From 11dc0016bb72372bbd46b964fb57f4d10448225a Mon Sep 17 00:00:00 2001
From: Pádraig Brady <P@draigBrady.com>
Date: Tue, 22 Dec 2009 07:36:12 +0000
Subject: wc: line-buffer the printed counts

* src/wc.c (main): Set stdout to line buffered mode
to ensure parallel running instances don't intersperse
their output.  This adds 6.5% to the run time in the worst case
of many zero length files, but has neglible impact for
standard sized files.
* tests/misc/wc-parallel: New test for atomic output.
* tests/Makefile.am: Reference it.
* NEWS: Mention the fix
This is similar to commit 710fe413, 20-10-2009,
"md5sum, sha*sum, sum: line-buffer the printed checksums"
---
 tests/Makefile.am      |  1 +
 tests/misc/wc-parallel | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)
 create mode 100755 tests/misc/wc-parallel

(limited to 'tests')

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 5e44202ba..93d4275cd 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -157,6 +157,7 @@ TESTS =						\
   misc/wc					\
   misc/wc-files0-from				\
   misc/wc-files0				\
+  misc/wc-parallel				\
   misc/cat-proc					\
   misc/cat-buf					\
   misc/base64					\
diff --git a/tests/misc/wc-parallel b/tests/misc/wc-parallel
new file mode 100755
index 000000000..7c74c5518
--- /dev/null
+++ b/tests/misc/wc-parallel
@@ -0,0 +1,37 @@
+#!/bin/sh
+# Ensure that wc prints counts atomically
+# so that concurrent processes don't intersperse their output
+
+# Copyright (C) 2009 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+. $srcdir/test-lib.sh
+
+if test "$VERBOSE" = yes; then
+  set -x
+  md5sum --version
+fi
+
+
+(mkdir tmp && cd tmp && seq 2000 | xargs touch)
+
+# This will output at least 16KiB per process
+# and start 3 processes, with 2 running concurrently,
+# which triggers often on Fedora 11 at least.
+(find tmp tmp tmp -type f | xargs -n2000 -P2 wc) |
+sed -n '/0 0 0 /!p' |
+grep . > /dev/null && fail=1
+
+Exit $fail
-- 
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