1 files changed, 36 insertions, 0 deletions
diff --git a/tests/misc/wc-parallel.sh b/tests/misc/wc-parallel.sh
new file mode 100755
index 0000000..4da4d94
--- /dev/null
+++ b/tests/misc/wc-parallel.sh
@@ -0,0 +1,36 @@
+#!/bin/sh
+# Ensure that wc prints counts atomically
+# so that concurrent processes don't intersperse their output
+
+# Copyright (C) 2009-2020 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 <https://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
+print_ver_ wc
+
+xargs -P2 </dev/null >/dev/null 2>&1 \
+  || skip_ 'xargs -P is required'
+
+(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 2>err) |
+sed -n '/0 0 0 /!p' |
+grep . > /dev/null && fail=1
+compare /dev/null err || fail=1
+
+Exit $fail