GNU bug report logs - #5723
23.1.94; make-network-process and emacs hangs

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Package: emacs;

Reported by: Leo <sdl.web <at> gmail.com>

Date: Mon, 15 Mar 2010 16:02:01 UTC

Severity: normal

Done: YAMAMOTO Mitsuharu <mituharu <at> math.s.chiba-u.ac.jp>

Bug is archived. No further changes may be made.

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Message #53 received at 5723 <at> debbugs.gnu.org (full text, mbox):

From: YAMAMOTO Mitsuharu <mituharu <at> math.s.chiba-u.ac.jp>
To: Helmut Eller <eller.helmut <at> gmail.com>
Cc: 5723 <at> debbugs.gnu.org
Subject: Re: bug#5723: 23.1.94; make-network-process and emacs hangs
Date: Fri, 19 Mar 2010 10:47:05 +0900

>>>>> On Thu, 18 Mar 2010 18:06:20 +0900, YAMAMOTO Mitsuharu <mituharu <at> math.s.chiba-u.ac.jp> said:

>>> If your case blocks at `connect', then it can't be quit with C-g
>>> regardless of SYNC_INPUT on those ports/systems, because atimer is
>>> turned off during the `connect' call.

>> Why is the timer turned off around connect?  Handling SIGALARM
>> during connect doesn't seem much different from handling SIGIO.

> I think your argument makes sense.

The current code closes the socket and call `connect' again if
(blocking) `connect' is interrupted by a signal.

2004-11-09  Kim F. Storm  <storm <at> cua.dk>

	* process.c (Fmake_network_process): Remove kludge for interrupted
	connects on BSD.  If connect is interrupted, just close socket and
	start over rather than sleeping and retry with same socket.

(http://cvs.savannah.gnu.org/viewvc/emacs/src/process.c?root=emacs&r1=1.443&r2=1.444)

UNIX Network Programming (Richard Stevens et al.) says "What we must
do in this scenario is call /select/" (Section 16,5, Volume 1 third
edition).

Also, POSIX says:

  If connect() is interrupted by a signal that is caught while blocked
  waiting to establish a connection, connect() shall fail and set
  errno to [EINTR], but the connection request shall not be aborted,
  and the connection shall be established asynchronously.

  ...

  When the connection has been established asynchronously, select()
  and poll() shall indicate that the file descriptor for the socket is
  ready for writing.

(http://www.opengroup.org/onlinepubs/000095399/functions/connect.html)

Perhaps we should try this, not just removing `turn_on_atimers' calls.

				     YAMAMOTO Mitsuharu
				mituharu <at> math.s.chiba-u.ac.jp
This bug report was last modified 15 years and 67 days ago.

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