From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: michael.cadilhac@lrde.org (=?iso-8859-1?Q?Micha=EBl?= Cadilhac) Newsgroups: gmane.emacs.devel Subject: Re: delete-process bug Date: Mon, 29 May 2006 13:39:54 +0200 Organization: Epita/LRDE Message-ID: <87pshx2h6d.fsf@lrde.org> References: <87k69eyddj.fsf@lrde.org> <87fyj0r41g.fsf@lrde.org> <20060524112846.GA12046@agmartin.aq.upm.es> <87bqtmjrsh.fsf_-_@lrde.org> <87odxjakox.fsf@lrde.org> <8764jrlewm.fsf@lrde.org> <87pshyqgtd.fsf@lrde.org> <87fyiuq9t5.fsf@lrde.org> <877j45rj3w.fsf@lrde.org> <87odxhq1ah.fsf@lrde.org> NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0593365660==" X-Trace: sea.gmane.org 1148902783 2910 80.91.229.2 (29 May 2006 11:39:43 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Mon, 29 May 2006 11:39:43 +0000 (UTC) Cc: Agustin Martin , emacs-devel@gnu.org, "Kim F. Storm" Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon May 29 13:39:35 2006 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by ciao.gmane.org with esmtp (Exim 4.43) id 1Fkg5u-0003fW-4e for ged-emacs-devel@m.gmane.org; Mon, 29 May 2006 13:39:34 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Fkg5t-0002c8-HN for ged-emacs-devel@m.gmane.org; Mon, 29 May 2006 07:39:33 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Fkg5d-0002Zd-4R for emacs-devel@gnu.org; Mon, 29 May 2006 07:39:17 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Fkg5Z-0002VE-Gq for emacs-devel@gnu.org; Mon, 29 May 2006 07:39:16 -0400 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Fkg5Z-0002V5-Ed for emacs-devel@gnu.org; Mon, 29 May 2006 07:39:13 -0400 Original-Received: from [62.39.139.2] (helo=kualalumpur.lrde.epita.fr) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA:32) (Exim 4.52) id 1FkgB7-0006vR-M0 for emacs-devel@gnu.org; Mon, 29 May 2006 07:44:58 -0400 Original-Received: from mahaena.lrde.epita.fr ([192.168.101.66] helo=mahaena.lrde) by kualalumpur.lrde.epita.fr with esmtp (Exim 4.50) id 1Fkg5X-0002H2-JZ; Mon, 29 May 2006 13:39:11 +0200 Original-To: Stefan Monnier Face: iVBORw0KGgoAAAANSUhEUgAAADAAAAAwBAMAAAClLOS0AAAAElBMVEVWPh+Tai+5r5YKBAEU CQQzGAtiq7gjAAACR0lEQVQ4jW2UzW7lIAyFzVW8BzTZX5DmCZLuU2H2pMXv/ypzbK7aSh2kRCRf /HNsE0q7Sg+RQ7JFKaqtrRNAl5AIIKe6D5DBqgbmUAe5hBI1wIRFAHjeM0RKtZi7XVVEpb0BSNfA IddChChT5DildSLWOWhY5IEItMnncZgFcUAc/5jjwCMsDosRNdfKPDTFEdVBW8C+RebDb4N5Orio RhM1+11IJyx0ng2+LryFHBMPDQDYHrY6IfGuU3ouiXTQNE8LIJDKOWpNxERTFrggQwRPd7USUsTW fJ0XbR3bdj5KgBYy4SACpxDeUYEUAzLmtJ1iIrD2gczPq8Qomjhsh/RjGIgKIO8p7NITjwlx7WID nsnQe5NeuTvoBpi8LX6vLLOh5icjOHqBypgnuSp7M+RE1agbQKHQr5E2z1WObhYW4gMqeGQL7joM jCf2DxSk5ApADSYHfFF4igNfJZL1z0GKP0FN02s4XiDXr7V5P94W6I9v8MfBOQDmfwAaVYt+x8Da v4DJvX8BAdin3Knm5yMZYAO4ABDkDniZLLfi4P40gP1F0TPGZOu0CGwA1lcowxwlGy6A9705mD0V jHCxwVZT/hYdRJVUGZNlx6l7ScQBTluof6Wj6bsPYlvpwoTvXFD9gHPn2TZPF3ntI2ecxVrW5MrV XiCie5EeNa7BlWu/HNSkprDUva163PHxAv5jyGV7gVzyAghSKOTnat85UIYFICXbD2NV9rRiv0BS tKQsg6OHH4A15F1WW+UHKHHa32h6aPnAm3/pUcWp+WYnTQAAAABJRU5ErkJggg== In-Reply-To: (Stefan Monnier's message of "Sun, 28 May 2006 19:54:07 -0400") User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/22.0.50 (gnu/linux) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:55422 Archived-At: --===============0593365660== Content-Type: multipart/signed; boundary="==-=-="; micalg=pgp-sha1; protocol="application/pgp-signature" --==-=-= Content-Type: multipart/mixed; boundary="=-=-=" --=-=-= Stefan Monnier writes: >> In fact, there is already a configuration that would lead to the non >> deletion of the PID from the list: > >> - Call to delete_process, >> - Interrupted by a signal before inserting in deleted_processes_list , >> - Deletion from process_alist, > > How can this happen? Are you saying that a signal handler may delete the > process from process_alist? Which signal handler can do that? You're right, it's not its job. > I do think there's a leak but it goes like this: > > - catch the SIGCHLD signal > - start processing delete-process, which will add the PID to > deleted_pid_list even though the signal has already been caught so the pid > won't get a chance to be removed. > I guess we could check the process's status after adding it to > deleted_pid_list, to catch this case. I think it would be OK. Here's the new (new new) version of the patch. The kill_process part is not called if the process is already terminated. --=-=-= Content-Type: text/x-patch Content-Disposition: inline; filename=process.patch Content-Transfer-Encoding: quoted-printable Index: src/process.c =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D RCS file: /sources/emacs/emacs/src/process.c,v retrieving