diff options
Diffstat (limited to 'src/sleep.c')
| -rw-r--r-- | src/sleep.c | 70 |
1 files changed, 53 insertions, 17 deletions
diff --git a/src/sleep.c b/src/sleep.c index 3947a302c..9d96e3983 100644 --- a/src/sleep.c +++ b/src/sleep.c @@ -36,6 +36,13 @@ #include "long-options.h" #include "xstrtod.h" +#if HAVE_FENV_H +# include <fenv.h> +#endif +#if 199901 <= __STDC_VERSION__ + #pragma STDC FENV_ACCESS ON +#endif + /* The official name of this program (e.g., no `g' prefix). */ #define PROGRAM_NAME "sleep" @@ -81,8 +88,6 @@ apply_suffix (double *s, char suffix_char) { unsigned int multiplier; - assert (*s <= TIME_T_MAX); - switch (suffix_char) { case 0: @@ -148,7 +153,7 @@ clock_get_realtime (struct timespec *ts) { int fail; #if USE_CLOCK_GETTIME - fail = clock_gettime (CLOCK_REALTIME, &ts); + fail = clock_gettime (CLOCK_REALTIME, ts); #else struct timeval tv; fail = gettimeofday (&tv, NULL); @@ -168,8 +173,10 @@ main (int argc, char **argv) { int i; double seconds = 0.0; + double ns; int c; int fail = 0; + int forever; struct timespec ts_start; struct timespec ts_stop; struct timespec ts_sleep; @@ -203,38 +210,56 @@ main (int argc, char **argv) usage (1); } +#ifdef FE_UPWARD + /* Always round up, since we must sleep for at least the specified + interval. */ + fesetround (FE_UPWARD); +#endif + for (i = optind; i < argc; i++) { double s; const char *p; if (xstrtod (argv[i], &p, &s) - /* No negative intervals. */ - || s < 0 - /* S must fit in a time_t. */ - || TIME_T_MAX < s + /* Nonnegative interval. */ + || ! (0 <= s) /* No extra chars after the number and an optional s,m,h,d char. */ || (*p && *(p+1)) /* Check any suffix char and update S based on the suffix. */ - || apply_suffix (&s, *p) - /* Make sure the sum fits in a time_t. */ - || TIME_T_MAX < (seconds += s) - ) + || apply_suffix (&s, *p)) { error (0, 0, _("invalid time interval `%s'"), argv[i]); fail = 1; } + + seconds += s; } if (fail) usage (1); - /* Add this here so we end up rounding to the nearest nanosecond. - This ensures that that tv_nsec will be no larger than 999,999,999. */ - seconds += .0000000005; - - /* Separate whole seconds from nanoseconds. */ + /* Separate whole seconds from nanoseconds. + Be careful to detect any overflow. */ ts_sleep.tv_sec = seconds; - ts_sleep.tv_nsec = (seconds - ts_sleep.tv_sec) * 1000000000; + ns = 1e9 * (seconds - ts_sleep.tv_sec); + forever = ! (ts_sleep.tv_sec <= seconds && 0 <= ns && ns <= 1e9); + ts_sleep.tv_nsec = ns; + + /* Round up to the next whole number, if necessary, so that we + always sleep for at least the request amount of time. */ + ts_sleep.tv_nsec += (ts_sleep.tv_nsec < ns); + + /* Normalize the interval length. nanosleep requires this. */ + if (1000000000 <= ts_sleep.tv_nsec) + { + time_t t = ts_sleep.tv_sec + 1; + + /* Detect floating point overflow (NaN) in interval length. */ + forever |= (t < ts_sleep.tv_sec); + + ts_sleep.tv_sec = t; + ts_sleep.tv_nsec -= 1000000000; + } ts_stop.tv_sec = ts_start.tv_sec + ts_sleep.tv_sec; ts_stop.tv_nsec = ts_start.tv_nsec + ts_sleep.tv_nsec; @@ -244,6 +269,17 @@ main (int argc, char **argv) ts_stop.tv_nsec -= 1000000000; } + /* Detect integer overflow. */ + forever |= (ts_stop.tv_sec < ts_start.tv_sec + || (ts_stop.tv_sec == ts_start.tv_sec + && ts_stop.tv_nsec < ts_start.tv_nsec)); + + if (forever) + { + ts_sleep.tv_sec = ts_stop.tv_sec = TIME_T_MAX; + ts_sleep.tv_nsec = ts_stop.tv_nsec = 999999999; + } + while (1) { struct timespec remaining; |