VMS versions prior to 7.0 used localtime internally, and might (or might
not) know the offset from localtime to UTC.
One result is that for Time::Hires on VMS pre-7.0, where the gettimeofday
function isn't defined in the CRTL, we get a test error caused by the
descrepancy between time() [which Perl attempts to adjust to UTC] and
gettimeofday [unadjusted].
This patch adds the adjustment of gettimeofday from local to UTC. It is not
used if the gettimeofday function is present in the CRTL. The code for
doing the adjustments is swiped from VMS.C where all this stuff was
worked out some time ago...
Patch follows.
diff -uBb ext/Time/HiRes/HiRes.xs-orig ext/Time/HiRes/HiRes.xs
--- ext/Time/HiRes/HiRes.xs-orig Mon Oct 8 15:32:35 2001
+++ ext/Time/HiRes/HiRes.xs Mon Oct 8 15:48:12 2001
@@ -94,6 +94,7 @@
#if !defined(HAS_GETTIMEOFDAY) && defined(VMS)
#define HAS_GETTIMEOFDAY
+#include <lnmdef.h>
#include <time.h> /* gettimeofday */
#include <stdlib.h> /* qdiv */
#include <starlet.h> /* sys$gettim */
@@ -122,6 +123,90 @@
static __int64 base_adjust=0;
#endif
+/*
+
+ If we don't have gettimeofday, then likely we are on a VMS machine that
+ operates on local time rather than UTC...so we have to zone-adjust.
+ This code gleefully swiped from VMS.C
+
+*/
+/* method used to handle UTC conversions:
+ * 1 == CRTL gmtime(); 2 == SYS$TIMEZONE_DIFFERENTIAL; 3 == no correction
+ */
+static int gmtime_emulation_type;
+/* number of secs to add to UTC POSIX-style time to get local time */
+static long int utc_offset_secs;
+static struct dsc$descriptor_s fildevdsc =
+ { 12, DSC$K_DTYPE_T, DSC$K_CLASS_S, "LNM$FILE_DEV" };
+static struct dsc$descriptor_s *fildev[] = { &fildevdsc, NULL };
+
+static time_t toutc_dst(time_t loc) {
+ struct tm *rsltmp;
+
+ if ((rsltmp = localtime(&loc)) == NULL) return -1;
+ loc -= utc_offset_secs;
+ if (rsltmp->tm_isdst) loc -= 3600;
+ return loc;
+}
+
+static time_t toloc_dst(time_t utc) {
+ struct tm *rsltmp;
+
+ utc += utc_offset_secs;
+ if ((rsltmp = localtime(&utc)) == NULL) return -1;
+ if (rsltmp->tm_isdst) utc += 3600;
+ return utc;
+}
+
+#define _toutc(secs) ((secs) == (time_t) -1 ? (time_t) -1 : \
+ ((gmtime_emulation_type || timezone_setup()), \
+ (gmtime_emulation_type == 1 ? toutc_dst(secs) : \
+ ((secs) - utc_offset_secs))))
+
+#define _toloc(secs) ((secs) == (time_t) -1 ? (time_t) -1 : \
+ ((gmtime_emulation_type || timezone_setup()), \
+ (gmtime_emulation_type == 1 ? toloc_dst(secs) : \
+ ((secs) + utc_offset_secs))))
+
+static int
+timezone_setup(void)
+{
+ struct tm *tm_p;
+
+ if (gmtime_emulation_type == 0) {
+ int dstnow;
+ time_t base = 15 * 86400; /* 15jan71; to avoid month/year ends between */
+ /* results of calls to gmtime() and localtime() */
+ /* for same &base */
+
+ gmtime_emulation_type++;
+ if ((tm_p = gmtime(&base)) == NULL) { /* CRTL gmtime() is a fake */
+ char off[LNM$C_NAMLENGTH+1];;
+
+ gmtime_emulation_type++;
+ if (!Perl_vmstrnenv("SYS$TIMEZONE_DIFFERENTIAL",off,0,fildev,0)) {
+ gmtime_emulation_type++;
+ utc_offset_secs = 0;
+ Perl_warn(aTHX_ "no UTC offset information; assuming local time is UTC");
+ }
+ else { utc_offset_secs = atol(off); }
+ }
+ else { /* We've got a working gmtime() */
+ struct tm gmt, local;
+
+ gmt = *tm_p;
+ tm_p = localtime(&base);
+ local = *tm_p;
+ utc_offset_secs = (local.tm_mday - gmt.tm_mday) * 86400;
+ utc_offset_secs += (local.tm_hour - gmt.tm_hour) * 3600;
+ utc_offset_secs += (local.tm_min - gmt.tm_min) * 60;
+ utc_offset_secs += (local.tm_sec - gmt.tm_sec);
+ }
+ }
+ return 1;
+}
+
+
int
gettimeofday (struct timeval *tp, void *tpz)
{
@@ -181,6 +266,13 @@
tp->tv_sec = ret;
return -1;
}
+# ifdef VMSISH_TIME
+# ifdef RTL_USES_UTC
+ if (VMSISH_TIME) tp->tv_sec = _toloc(tp->tv_sec);
+# else
+ if (!VMSISH_TIME) tp->tv_sec = _toutc(tp->tv_sec);
+# endif
+# endif
return 0;
}
#endif
--
Drexel University \V --Chuck Lane
======]---------->--------*------------<-------[===========
(215) 895-1545 _/ \ Particle Physics
FAX: (215) 895-5934 /\ /~~~~~~~~~~~ [EMAIL PROTECTED]