revision 1.481 diff -c -r1.481 process.c *** src/process.c 8 May 2006 05:19:42 -0000 1.481 =2D-- src/process.c 29 May 2006 11:36:31 -0000 *************** *** 778,783 **** =2D-- 778,793 ---- return proc; } =20=20 +=20 + #ifdef SIGCHLD + /* Fdelete_process promises to immediately forget about the process, but = in + reality, Emacs needs to remember those processes until they have been + treated by sigchld_handler; otherwise this handler would consider the + process as being synchronous and say that the synchronous process is + dead. */ + static Lisp_Object deleted_pid_list; + #endif +=20 DEFUN ("delete-process", Fdelete_process, Sdelete_process, 1, 1, 0, doc: /* Delete PROCESS: kill it and forget about it immediately. PROCESS may be a process, a buffer, the name of a process or buffer, or *************** *** 799,810 **** } else if (XINT (p->infd) >=3D 0) { ! Fkill_process (process, Qnil); ! /* Do this now, since remove_process will make sigchld_handler do n= othing. */ ! p->status ! =3D Fcons (Qsignal, Fcons (make_number (SIGKILL), Qnil)); ! XSETINT (p->tick, ++process_tick); ! status_notify (p); } remove_process (process); return Qnil; =2D-- 809,839 ---- } else if (XINT (p->infd) >=3D 0) { ! #ifdef SIGCHLD ! Lisp_Object symbol; !=20 ! /* No problem storing the pid here, as it is still in Vprocess_alis= t. */ ! deleted_pid_list =3D Fcons (make_fixnum_or_float (p->pid), ! /* GC treated elements set to nil. */ ! Fdelq (Qnil, deleted_pid_list)); ! /* If the process has already signaled, remove it from the list. */ ! if (p->raw_status_new) ! update_status (p); ! symbol =3D p->status; ! if (CONSP (p->status)) ! symbol =3D XCAR (p->status); ! if (EQ (symbol, Qsignal) || EQ (symbol, Qexit)) ! Fdelete (make_fixnum_or_float (p->pid), deleted_pid_list); ! else ! #endif ! { ! Fkill_process (process, Qnil); ! /* Do this now, since remove_process will make sigchld_handler do noth= ing. */ ! p->status ! =3D Fcons (Qsignal, Fcons (make_number (SIGKILL), Qnil)); ! XSETINT (p->tick, ++process_tick); ! status_notify (p); ! } } remove_process (process); return Qnil; *************** *** 6373,6378 **** =2D-- 6402,6418 ---- =20=20 /* Find the process that signaled us, and record its status. */ =20=20 + #ifdef SIGCHLD + /* The process can have been deleted by Fdelete_process. */ + tail =3D Fmember (make_fixnum_or_float (pid), deleted_pid_list); + if (!NILP (tail)) + { + Fsetcar (tail, Qnil); + goto sigchld_end_of_loop; + } + #endif +=20 + /* Otherwise, if it is asynchronous, it is in Vprocess_alist. */ p =3D 0; for (tail =3D Vprocess_alist; GC_CONSP (tail); tail =3D XCDR (tail)) { *************** *** 6424,6431 **** EMACS_SET_SECS_USECS (*input_available_clear_time, 0, 0); } =20=20 ! /* There was no asynchronous process found for that id. Check ! if we have a synchronous process. */ else { synch_process_alive =3D 0; =2D-- 6464,6471 ---- EMACS_SET_SECS_USECS (*input_available_clear_time, 0, 0); } =20=20 ! /* There was no asynchronous process found for that pid: we have ! a synchronous process. */ else { synch_process_alive =3D 0; *************** *** 6442,6447 **** =2D-- 6482,6491 ---- EMACS_SET_SECS_USECS (*input_available_clear_time, 0, 0); } =20=20 +=20 + sigchld_end_of_loop: + ; +=20 /* On some systems, we must return right away. If any more processes want to signal us, we will get another signal. *************** *** 6843,6848 **** =2D-- 6887,6895 ---- FD_SET (0, &input_wait_mask); =20=20 Vprocess_alist =3D Qnil; + #ifdef SIGCHLD + deleted_pid_list =3D Qnil; + #endif for (i =3D 0; i < MAXDESC; i++) { chan_process[i] =3D Qnil; *************** *** 6981,6986 **** =2D-- 7028,7036 ---- staticpro (&Qlast_nonmenu_event); =20=20 staticpro (&Vprocess_alist); + #ifdef SIGCHLD + staticpro (&deleted_pid_list); + #endif =20=20 DEFVAR_BOOL ("delete-exited-processes", &delete_exited_processes, doc: /* *Non-nil means delete processes immediately when they exi= t. --=-=-= Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable =2D-=20 | Micha=EBl `Micha' Cadilhac | Un certain Blaise Pascal = | | Epita/LRDE Promo 2007 | etc... etc... = | | http://www.lrde.org/~cadilh_m | -- Pr=E9vert (Les paris stupides) = | `-- - JID: micha@amessage.be --' - -= -' --=-=-=-- --==-=-= Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) iD8DBQFEet2KZYNf4qobZ7kRAsIQAJ9PxBSrUckJPTq8WaMaFzGXgkHNjgCgurmY onKEbNiZQjE8xk1lR8KMerU= =N/5l -----END PGP SIGNATURE----- --==-=-=-- --===============0593365660== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Emacs-devel mailing list Emacs-devel@gnu.org http://lists.gnu.org/mailman/listinfo/emacs-devel --===============0593365660==--