From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: Is there any easy way to fork in elisp? Why not? Date: Thu, 28 Oct 2021 18:06:03 -0400 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="5926"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) Cc: emacs-devel@gnu.org To: Rudi C Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Fri Oct 29 00:15:44 2021 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 1mgDgV-0001Jw-KM for ged-emacs-devel@m.gmane-mx.org; Fri, 29 Oct 2021 00:15:43 +0200 Original-Received: from localhost ([::1]:44520 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mgDgU-0003KH-2L for ged-emacs-devel@m.gmane-mx.org; Thu, 28 Oct 2021 18:15:42 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:45934) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mgDXJ-00038q-Tj for emacs-devel@gnu.org; Thu, 28 Oct 2021 18:06:17 -0400 Original-Received: from mailscanner.iro.umontreal.ca ([132.204.25.50]:63850) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mgDXF-0000nz-B0 for emacs-devel@gnu.org; Thu, 28 Oct 2021 18:06:13 -0400 Original-Received: from pmg2.iro.umontreal.ca (localhost.localdomain [127.0.0.1]) by pmg2.iro.umontreal.ca (Proxmox) with ESMTP id 9036880677; Thu, 28 Oct 2021 18:06:06 -0400 (EDT) Original-Received: from mail01.iro.umontreal.ca (unknown [172.31.2.1]) by pmg2.iro.umontreal.ca (Proxmox) with ESMTP id E9164801AA; Thu, 28 Oct 2021 18:06:04 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=iro.umontreal.ca; s=mail; t=1635458764; bh=24CFrUoSdpziJpNJZWAUWHHSEHUsgHYrq+xyL/HJX7g=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=gHjLH0El2aLuAOz07M3myjAme/vbw2Z0MM0J+n7AmkYH7DKlkkSOEux5dGi++AOAq 2VGz7YX521BYWyqwM0nLDcVtasiK6xnYYJ2Ig/kGOlnonw33VZhS0RuOBB+1ErRERK ICthKmEa6rQBcutdYSCFLvQrCQ48PRUE786PpD0r+BDUm2HLqF3edTlifz9vEzRDlJ 0ijEnIS7DRMz32baZeQVHqbXsS351M8fl4gINTDgb+FofRHkaiiAfDyoxvEGuneswd Vs97KZ6Qn/S50XhietUJRGl3FKfXaapHBognZ6Hd3DrqH4CPm5i1mgBJU0gy6mXbf9 TKOFpIgJdLAKA== Original-Received: from pastel (unknown [45.72.241.23]) by mail01.iro.umontreal.ca (Postfix) with ESMTPSA id BE4871201B2; Thu, 28 Oct 2021 18:06:04 -0400 (EDT) In-Reply-To: (Rudi C.'s message of "Tue, 26 Oct 2021 16:14:37 +0330") Received-SPF: pass client-ip=132.204.25.50; envelope-from=monnier@iro.umontreal.ca; helo=mailscanner.iro.umontreal.ca X-Spam_score_int: -42 X-Spam_score: -4.3 X-Spam_bar: ---- X-Spam_report: (-4.3 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 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" Xref: news.gmane.io gmane.emacs.devel:278150 Archived-At: > If the server could just fork, eval the request, return it, and die, > everything would be easy and painless. > > The fork API could be: > ``` > (let-fork ((some_val (expensive_compute)) ...) > (lambda() > (message "Computed: %s" some_val))) > ``` We should indeed add such support in core. Currently the `async` package offers such functionality, but I think this belongs in core. More generally a kind of "Emacs batch server" will be useful. Something similar to the server.el but whose purpose would be to launch independent/fresh batch Emacs sessions efficiently. A long time ago I suggested to add support for the `fork` POSIX primitive which could be ideal for that, but AFAIK it's hard to provide such a functionality in w32, so we'd want the Lisp-level API not to be tied to the semantics of POSIX `fork`. Stefan