Hey, Reading the latest POSIX description for times(3):
> Upon successful completion, times() shall return the elapsed > real time, in clock ticks, since an arbitrary point in the past > (for example, system start-up time). This point does not change > from one invocation of times() within the process to another. it seems to me that times(3) is meant to return a monotonically increasing value. All other uses I've ever seen don't suggest a different understanding by other application developers. There aren't many left in base, but gnu/usr.bin/gcc/gcc/timevar.c seems to support this. I don't have access to 1003.1-1988 [1] (the most recent standard cited in times.3). Has the description changed much? But, so, with this patch we use CLOCK_MONOTONIC to derive the return value and update the manpage to reflect that. While here, add a RETURN VALUES section like every other library function page and reword things to look like other library function pages (did my best). Attached changes ok? Input on the manpage restructuring/rewording? -- Scott Cheloha [1] It's this, right? https://standards.ieee.org/findstds/standard/1003.1-1988.html Index: lib/libc/gen/times.c =================================================================== RCS file: /cvs/src/lib/libc/gen/times.c,v retrieving revision 1.7 diff -u -p -r1.7 times.c --- lib/libc/gen/times.c 2 Nov 2015 17:02:37 -0000 1.7 +++ lib/libc/gen/times.c 27 Feb 2018 00:44:55 -0000 @@ -28,9 +28,9 @@ * SUCH DAMAGE. */ -#include <sys/time.h> #include <sys/times.h> #include <sys/resource.h> +#include <time.h> /* * Convert usec to clock ticks; could do (usec * CLK_TCK) / 1000000, @@ -42,7 +42,7 @@ clock_t times(struct tms *tp) { struct rusage ru; - struct timeval t; + struct timespec ts; if (getrusage(RUSAGE_SELF, &ru) < 0) return ((clock_t)-1); @@ -52,7 +52,7 @@ times(struct tms *tp) return ((clock_t)-1); tp->tms_cutime = CONVTCK(ru.ru_utime); tp->tms_cstime = CONVTCK(ru.ru_stime); - if (gettimeofday(&t, NULL)) + if (clock_gettime(CLOCK_MONOTONIC, &ts) == -1) return ((clock_t)-1); - return ((clock_t)(CONVTCK(t))); + return (ts.tv_sec * CLK_TCK + ts.tv_nsec / (1000000000 / CLK_TCK)); } Index: lib/libc/gen/times.3 =================================================================== RCS file: /cvs/src/lib/libc/gen/times.3,v retrieving revision 1.14 diff -u -p -r1.14 times.3 --- lib/libc/gen/times.3 17 Jul 2013 05:42:11 -0000 1.14 +++ lib/libc/gen/times.3 27 Feb 2018 00:44:55 -0000 @@ -40,20 +40,14 @@ .Sh DESCRIPTION .Bf -symbolic This interface is obsoleted by -.Xr getrusage 2 +.Xr clock_gettime 2 and -.Xr gettimeofday 2 . +.Xr getrusage 2 . .Ef .Pp The .Fn times -function returns the value of time in -.Dv CLK_TCK Ns s -of a second since -0 hours, 0 minutes, 0 seconds, January 1, 1970, Coordinated Universal -Time (UTC). -.Pp -It also fills in the structure pointed to by +function fills in the structure pointed to by .Fa tp with time-accounting information. .Pp @@ -105,27 +99,33 @@ and elements of the parent when one of the .Xr wait 2 functions returns the process ID of the terminated child to the parent. -If an error occurs, +.Sh RETURN VALUES +Upon successful completion, .Fn times -returns the value +returns the value of real time, +in +.Dv CLK_TCK Ns s +of a second, +elapsed since an arbitrary point in the past. +Otherwise a value of .Li "(clock_t)-1" , -and sets +is returned and the global variable .Va errno -to indicate the error. +is set to indicate the error. .Sh ERRORS The .Fn times -function may fail and set the global variable +function may fail and set .Va errno for any of the errors specified for the library routines -.Xr getrusage 2 +.Xr clock_gettime 2 and -.Xr gettimeofday 2 . +.Xr getrusage 2 . .Sh SEE ALSO .Xr time 1 , +.Xr clock_gettime 2 , .Xr getrusage 2 , -.Xr gettimeofday 2 , .Xr wait 2 .Sh STANDARDS The
