Upgrade to Time::HiRes 1.59.

p4raw-id: //depot/perl@22680

3 files changed, 25 insertions, 8 deletions

diff --git a/ext/Time/HiRes/Changes b/ext/Time/HiRes/Changes
index 33194b7754..7b64ee1a6c 100644
--- a/ext/Time/HiRes/Changes
+++ b/ext/Time/HiRes/Changes
@@ -1,8 +1,17 @@
 Revision history for Perl extension Time::HiRes.
 
+1.59
+	- Change the Win32 recalibration limit to 0.5 seconds and tweak
+	  the documentation to blather less about the gory details of the
+	  Win32 implementation and more about the complications in general
+	  of meddling with the system clock.
+
+1.58
+	- Document the 1.57 change better.
+
 1.57
-	- Window/Cygwin: if the performance counter drifts by more than
-	  two seconds from the system clock (due to ntp adjustments,
+	- Win32/Cygwin/MinGW: if the performance counter drifts by more
+	  than two seconds from the system clock (due to ntp adjustments,
 	  for example), recalibrate our internal counter: from Jan Dubois,
 	  based on [cpan #5933] by Jerry D. Hedden.
 
diff --git a/ext/Time/HiRes/HiRes.pm b/ext/Time/HiRes/HiRes.pm
index b6c87474cf..98d314297b 100644
--- a/ext/Time/HiRes/HiRes.pm
+++ b/ext/Time/HiRes/HiRes.pm
@@ -15,7 +15,7 @@ require DynaLoader;
 		 d_usleep d_ualarm d_gettimeofday d_getitimer d_setitimer
 		 d_nanosleep);
 	
-$VERSION = '1.57';
+$VERSION = '1.59';
 $XS_VERSION = $VERSION;
 $VERSION = eval $VERSION;
 
@@ -329,8 +329,16 @@ become negative just became negative.  Maybe your compiler is broken?
 =head1 CAVEATS
 
 Notice that the core C<time()> maybe rounding rather than truncating.
-What this means is that the core C<time()> may be reporting the time as one second
-later than C<gettimeofday()> and C<Time::HiRes::time()>.
+What this means is that the core C<time()> may be reporting the time
+as one second later than C<gettimeofday()> and C<Time::HiRes::time()>.
+
+Adjusting the system clock (either manually or by services like ntp)
+may cause problems, especially for long running programs that assume
+a monotonously increasing time (note that all platforms do not adjust
+time as gracefully as UNIX ntp does).  For example in Win32 (and derived
+platforms like Cygwin and MinGW) the Time::HiRes::time() may temporarily
+drift off from the system clock (and the original time())  by up to 0.5
+seconds. Time::HiRes will notice this eventually and recalibrate.
 
 =head1 AUTHORS
 
diff --git a/ext/Time/HiRes/HiRes.xs b/ext/Time/HiRes/HiRes.xs
index fb516cd4d8..3505bf4a4e 100644
--- a/ext/Time/HiRes/HiRes.xs
+++ b/ext/Time/HiRes/HiRes.xs
@@ -181,11 +181,11 @@ START_MY_CXT
 #undef gettimeofday
 #define gettimeofday(tp, not_used) _gettimeofday(aTHX_ tp, not_used)
 
-/* If the performance counter delta drifts more than 2 seconds from the
- * system time then we recalibrate to system time.  This means we may
+/* If the performance counter delta drifts more than 0.5 seconds from the
+ * system time then we recalibrate to the system time.  This means we may
  * move *backwards* in time! */
 
-#define MAX_DIFF Const64(20000000)
+#define MAX_DIFF Const64(5000000)
 
 static int
 _gettimeofday(pTHX_ struct timeval *tp, void *not_used)