From 2e1f204d012f02895573066de58ba62a544d91d2 Mon Sep 17 00:00:00 2001 From: GNU Hurd web pages engine Date: Sun, 12 Jan 2014 08:39:54 +0100 Subject: Uncommitted changes. ... in darnassus:~hurd-web/public_html.workspace/. --- open_issues/Upstart.mdwn | 61 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 open_issues/Upstart.mdwn (limited to 'open_issues/Upstart.mdwn') diff --git a/open_issues/Upstart.mdwn b/open_issues/Upstart.mdwn new file mode 100644 index 00000000..49e48403 --- /dev/null +++ b/open_issues/Upstart.mdwn @@ -0,0 +1,61 @@ +[[!meta copyright="Copyright © 2013 Free Software Foundation, Inc."]] + +[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable +id="license" text="Permission is granted to copy, distribute and/or modify this +document under the terms of the GNU Free Documentation License, Version 1.2 or +any later version published by the Free Software Foundation; with no Invariant +Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license +is included in the section entitled [[GNU Free Documentation +License|/fdl]]."]]"""]] + +Upstart is an event based init system that is GPL licensed, however upstream +contributions are under a CLA that permits proprietary relicensing. + +As of Jan 2 2013, Debian is considering adopting Upstart as an init system on +GNU/Linux, and on GNU/kFreeBSD when the port to kFreeBSD is finished. + +The following are the words of Colin Watson on the debian-ctte@lists.debian.org +mailing list and list the requirements of a potential HURD port: + +>I haven't looked at this in much detail, and I suspect Dimitri hasn't +yet although IIRC he did express some interest in doing so. But I +haven't seen anyone else try to outline the scope of a port, so let me +try to do so for the sake of general understanding. As far as I know, +the hardest parts would be inotify, ptrace, and prctl +(PR_SET_CHILD_SUBREAPER). + +>inotify is used to notice changes to configuration files. This is +certainly helpful for users, but it isn't critical as "initctl +reload-configuration" works without it. We could probably do without +this with the aid of a dpkg trigger. + +>ptrace is used for "expect fork" and "expect daemon"; as I indicated in +another post, I think it would be preferable to avoid these in Debian +and quite possibly to compile them out. (This would mean we wouldn't be +able to translate Ubuntu jobs quite as directly, and a number of +important jobs would definitely need to be changed, but the conversion +isn't usually particularly difficult.) + +>prctl (PR_SET_CHILD_SUBREAPER) is used to make SIGCHLD notification work +properly when Upstart is supervising a user session. This isn't a +required feature and could easily be compiled out until suitable kernel +support is available (this actually seems like the sort of thing that +could be done in the Hurd without too much difficulty, but I haven't +looked into it). If absent, it might well impede the ability to do an +advanced desktop port, but it wouldn't get in the way of porting the +bulk of services. + +>There might also be odds and ends around the details of wait status +handling. + +inotify seems to be a feature that is often used in GNU/Linux programs, and +implementing the feature in the HURD seems like a better and more rewarding +option than porting the code in Upstart. + +Although many daemons double fork, that behavior seems to be dying out, and +one can comfortably ignore the "expect fork/daemon" functionality of Upstart +(and compile it out). + +[[!inline pages=tag raw=yes feeds=no]] + +[[!tag open_issue_porting]] -- cgit v1.2.3