Subject: Re: [PATCH v9 00/19] index-helper/watchman

From: Dennis Kaarsemaker <[email-masked]>
Date: Tue, 10 May 2016 19:28:24 +0200

On ma, 2016-05-09 at 15:32 -0700, Junio C Hamano wrote:
> Junio C Hamano <[email-masked]> writes:
> 
> > 
> > David Turner <[email-masked]> writes:
> > 
> > > 
> > > On Mon, 2016-05-09 at 14:40 -0700, Junio C Hamano wrote:
> > > > 
> > > > Hmmm, I seem to be getting
> > > > 
> > > >     $ cat t/trash*7900*/err
> > > >     fatal: Already running
> > > > 
> > > > after running t7900 and it fails at #5, after applying
> > > > "index-helper: optionally automatically run"
> The symptom looks pretty similar to $gmane/293461 reported earlier.
> Here is how "t7900-index-helper.sh -i -v -x -d" ends.
> 
> 
> expecting success:
>         test_when_finished "git index-helper --kill" &&
>         rm -f .git/index-helper.sock &&
>         git status &&
>         test_path_is_missing .git/index-helper.sock &&
>         test_config indexhelper.autorun true &&
>         git status &&
>         test -S .git/index-helper.sock &&
>         git status 2>err &&
>         test -S .git/index-helper.sock &&
>         test_must_be_empty err &&
>         git index-helper --kill &&
>         test_config indexhelper.autorun false &&
>         git status &&
>         test_path_is_missing .git/index-helper.sock
> 
> + test_when_finished git index-helper --kill
> + test 0 = 0
> + test_cleanup={ git index-helper --kill
>                 } && (exit "$eval_ret"); eval_ret=$?; :
> + rm -f .git/index-helper.sock
> + git status
> On branch master
> Untracked files:
>   (use "git add <file>..." to include in what will be committed)
> 
>         err
> 
> nothing added to commit but untracked files present (use "git add" to
> track)
> + test_path_is_missing .git/index-helper.sock
> + test -e .git/index-helper.sock
> + test_config indexhelper.autorun true
> + config_dir=
> + test indexhelper.autorun = -C
> + test_when_finished test_unconfig  'indexhelper.autorun'
> + test 0 = 0
> + test_cleanup={ test_unconfig  'indexhelper.autorun'
>                 } && (exit "$eval_ret"); eval_ret=$?; { git index-
> helper --kill
>                 } && (exit "$eval_ret"); eval_ret=$?; :
> + git config indexhelper.autorun true
> + git status
> error: last command exited with $?=141
> not ok 5 - index-helper autorun works
> #
> #               test_when_finished "git index-helper --kill" &&
> #               rm -f .git/index-helper.sock &&
> #               git status &&
> #               test_path_is_missing .git/index-helper.sock &&
> #               test_config indexhelper.autorun true &&
> #               git status &&
> #               test -S .git/index-helper.sock &&
> #               git status 2>err &&
> #               test -S .git/index-helper.sock &&
> #               test_must_be_empty err &&
> #               git index-helper --kill &&
> #               test_config indexhelper.autorun false &&
> #               git status &&
> #               test_path_is_missing .git/index-helper.sock
> #

Here are the relevant bits of a strace, pid 22200 is the second git
status, 222197 is the index helper. 22122 is the test script

22200 socket(PF_LOCAL, SOCK_STREAM, 0)  = 7
22200 connect(7, {sa_family=AF_LOCAL, sun_path=".git/index-helper.sock"}, 110 <unfinished ...>
22197 <... poll resumed> )              = 1
22197 accept(7, 0, NULL)                = 8
22197 fcntl(8, F_GETFL)                 = 0x2 (flags O_RDWR)
22197 fcntl(8, F_SETFL, O_RDWR)         = 0
22197 read(8,  <unfinished ...>
22200 <... connect resumed> )           = 0
22200 rt_sigaction(SIGPIPE, {SIG_IGN, [PIPE], SA_RESTORER|SA_RESTART, 0x7fcc463fdd40}, {SIG_DFL, [PIPE], SA_RESTORER|SA_RESTART, 0x7fcc463fdd40}, 8) = 0
22200 write(7, "000fpoke 22200 ", 15 <unfinished ...>
22197 <... read resumed> 0x7ffc4e4b9b20, 4) = 4
22197 read(8, 0x7ffc4e4b9c70, 11)       = 11
22197 write(8, 0x18b08b0, 6)            = 6
22197 close(8)                          = 0
22197 poll([?] 0x7ffc4e4b9b80, 1, 600000 <unfinished ...>
22200 <... write resumed> )             = 15
22200 write(7, "0000", 4)               = -1 EPIPE (Broken pipe)
22200 --- SIGPIPE {si_signo=SIGPIPE, si_code=SI_USER, si_pid=22200, si_uid=1000} ---
22200 rt_sigaction(SIGPIPE, {SIG_DFL, [PIPE], SA_RESTORER|SA_RESTART, 0x7fcc463fdd40}, {SIG_IGN, [PIPE], SA_RESTORER|SA_RESTART, 0x7fcc463fdd40}, 8) = 0
22200 tgkill(22200, 22200, SIGPIPE)     = 0   
22200 --- SIGPIPE {si_signo=SIGPIPE, si_code=SI_TKILL, si_pid=22200, si_uid=1000} ---
22200 +++ killed by SIGPIPE +++
22122 <... wait4 resumed> [{WIFSIGNALED(s) && WTERMSIG(s) == SIGPIPE}], 0, NULL) = 22200 
22122 --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_KILLED, si_pid=22200, si_status=SIGPIPE, si_utime=0, si_stime=0} ---

Looks like the index helper closes the socket, but git status still
wants to write to it. The index-helper also doesn't seem to read all
data from the socket.

-- 
Dennis Kaarsemaker
www.kaarsemaker.net