Merge branch 'gawk-4.1-stable'

4 files changed, 38 insertions, 14 deletions

diff --git a/test/ChangeLog b/test/ChangeLog
index 52eade27..90e34c8b 100644
--- a/test/ChangeLog
+++ b/test/ChangeLog
@@ -1,3 +1,13 @@
+2014-01-16         Andrew J. Schorr     <aschorr@telemetry-investments.com>
+
+	* Makefile.am (strftime): Remove comment about the race condition, since
+	this should be fixed.  And gawk now calls date inside the script.
+	* strftime.awk: Based on an idea from Pat Ranking, fix the race
+	condition by looping repeatedly over strftime/date/strftime until
+	the before and after strftime results match.  That should fix
+	the race condition where the seconds field might increment between
+	invocations.
+
 2014-01-14         Arnold D. Robbins     <arnold@skeeve.com>
 
 	* Makefile.am (split_after_fpat): New test.
diff --git a/test/Makefile.am b/test/Makefile.am
index 56547d11..82492c41 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -1254,12 +1254,10 @@ nonl::
 	@-$(CMP) "$(srcdir)"/$@.ok _$@ && rm -f _$@
 
 strftime::
-	@echo This test could fail on slow machines or on a minute boundary,
-	@echo so if it does, double check the actual results:
 	@echo $@
 	@GAWKLOCALE=C; export GAWKLOCALE; \
 	TZ=GMT0; export TZ; \
-	(LC_ALL=C date) | $(AWK) -v OUTPUT=_$@ -f "$(srcdir)"/strftime.awk
+	$(AWK) -v OUTPUT=_$@ -f "$(srcdir)"/strftime.awk
 	@-$(CMP) strftime.ok _$@ && rm -f _$@ strftime.ok || exit 0
 
 litoct::
diff --git a/test/Makefile.in b/test/Makefile.in
index 216dde28..3b088b7f 100644
--- a/test/Makefile.in
+++ b/test/Makefile.in
@@ -1678,12 +1678,10 @@ nonl::
 	@-$(CMP) "$(srcdir)"/$@.ok _$@ && rm -f _$@
 
 strftime::
-	@echo This test could fail on slow machines or on a minute boundary,
-	@echo so if it does, double check the actual results:
 	@echo $@
 	@GAWKLOCALE=C; export GAWKLOCALE; \
 	TZ=GMT0; export TZ; \
-	(LC_ALL=C date) | $(AWK) -v OUTPUT=_$@ -f "$(srcdir)"/strftime.awk
+	$(AWK) -v OUTPUT=_$@ -f "$(srcdir)"/strftime.awk
 	@-$(CMP) strftime.ok _$@ && rm -f _$@ strftime.ok || exit 0
 
 litoct::
diff --git a/test/strftime.awk b/test/strftime.awk
index 775cd4e5..a52957f0 100644
--- a/test/strftime.awk
+++ b/test/strftime.awk
@@ -2,18 +2,36 @@
 #
 # input is the output of `date', see Makefile.in
 #
-# The mucking about with $0 and $N is to avoid problems
+# The mucking about with $0 and $NF is to avoid problems
 # on cygwin, where the timezone field is empty and there
 # are two consecutive blanks.
 
-# Additional mucking about to lop off the seconds field;
-# helps decrease chance of difference due to a second boundary
+BEGIN {
+	maxtries = 10
+	datecmd = "date"
+	fmt = "%a %b %d %H:%M:%S %Z %Y"
 
-{
-	$3 = sprintf("%02d", $3 + 0)
-	$4 = substr($4, 1, 5)
-	print > "strftime.ok"
-	$0 = strftime("%a %b %d %H:%M %Z %Y")
+	# loop until before equals after, thereby protecting
+	# against a race condition where the seconds field might have
+	# incremented between running date and strftime
+	i = 0
+	while (1) {
+		if (++i > maxtries) {
+			printf "Warning: this system is so slow that after %d attempts, we could never get two sequential invocations of strftime to give the same result!\n", maxtries > "/dev/stderr"
+			break
+		}
+		before = strftime(fmt)
+		datecmd | getline sd
+		after = strftime(fmt)
+		close(datecmd)
+		if (before == after) {
+			if (i > 1)
+				printf "Notice: it took %d loops to get the before and after strftime values to match\n", i > "/dev/stderr"
+			break
+		}
+	}
+	print sd > "strftime.ok"
+	$0 = after
 	$NF = $NF
 	print > OUTPUT
 }