Re: [PATCH 2/2] t9700: ensure cat-file info isn't buffered by default

From: Phillip Wood <phillip.wood123@gmail.com>
Date: Jun 19, 2024, 09:08 UTC
Message-ID: <6e80eea5-b6ce-4218-8c43-dde2b5a698f5@gmail.com>
In-Reply-To: <20240617104326.3522535-3-e@80x24.org>

Hi Eric

On 17/06/2024 11:43, Eric Wong wrote:

> +# ensure --batch-check is unbuffered by default
> +my ($pid, $in, $out, $ctx) = $r->command_bidi_pipe(qw(cat-file --batch-check));
> +print $out $file1hash, "\n" or die $!;

It's been a while since I did any perl scripting and I'm not clear whether $out is buffered or not and if it is whether it is guaranteed to be flushed when we print "\n". It might be worth adding a explicit flush so it is clear that any deadlocks come from cat-file and not our test code.

> +my $info = <$in>;

Is there an easy way to add a timeout to this read so that the failure mode isn't "the test hangs without printing anything"? I'm not sure that failure mode is easy to diagnose from our CI output as it is hard to tell which test caused the CI to timeout and it takes ages for the CI to time out.

Best Wishes

Phillip

Show 14 quoted lines

> +is $info, "$file1hash blob 15\n", 'command_bidi_pipe w/ --batch-check';
> +$r->command_close_bidi_pipe($pid, $in, $out, $ctx);
> +
> +# ditto with `info' with --batch-command
> +($pid, $in, $out, $ctx) = $r->command_bidi_pipe(qw(cat-file --batch-command));
> +print $out 'info ', $file1hash, "\n" or die $!;
> +$info = <$in>;
> +is $info, "$file1hash blob 15\n", 'command_bidi_pipe w/ --batch-command=info';
> +$r->command_close_bidi_pipe($pid, $in, $out, $ctx);
> +
>   printf "1..%d\n", Test::More->builder->current_test;
>   
>   my $is_passing = eval { Test::More->is_passing };
>