From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B366C433F5 for ; Thu, 26 May 2022 17:23:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345856AbiEZRXW (ORCPT ); Thu, 26 May 2022 13:23:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37726 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233201AbiEZRXV (ORCPT ); Thu, 26 May 2022 13:23:21 -0400 Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com [IPv6:2607:f8b0:4864:20::102d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 88783689A2 for ; Thu, 26 May 2022 10:23:20 -0700 (PDT) Received: by mail-pj1-x102d.google.com with SMTP id l7-20020a17090aaa8700b001dd1a5b9965so2243844pjq.2 for ; Thu, 26 May 2022 10:23:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=6pLu7A7zGrzrzRswxKQzBlFYKHR2FwPsBmaejkG/uf4=; b=b3EwDmdG4YsGTlJoaY+TuTmutubXDQfxcW3xc9u5XWzhc/htzGk3Ryc36vyt0wXtGU pPSu6FJBtZwxwaA+ih97Cn8R9TWTpkFaPqveoL3AjvC1RtDgGZ3LgOHfvw42yfJHbvhA TytV7bzSqDuFAuZKTi0/dcLqpgloBP/PI9wLI3LClAQZfb1RJL9g/ttVMLyiooh1CHMr pyf1+R9jqAd+zHg0epipYp1ZQtnpVZPT73E6idPY8ewVPqET2pyJGULSxuNT4ErAIqFe AdKN91Xah1etVloX291OdcZ7reg3J2t4iSfQ/vDosYCbanF4OQ0G6ALm5tGJ8rfjfCr3 vXcQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=6pLu7A7zGrzrzRswxKQzBlFYKHR2FwPsBmaejkG/uf4=; b=MPvpRGeCuNrtZgXZjWRnuw2OlbGJrNcvEFv01SW8xyDD4E0rRek2Q/UL9wYSFH+m8E Pr/s8ZF2e62czuy1dtAVhbyWt6qmKhjdYBZw9Y4ezIXt1UkAU00ix/8BJYWtHJo51vPq 0XdmfVJlurIXLo9Y8622mmroTpbCauQFAo3Z8pr7t9DDLfkWKYf/GLXwN6vclAt+RgJh U9GxCBs8yamcy3ftNZ2ID0pY3ugkKGhJ1ai++5G2sVAnUSmAZxSgF0l04crYaOdgLKHA LzAb2oEjg2Q3NN/Bbb1kbuNJmLDlwbeBH/9ACc2CXW8XokpcX2uYSMD++yfBOVpcOGxh TSVg== X-Gm-Message-State: AOAM531FlG0S+U3kx7onDou735mXuoslv83kOZeY+r+PnK6QHPol9SXU 76lf/njge8gdTbuIYS7cRttTxQ== X-Google-Smtp-Source: ABdhPJx8NhVPe8wS1yG1LEzWf7/fYC6/BT9mEQIR7SOk9A49XVx1uzaAD9HN/DjNrlvBvCxlF3Gg9Q== X-Received: by 2002:a17:90b:224a:b0:1e0:f91:3a3f with SMTP id hk10-20020a17090b224a00b001e00f913a3fmr3714187pjb.62.1653585799769; Thu, 26 May 2022 10:23:19 -0700 (PDT) Received: from google.com ([2620:15c:2ce:200:dcef:8d9b:c712:c6ca]) by smtp.gmail.com with ESMTPSA id jh9-20020a170903328900b0015e8d4eb244sm1815323plb.142.2022.05.26.10.23.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 26 May 2022 10:23:19 -0700 (PDT) Date: Thu, 26 May 2022 10:23:14 -0700 From: Emily Shaffer To: =?iso-8859-1?Q?=C6var_Arnfj=F6r=F0?= Bjarmason Cc: git@vger.kernel.org, Junio C Hamano , Anthony Sottile , Phillip Wood Subject: Re: [PATCH v2 8/8] hook API: fix v2.36.0 regression: hooks should be connected to a TTY Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Wed, May 18, 2022 at 10:05:24PM +0200, Ævar Arnfjörð Bjarmason wrote: > > Fix a regression reported[1] in f443246b9f2 (commit: convert > {pre-commit,prepare-commit-msg} hook to hook.h, 2021-12-22): Due to > using the run_process_parallel() API in the earlier 96e7225b310 (hook: > add 'run' subcommand, 2021-12-22) we'd capture the hook's stderr and > stdout, and thus lose the connection to the TTY in the case of > e.g. the "pre-commit" hook. > > As a preceding commit notes GNU parallel's similar --ungroup option > also has it emit output faster. While we're unlikely to have hooks > that emit truly massive amounts of output (or where the performance > thereof matters) it's still informative to measure the overhead. In a > similar "seq" test we're now ~30% faster: > > $ cat .git/hooks/seq-hook; git hyperfine -L rev origin/master,HEAD~0 -s 'make CFLAGS=-O3' './git hook run seq-hook' > #!/bin/sh > > seq 100000000 > Benchmark 1: ./git hook run seq-hook' in 'origin/master > Time (mean ± σ): 787.1 ms ± 13.6 ms [User: 701.6 ms, System: 534.4 ms] > Range (min … max): 773.2 ms … 806.3 ms 10 runs > > Benchmark 2: ./git hook run seq-hook' in 'HEAD~0 > Time (mean ± σ): 603.4 ms ± 1.6 ms [User: 573.1 ms, System: 30.3 ms] > Range (min … max): 601.0 ms … 606.2 ms 10 runs > > Summary > './git hook run seq-hook' in 'HEAD~0' ran > 1.30 ± 0.02 times faster than './git hook run seq-hook' in 'origin/master' > > In the preceding commit we removed the "stdout_to_stderr=1" assignment > as being redundant. This change brings it back as with ".ungroup=1" > the run_process_parallel() function doesn't provide them for us > implicitly. > > As an aside omitting the stdout_to_stderr=1 here would have all tests > pass, except those that test "git hook run" itself in > t1800-hook.sh. But our tests passing is the result of another test > blind spot, as was the case with the regression being fixed here. The > "stdout_to_stderr=1" for hooks is long-standing behavior, see > e.g. 1d9e8b56fe3 (Split back out update_hook handling in receive-pack, > 2007-03-10) and other follow-up commits (running "git log" with > "--reverse -p -Gstdout_to_stderr" is a good start). > > 1. https://lore.kernel.org/git/CA+dzEBn108QoMA28f0nC8K21XT+Afua0V2Qv8XkR8rAeqUCCZw@mail.gmail.com/ > > Reported-by: Anthony Sottile > Signed-off-by: Ævar Arnfjörð Bjarmason > --- > hook.c | 5 +++++ > t/t1800-hook.sh | 37 +++++++++++++++++++++++++++++++++++++ > 2 files changed, 42 insertions(+) > > diff --git a/hook.c b/hook.c > index dc498ef5c39..5f31b60384a 100644 > --- a/hook.c > +++ b/hook.c > @@ -54,6 +54,7 @@ static int pick_next_hook(struct child_process *cp, > return 0; > > strvec_pushv(&cp->env_array, hook_cb->options->env.v); > + cp->stdout_to_stderr = 1; /* because of .ungroup = 1 */ > cp->trace2_hook_name = hook_cb->hook_name; > cp->dir = hook_cb->options->dir; > > @@ -126,6 +127,7 @@ int run_hooks_opt(const char *hook_name, struct run_hooks_opt *options) > .tr2_label = hook_name, > > .jobs = jobs, > + .ungroup = jobs == 1, I mentioned it on patch 5, but I actually do not see a reason why we shouldn't do this logic in run_processes_parallel instead of just for the hooks. If someone can mention a reason we want to buffer child processes we're running in series I'm all ears, of course. > > .get_next_task = pick_next_hook, > .start_failure = notify_start_failure, > @@ -136,6 +138,9 @@ int run_hooks_opt(const char *hook_name, struct run_hooks_opt *options) > if (!options) > BUG("a struct run_hooks_opt must be provided to run_hooks"); > > + if (jobs != 1 || !run_opts.ungroup) > + BUG("TODO: think about & document order & interleaving of parallel hook output"); Doesn't this mean we're actually disallowing parallel hooks entirely? I don't think that's necessary or desired. I guess right now when the config isn't used, there's not really a way to provide parallel hooks, but I also think this will cause unnecessary conflicts for Google who is carrying config hooks downstream. I know that's not such a great reason. But it seems weird to be explicitly using the parallel processing framework, but then say, "oh, but we actually don't want to run in parallel, that's a BUG()". > + > if (options->invoked_hook) > *options->invoked_hook = 0; > > diff --git a/t/t1800-hook.sh b/t/t1800-hook.sh > index 1e4adc3d53e..f22754deccc 100755 > --- a/t/t1800-hook.sh > +++ b/t/t1800-hook.sh > @@ -4,6 +4,7 @@ test_description='git-hook command' > > TEST_PASSES_SANITIZE_LEAK=true > . ./test-lib.sh > +. "$TEST_DIRECTORY"/lib-terminal.sh > > test_expect_success 'git hook usage' ' > test_expect_code 129 git hook && > @@ -120,4 +121,40 @@ test_expect_success 'git -c core.hooksPath= hook run' ' > test_cmp expect actual > ' > > +test_hook_tty() { > + local fd="$1" && > + > + cat >expect && > + > + test_when_finished "rm -rf repo" && > + git init repo && > + > + test_hook -C repo pre-commit <<-EOF && > + { > + test -t 1 && echo >&$fd STDOUT TTY || echo >&$fd STDOUT NO TTY && > + test -t 2 && echo >&$fd STDERR TTY || echo >&$fd STDERR NO TTY > + } $fd>actual > + EOF > + > + test_commit -C repo A && > + test_commit -C repo B && > + git -C repo reset --soft HEAD^ && > + test_terminal git -C repo commit -m"B.new" && > + test_cmp expect repo/actual > +} > + > +test_expect_success TTY 'git hook run: stdout and stderr are connected to a TTY: STDOUT redirect' ' > + test_hook_tty 1 <<-\EOF > + STDOUT NO TTY > + STDERR TTY > + EOF > +' > + > +test_expect_success TTY 'git hook run: stdout and stderr are connected to a TTY: STDERR redirect' ' > + test_hook_tty 2 <<-\EOF > + STDOUT TTY > + STDERR NO TTY > + EOF > +' > + > test_done > -- > 2.36.1.952.g0ae626f6cd7 >