diff options
| -rw-r--r-- | lib/xnanosleep.c | 27 |
1 files changed, 19 insertions, 8 deletions
diff --git a/lib/xnanosleep.c b/lib/xnanosleep.c index e6289fe68..8f9eb7e25 100644 --- a/lib/xnanosleep.c +++ b/lib/xnanosleep.c @@ -24,6 +24,7 @@ #include <stdio.h> #include <assert.h> +#include <errno.h> #include <sys/types.h> #include <time.h> @@ -123,7 +124,8 @@ clock_get_realtime (struct timespec *ts) SECONDS seconds after the time this function is called. SECONDS must be non-negative. If SECONDS is so large that it is not representable as a `struct timespec', then use - the maximum value for that interval. */ + the maximum value for that interval. Return -1 on failure + (setting errno), 0 on success. */ int xnanosleep (double seconds) @@ -147,7 +149,7 @@ xnanosleep (double seconds) #endif if (clock_get_realtime (&ts_start) == NULL) - return 1; + return -1; /* Separate whole seconds from nanoseconds. Be careful to detect any overflow. */ @@ -193,13 +195,22 @@ xnanosleep (double seconds) ts_sleep.tv_nsec = ts_stop.tv_nsec = 999999999; } - /* In case this process is suspended, then resumed, we'll know - whether to resume sleeping. */ - while (nanosleep (&ts_sleep, NULL) != 0 - && timespec_subtract (&ts_sleep, &ts_stop, - clock_get_realtime (&ts_start))) + while (nanosleep (&ts_sleep, NULL) != 0) { - continue; + if (errno != EINTR) + return -1; + + /* POSIX.1-2001 requires that when a process is suspended, then + resumed, nanosleep (A, B) returns -1, sets errno to EINTR, + and sets *B to the time remaining at the point of resumption. + However, some versions of the Linux kernel incorrectly return + the time remaining at the point of suspension. Work around + this bug by computing the remaining time here, rather than by + relying on nanosleep's computation. */ + + if (! timespec_subtract (&ts_sleep, &ts_stop, + clock_get_realtime (&ts_start))) + break; } return 0; |