From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Ihor Radchenko Newsgroups: gmane.emacs.devel Subject: Re: Concurrency via isolated process/thread Date: Mon, 10 Jul 2023 12:28:17 +0000 Message-ID: <878rbo6jdq.fsf@localhost> References: <871qhnr4ty.fsf@localhost> <87zg48apwr.fsf@localhost> <83edljg8ub.fsf@gnu.org> <87o7knbxr7.fsf@localhost> <838rbrg4mg.fsf@gnu.org> <87ilavbvdr.fsf@localhost> <834jmffvhy.fsf@gnu.org> <878rbrbmwr.fsf@localhost> <83fs5zecpo.fsf@gnu.org> <87351zbi72.fsf@localhost> <83351yevde.fsf@gnu.org> <87cz12ad2w.fsf@localhost> <83a5w6cwdr.fsf@gnu.org> <87pm518m0g.fsf@localhost> <83o7kl9tyj.fsf@gnu.org> <874jmd89us.fsf@localhost> <83cz119lxu.fsf@gnu.org> <87v8et6q5m.fsf@localhost> <838rbp9h6c.fsf@gnu.org> <87edlg6m2l.fsf@localhost> <87o7kkc6bl.fsf@yahoo.com> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="20477"; mail-complaints-to="usenet@ciao.gmane.io" Cc: Eli Zaretskii , monnier@iro.umontreal.ca, emacs-devel@gnu.org To: Po Lu Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Mon Jul 10 14:29:29 2023 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qIq17-00052f-Aj for ged-emacs-devel@m.gmane-mx.org; Mon, 10 Jul 2023 14:29:25 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qIq08-0008IN-Ri; Mon, 10 Jul 2023 08:28:25 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qIq06-0008HO-CC for emacs-devel@gnu.org; Mon, 10 Jul 2023 08:28:22 -0400 Original-Received: from mout02.posteo.de ([185.67.36.66]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qIpzz-0000ja-A6 for emacs-devel@gnu.org; Mon, 10 Jul 2023 08:28:20 -0400 Original-Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id 56D66240104 for ; Mon, 10 Jul 2023 14:28:10 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.net; s=2017; t=1688992090; bh=tiI3RW7hbFTKVtv6WUOU+tdEZuek5O0DzG2cj65fNlA=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:From; b=hLJm9eX4vjpNi9ic/EKDb0mXkgs3/iekXj0Bv7DAd7W9ejL6/IP5kGlKxvqC+ccgD F97neQEA2BDVFC7pos7O6fYZLfbAr/S3td6NjfYqGsu2x5y3FmZ0pXrEjtTB3UukNE S+qdI7HOqBKgoPhey8a6b7VclkFXTrZouRk5xXG8x91ht1iW1VdiQtlxl2O5aZC4WE RqL+BVN7GdFG7e0qLWK+eWpOGV/m1HEnAqS5XEoagR+C4IglXe871Vh5+JoTuP9W0w 6B9rnqmTNwkOBXbAjiZyNwfRfdw9Ap2Uiwq3vDx5gERQydqqxfgY26ezrFTiWPmeqn a9r0QKkB9uJ2Q== Original-Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4R03F517jBz9rxT; Mon, 10 Jul 2023 14:28:08 +0200 (CEST) In-Reply-To: <87o7kkc6bl.fsf@yahoo.com> Received-SPF: pass client-ip=185.67.36.66; envelope-from=yantar92@posteo.net; helo=mout02.posteo.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:307715 Archived-At: Po Lu writes: > Ihor Radchenko writes: > >> AFAIU, we can then raise a flag that GC is necessary, so that other >> threads will stop next time they reach maybe_gc, until GC is complete. > > What if even one of those other threads never calls maybe_gc? This can > easily happen if they are blocked by a long running operation (domain > name resolution comes to mind) and will result in all threads waiting > for it to complete, defeating the purpose of having threads in the first > place. Good point. Maybe something similar to how thread-yield is triggered by `accept-process-output' - add extra maybe_gc() to process code as necessary. > TRT on GNU and other Mach based systems (OSF/1, OS X, etc) is to suspend > all other threads using `thread_suspend' and then run GC from whichever > thread is the first to discover that the consing threshold has been > exceeded. Unix systems typically provide other platform specific > functions to suspend threads or LWPs. > > As a consequence of this approach, GC can take place even if those other > threads hold pointers to relocatable string data and buffer text. I've > experimentally verified that this is rare, and that not compacting > string blocks which are referenced from the stack or in registers > doesn't significantly affect string data fragmentation. Sounds not 100% reliable. May it be possible to restart blocking operation if GC is triggered in the middle of it? What I have in mind is something similar to (setq sucess nil) (while (not success) (while-no-input (do-staff-that-knows-it-can-be-restarted-sometimes) (setq sucess t))) but for low-level code that requires object locks. -- Ihor Radchenko // yantar92, Org mode contributor, Learn more about Org mode at . Support Org development at , or support my work at