[Git][NTPsec/ntpsec][master] Pull some code out of a time-critical section.

[Eric S. Raymond]

Eric S. Raymond pushed to branch master at NTPsec / ntpsec


Commits:
513edc67 by Eric S. Raymond at 2017-01-25T21:09:53-05:00
Pull some code out of a time-critical section.

- - - - -


1 changed file:

- libntp/systime.c


Changes:

=====================================
libntp/systime.c
=====================================
--- a/libntp/systime.c
+++ b/libntp/systime.c
@@ -355,16 +355,19 @@ step_systime(
 	 * 1969-12-31/23:59:59 UTC and gives us additional two years,
 	 * from the change of NTP era in 2036 to the UNIX rollover in
 	 * 2038. (Minus one second, but that won't hurt.) We *really*
-	 * need a longer 'time_t' after that!  Or a different baseline,
-	 * but that would cause other serious trouble, too.
+	 * need a 64-bit 'time_t' after that!  Or a different
+	 * baseline, but that would cause other serious trouble, too.
+	 *
+	 * 2017 update: The comment above was written before the
+	 * 2008-2009 64-bit transition and assumed a 32-bit time_t
+	 * It now appears much less likely that there still be 
+	 * platforms with 32-bit time running in 2038.
 	 */
 	pivot = 0x7FFFFFFF;
 #endif
 
 	/* get the complete jump distance as l_fp */
-	fp_sys = dtolfp(sys_residual);
-	fp_ofs = dtolfp(step);
-	fp_ofs += fp_sys;
+	fp_ofs = dtolfp(step) + dtolfp(sys_residual);
 
 	/* ---> time-critical path starts ---> */
 
@@ -372,10 +375,6 @@ step_systime(
 	get_ostime(&timets);
 	fp_sys = tspec_stamp_to_lfp(timets);
 
-	/* only used for utmp/wtmpx time-step recording */
-	tslast.tv_sec = timets.tv_sec;
-	tslast.tv_nsec = timets.tv_nsec;
-
 	/* get the target time as l_fp */
 	fp_sys += fp_ofs;
 
@@ -388,7 +387,11 @@ step_systime(
 		return false;
 	}
 
-	/* <--- time-critical path ended with 'ntp_set_tod()' <--- */
+	/* <--- time-critical path ended with call to the settime hook <--- */
+
+	/* only used for utmp/wtmpx time-step recording */
+	tslast.tv_sec = timets.tv_sec;
+	tslast.tv_nsec = timets.tv_nsec;
 
 	sys_residual = 0;
 	lamport_violated = (step < 0);



View it on GitLab: https://gitlab.com/NTPsec/ntpsec/commit/513edc677752ea2d897889ed43ab9aab9157a11d
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