Follow-ups for 74c4231ce5.
Previously, the path is obtained from the fd, but it is closed in
sd_event_loop() to unpin the filesystem.
So, let's save the path when the event source is created, and make
sd_event_source_get_inotify_path() simply read it.
This tries to add information about when each option was added. It goes
back to version 183.
The version info is included from a separate file to allow generating it,
which would allow more control on the formatting of the final output.
sd-event objects use hashmaps, which use module-global state, so it is not safe
to pass a sd-event object created by a module instance to another module instance
(e.g.: when two libraries static linking sd-event are pulled in a single process).
Initialize a random per-module origin id and store it in the object, and compare
it when entering a public API, and error out if they don't match, together with
the PID.
Also, document this functionality more prominently, including with a
reference from sd_event_exit().
This is mostly to make things complete, as previously we supported NULL
callbacks only in _add_time() and _add_signal(). However, I think this
makes snese for IO event sources too (think: when some fd such as a pipe
end sees SIGHUP or so, exit), as well as defer or post event sources (i.e. exit
once we got nothing else to do). This also adds support for inotify
event sources, simply to complete things (I can't see the immediate use,
but maybe someone else comes up with it).
The only event source type that doesn't allow callback=NULL now are exit
callbacks, but for them they make little sense, as the event loop is
exiting then anyway.
Let's make sure we get back to 100% man page documentation coverage of
our sd-event APIs. We are bad enough at the others, let's get these ones
right at least.
Logically, this is better, because we're describing a subset of possible
return values. Visually this also looks quite good because groff renders
refsect2 much less prominently.
Also rewrap things, add <constant> in various places, fix some typos.
The "include" files had type "book" for some raeason. I don't think this
is meaningful. Let's just use the same everywhere.
$ perl -i -0pe 's^..DOCTYPE (book|refentry) PUBLIC "-//OASIS//DTD DocBook XML V4.[25]//EN"\s+"http^<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"\n "http^gms' man/*.xml
No need to waste space, and uniformity is good.
$ perl -i -0pe 's|\n+<!--\s*SPDX-License-Identifier: LGPL-2.1..\s*-->|\n<!-- SPDX-License-Identifier: LGPL-2.1+ -->|gms' man/*.xml
