[BUG?] setting ulimit in test suite broken for me

[BUG?] setting ulimit in test suite broken for me

[Stefan Beller]

Hi,

so I wanted to create a new test for large transactions, which should look like:

	run_with_limited_open_files () {
		(ulimit -n 64 && "$@")
	}

	test_lazy_prereq ULIMIT 'run_with_limited_open_files true'

	test_expect_success ULIMIT 'large transaction creating branches does not burst open file limit' '
	(
		echo $(ulimit -n)
		for i in $(seq 65)
		do
			echo "create refs/heads/$i HEAD"
		done >large_input &&
		git update-ref --stdin <large_input &&
		git rev-parse --verify -q refs/heads/65
	)
	'

Mind the "echo $(ulimit -n)" in there as a debugging output.
So if I run the test with "-d -v" to actually see the debugging output,
I see ulimit -n set to 32768 instead of the desired 64.

So I assumed I made a mistake and looked at other places with a similar
pattern such as in t7004-tag.sh. Inserting a debug statement (as attached,
so I don't need (to trust) -d and -v as parameters for the test) in there
also doesn't report the desired stack size of 128, but rather the system
default of 8192. Is that just my system or does anybody else also run into
such a problem?

Running ulimit -{n,s} manually in a shell (/bin/sh) as well as bash does
work as expected as it correctly reports with ulimit -a as well as breaking
the tests I try to write.

Thanks,
Stefan

Signed-off-by: Stefan Beller <sbeller@google.com>
---
 t/t7004-tag.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
index 35c805a..4f09cb4 100755
--- a/t/t7004-tag.sh
+++ b/t/t7004-tag.sh
@@ -1460,20 +1460,21 @@ test_expect_success 'invalid sort parameter in configuratoin' '
 '
 
 run_with_limited_stack () {
 	(ulimit -s 128 && "$@")
 }
 
 test_lazy_prereq ULIMIT 'run_with_limited_stack true'
 
 # we require ulimit, this excludes Windows
 test_expect_success ULIMIT '--contains works in a deep repo' '
+	echo $(ulimit -s) > ../ulimit_recorded
 	>expect &&
 	i=1 &&
 	while test $i -lt 8000
 	do
 		echo "commit refs/heads/master
 committer A U Thor <author@example.com> $((1000000000 + $i * 100)) +0200
 data <<EOF
 commit #$i
 EOF"
 		test $i = 1 && echo "from refs/heads/master^0"
-- 
2.2.1.62.g3f15098

Re: [BUG?] setting ulimit in test suite broken for me

[Jeff King]

On Wed, Jan 21, 2015 at 10:59:06AM -0800, Stefan Beller wrote:

> so I wanted to create a new test for large transactions, which should look like:
> 
> 	run_with_limited_open_files () {
> 		(ulimit -n 64 && "$@")
> 	}
> 
> 	test_lazy_prereq ULIMIT 'run_with_limited_open_files true'
> 
> 	test_expect_success ULIMIT 'large transaction creating branches does not burst open file limit' '
> 	(
> 		echo $(ulimit -n)
> 		for i in $(seq 65)
> 		do
> 			echo "create refs/heads/$i HEAD"
> 		done >large_input &&
> 		git update-ref --stdin <large_input &&
> 		git rev-parse --verify -q refs/heads/65
> 	)
> 	'
> 
> Mind the "echo $(ulimit -n)" in there as a debugging output.
> So if I run the test with "-d -v" to actually see the debugging output,
> I see ulimit -n set to 32768 instead of the desired 64.

You define run_with_limited_open_files, which starts a subshell, drops
the limit inside the subshell, and then spawns the child. But you never
call it in the test. Were you expecting that tests with the ULIMIT
prereq to automatically respect the limit? The prereq is just about
checking whether we can set the ulimit at all.

Try:

  run_with_limited_open_files ulimit -n

in your debugging statement (and of course use run_with... for the
actual git command you want to limit).

-Peff

Re: [BUG?] setting ulimit in test suite broken for me

[Stefan Beller]

On Wed, Jan 21, 2015 at 11:03 AM, Jeff King <peff@peff.net> wrote:
>
> in your debugging statement (and of course use run_with... for the
> actual git command you want to limit).
>

Thanks for that hint, its now part of the bugfix series.

Stefan