From: Michal Nazarewicz <mpn@google.com>
To: peff@peff.net, gitster@pobox.com
Cc: git@vger.kernel.org
Subject: [PATCHv4 4/6] Git.pm: allow pipes to be closed prior to calling command_close_bidi_pipe
Date: Tue, 12 Feb 2013 15:02:31 +0100 [thread overview]
Message-ID: <3bb6b7736eb4b0a958469be13d8c646faec1208a.1360677646.git.mina86@mina86.com> (raw)
In-Reply-To: <cover.1360677646.git.mina86@mina86.com>
In-Reply-To: <cover.1360677646.git.mina86@mina86.com>
From: Michal Nazarewicz <mina86@mina86.com>
The command_close_bidi_pipe() function will insist on closing both
input and output pipes returned by command_bidi_pipe(). With this
change it is possible to close one of the pipes in advance and
pass undef as an argument.
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
---
perl/Git.pm | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/perl/Git.pm b/perl/Git.pm
index 6bc9a3c..d6e6c9e 100644
--- a/perl/Git.pm
+++ b/perl/Git.pm
@@ -426,12 +426,25 @@ Note that you should not rely on whatever actually is in C<CTX>;
currently it is simply the command name but in future the context might
have more complicated structure.
+C<PIPE_IN> and C<PIPE_OUT> may be C<undef> if they have been closed prior to
+calling this function. This may be useful in a query-response type of
+commands where caller first writes a query and later reads response, eg:
+
+ my ($pid, $in, $out, $ctx) = $r->command_bidi_pipe('cat-file --batch-check');
+ print $out "000000000\n";
+ close $out;
+ while (<$in>) { ... }
+ $r->command_close_bidi_pipe($pid, $in, undef, $ctx);
+
+This idiom may prevent potential dead locks caused by data sent to the output
+pipe not being flushed and thus not reaching the executed command.
+
=cut
sub command_close_bidi_pipe {
local $?;
my ($self, $pid, $in, $out, $ctx) = _maybe_self(@_);
- _cmd_close($ctx, $in, $out);
+ _cmd_close($ctx, grep defined, $in, $out);
waitpid $pid, 0;
if ($? >> 8) {
throw Git::Error::Command($ctx, $? >>8);
--
1.8.1.3.572.g32bae1f
next prev parent reply other threads:[~2013-02-12 14:03 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-12 14:02 [PATCHv4 0/6] git-credential support in git-send-email Michal Nazarewicz
2013-02-12 14:02 ` [PATCHv4 1/6] Git.pm: allow command_close_bidi_pipe to be called as method Michal Nazarewicz
2013-02-12 14:02 ` [PATCHv4 2/6] Git.pm: fix example in command_close_bidi_pipe documentation Michal Nazarewicz
2013-02-12 14:02 ` [PATCHv4 3/6] Git.pm: refactor command_close_bidi_pipe to use _cmd_close Michal Nazarewicz
2013-02-12 18:55 ` Junio C Hamano
2013-02-12 20:48 ` Jeff King
2013-02-12 21:12 ` Michal Nazarewicz
2013-02-12 21:17 ` Junio C Hamano
2013-02-12 14:02 ` Michal Nazarewicz [this message]
2013-02-12 20:51 ` [PATCHv4 4/6] Git.pm: allow pipes to be closed prior to calling command_close_bidi_pipe Jeff King
2013-02-12 21:13 ` Michal Nazarewicz
2013-02-12 21:14 ` Junio C Hamano
2013-02-12 21:17 ` Jeff King
2013-02-12 22:50 ` Michal Nazarewicz
2013-02-12 14:02 ` [PATCHv4 5/6] Git.pm: add interface for git credential command Michal Nazarewicz
2013-02-27 14:18 ` Matthieu Moy
2013-02-12 14:02 ` [PATCHv4 6/6] git-send-email: use git credential to obtain password Michal Nazarewicz
2013-02-27 14:20 ` Matthieu Moy
2013-02-27 15:54 ` Junio C Hamano
2013-02-27 16:09 ` Michal Nazarewicz
2013-02-27 16:13 ` Matthieu Moy
2013-02-27 16:29 ` Junio C Hamano
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