From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jeff King <peff@peff.net>
Subject: Re: t5800-*.sh: Intermittent test failures
Date: Thu, 8 Sep 2011 14:20:55 -0400
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Cc: Junio C Hamano <gitster@pobox.com>,
	Sverre Rabbelier <srabbelier@gmail.com>,
	GIT Mailing-list <git@vger.kernel.org>,
	Jonathan Nieder <jrnieder@gmail.com>
To: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
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On Thu, Sep 08, 2011 at 06:42:11PM +0100, Ramsay Jones wrote:

> When I run the tests with "make test >test-out", I see a failure rate of about
> 1 in 10. If I then set the debug environment variables (GIT_TRANSPORT_HELPER_DEBUG,
> GIT_TRANSLOOP_DEBUG and GIT_DEBUG_TESTGIT) and run the test script directly (-v),
> then the failure rate goes up to about 1 in 3.

Hmm. I can't reproduce a failure here, but I do get some weirdness. My
recipe is:

-- >8 --
cat >foo.sh <<\EOF
#!/bin/sh

exec >$1.out 2>&1

n=0
while test $n -lt 100; do
	n=$(($n+1))
	GIT_TRANSPORT_HELPER_DEBUG=1 \
	GIT_TRANSLOOP_DEBUG=1 \
	GIT_DEBUG_TESTGIT=1 \
	./t5800-remote-helpers.sh --root=/run/shm/git-tests-$1 -v || {
		echo FAIL $n
		exit 1
	}
	echo OK $n
done
EOF

# try to keep an 8-core machine busy
for i in `seq 1 16`; do
  sh foo.sh $i &
done
-- 8< --

I never see a test failure, but a few of the 16 end up hanging. The
process tree for the hanged tests look like:

  t5800-remote-helper
    git push
      git-remote-testgit
        git fast-import
          git-fast-import

All of them are blocked on wait(), except for the final fast-import,
which is blocked trying to read() from stdin.

-Peff