Re: [PATCH 2/2] daemon: graceful shutdown of client connection
- From
Johannes Schindelin <johannes.schindelin@gmx.de>
- Date
- Apr 18, 2018, 21:48 UTC
- Message-ID
- <nycvar.QRO.7.76.6.1804182316420.4241@ZVAVAG-6OXH6DA.rhebcr.pbec.zvpebfbsg.pbz>
- In-Reply-To
- <20180415202122.GA4657@infogroep.be>
Hi Kim,
On Sun, 15 Apr 2018, Kim Gybels wrote:
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> On (13/04/18 15:03), Johannes Schindelin wrote: > > I wonder whether you found a reliable way to trigger this? It would be > > nice to have a regression test for this. > > On my system, it reproduced reliably using Oleg's example [1], below is > my bash version of it.
Okay.
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> Script to generate repository with some history: > > $ cat example.sh > #!/bin/bash > > git init example > cd example > > git --help > foo.txt > > for i in $(seq 1 12); do > cat foo.txt foo.txt > bar.txt > mv bar.txt foo.txt > git add foo.txt > git commit -m v$i > done
Okay, so this sets up a minimal repository with a moderate size, inflating foo.txt from the initial Git help text by factor 2**12 = 4096. The help text is around 2kB, so we end up with an ~8MB large file in the end that grew exponentially.
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> $ ./example.sh > Initialized empty Git repository in C:/git/bug/example/.git/ > [master (root-commit) 2e44b4a] v1 > 1 file changed, 84 insertions(+) > create mode 100644 foo.txt > [master 9791332] v2 > 1 file changed, 84 insertions(+) > [master 524e672] v3 > 1 file changed, 168 insertions(+) > [master afec6ef] v4 > 1 file changed, 336 insertions(+) > [master 1bcd9cc] v5 > 1 file changed, 672 insertions(+) > [master 2f38a8e] v6 > 1 file changed, 1344 insertions(+) > [master 33382fe] v7 > 1 file changed, 2688 insertions(+) > [master 6c2cbd6] v8 > 1 file changed, 5376 insertions(+) > [master 8d0770f] v9 > 1 file changed, 10752 insertions(+) > [master 517d650] v10 > 1 file changed, 21504 insertions(+) > [master 9e12406] v11 > 1 file changed, 43008 insertions(+) > [master 4c4f600] v12 > 1 file changed, 86016 insertions(+) > > Server side: > > $ git daemon --verbose --reuseaddr --base-path=$(pwd) --export-all > [4760] Ready to rumble > [696] Connection from 127.0.0.1:2054 > [696] unable to set SO_KEEPALIVE on socket: No such file or directory > [696] Extended attribute "host": 127.0.0.1 > [696] Request upload-pack for '/example'
I guess apart from the generated repo size (which would make this an expensive test in and of itself), the fact that we have to run the daemon (and that lib-git-daemon.sh requires the PIPE prerequisite which we disabled on Windows) makes it hard to turn this into a regular regression test in t/.
Although we *could* of course introduce a test that does not use lib-git-daemon.sh and is hidden behind the EXPENSIVE prerequisite or some such.
BTW I just tested this, and it indeed fixes the problem, so I am eager to ship it to the Git for Windows users. Let's see whether we can convince Junio that your quite small and easy-to-review patches are not too much of a maintenance burden, and the fact that they fix a long-standing bug should help.
BTW I had to apply this to build with DEVELOPER=1:
diff --git a/daemon.c b/daemon.c index 97fadd62d10..1cc901e9739 100644 --- a/daemon.c +++ b/daemon.c @@ -1162,13 +1162,13 @@ static int service_loop(struct socketlist *socklist) signal(SIGCHLD, child_handler); for (;;) { - int i; + int i, ret; check_dead_children(); #ifdef NO_POLL poll_timeout = live_children ? 100 : -1; #endif - int ret = poll(pfd, socklist->nr, poll_timeout); + ret = poll(pfd, socklist->nr, poll_timeout); if (ret == 0) { continue; } else if (ret < 0) { Would you mind squashing that in? Thanks, Dscho