threads / patch / 48998

patcht1404: increase core.packedRefsTimeout to avoid occasional test failure

Subject: [PATCH] t1404: increase core.packedRefsTimeout to avoid occasional test failure

## tl;dr

3 messages between Jul 31, 2018 and Aug 1, 2018. Diffs are folded; open one to read it.

replies: 2people: 2as markdown or json

SZEDER Gábor· Jul 31, 2018, 23:32 UTC · lore

The test 'no bogus intermediate values during delete' in 't1404-update-ref-errors.sh', added in 6a2a7736d8 (t1404: demonstrate two problems with reference transactions, 2017-09-08), tries to catch undesirable side effects of deleting a ref, both loose and packed, in a transaction. To do so it is holding the packed refs file locked when it starts 'git update-ref -d' in the background with a 3secs 'core.packedRefsTimeout' value. After performing a few checks it is then supposed to unlock the packed refs file before the background 'git update-ref's attempt to acquire the lock times out.

While 3secs timeout seems plenty, and indeed is sufficient in most cases, on rare occasions it's just not quite enough: I saw this test fail in Travis CI build jobs two, maybe three times because 'git update-ref' timed out.

Increase that timeout by an order of magnitude to 30s to make such an occasional failure even more improbable. This won't make the test run any longer under normal circumstances, because 'git update-ref' will acquire the lock and resume execution as soon as it can. And if it turns out that even this increased timeout is still not enough, then there are most likely bigger problems, e.g. the Travis CI build job will exceed its time limit anyway, or the lockfile module is broken.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
---
 t/t1404-update-ref-errors.sh | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
Show changes to t/t1404-update-ref-errors.sh +3 −3
diff --git a/t/t1404-update-ref-errors.sh b/t/t1404-update-ref-errors.sh
index 3a887b5113..372f0b1fbb 100755
--- a/t/t1404-update-ref-errors.sh
+++ b/t/t1404-update-ref-errors.sh
@@ -559,9 +559,9 @@ test_expect_success 'no bogus intermediate values during delete' '
 	{
 		# Note: the following command is intentionally run in the
 		# background. We increase the timeout so that `update-ref`
-		# attempts to acquire the `packed-refs` lock for longer than
-		# it takes for us to do the check then delete it:
-		git -c core.packedrefstimeout=3000 update-ref -d $prefix/foo &
+		# attempts to acquire the `packed-refs` lock for much longer
+		# than it takes for us to do the check then delete it:
+		git -c core.packedrefstimeout=30000 update-ref -d $prefix/foo &
 	} &&
 	pid2=$! &&
 	# Give update-ref plenty of time to get to the point where it tries

-- 
2.18.0.408.g42635c01bc
Jonathan Nieder· Jul 31, 2018, 23:39 UTC · re: SZEDER Gábor · lore

Re: [PATCH] t1404: increase core.packedRefsTimeout to avoid occasional test failure

Hi,
SZEDER Gábor wrote:
> While 3secs timeout seems plenty, and indeed is sufficient in most
> cases, on rare occasions it's just not quite enough: I saw this test
> fail in Travis CI build jobs two, maybe three times because 'git
> update-ref' timed out.

I suspect these tests will fail with valgrind (just because valgrind makes things super slow). Would it be safe to use timeout=-1?

Thanks, Jonathan

SZEDER Gábor· Aug 1, 2018, 01:37 UTC · re: Jonathan Nieder · lore

Re: [PATCH] t1404: increase core.packedRefsTimeout to avoid occasional test failure

On Wed, Aug 1, 2018 at 1:39 AM Jonathan Nieder <jrnieder@gmail.com> wrote:
Show 9 quoted lines
> SZEDER Gábor wrote:
>
> > While 3secs timeout seems plenty, and indeed is sufficient in most
> > cases, on rare occasions it's just not quite enough: I saw this test
> > fail in Travis CI build jobs two, maybe three times because 'git
> > update-ref' timed out.
>
> I suspect these tests will fail with valgrind (just because valgrind
> makes things super slow).  Would it be safe to use timeout=-1?

I don't know. Travis CI has a time limit of about 45mins for the whole build job (including installing dependencies and compilation), and any sensible automated build system must have a similar time limit, so it would be fine to wait indefinitely in such an environment, though in case of a timeout we'd lose failure reports of failed tests, if there are any.

OTOH, my (and I guess most devs') test runs don't have such a time limit, so I'm reluctant to change it to wait indefinitely. But then again, waiting indefinitely for a lock file is not all that different from messing up something and creating an endless loop or a deadlock...

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