NTP may set it. A program's timers must go on - * all the same: they wait on the monotonic clock (tests/check.py). */ +/* LD_PRELOAD: the wall clock (CLOCK_REALTIME) set back an hour (moved + * CLOCK_SHIFT_S seconds: -3600 unless given) from CLOCK_BACK_MS milliseconds + * (200 unless given) after the process first asks for it, as a person or NTP + * may set it. Only what the process reads moves, so a wait until a deadline + * read from the wall clock ends at once (set back) or lasts an hour (set + * forward), as one would with the clock set the other way after it was read. + * A program's timers and waits must go on all the same: they count on the + * monotonic clock (tests/check.py). */ #include <dlfcn.h> #include <stdlib.h> #include <time.h> @@ -17,7 +21,7 @@ int clock_gettime(clockid_t id, struct timespec *t) { real(CLOCK_MONOTONIC, &now); long long ms = (long long)now.tv_sec * 1000 + now.tv_nsec / 1000000; if (began < 0) began = ms; - const char *after = getenv("CLOCK_BACK_MS"); - if (ms - began >= (after ? atoll(after) : 200)) t->tv_sec -= 3600; + const char *after = getenv("CLOCK_BACK_MS"), *shift = getenv("CLOCK_SHIFT_S"); + if (ms - began >= (after ? atoll(after) : 200)) t->tv_sec += shift ? atoll(shift) : -3600; return result; } |