When child `gsettings-helper` terminates prematurely, unconditionally reading
from child pipe fails in a busy loop until child process is reaped.
Fix this by terminating module upon PA_IO_EVENT_HANGUP or PA_IO_EVENT_ERROR.
Part-of: <https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/merge_requests/600>
Having G_MESSAGES_DEBUG=all set in the environment (a normal thing to do
when debugging Gnome troubles) causes gsettings-helper to emit a bunch
of helpful gnome debug logs (which is good), but before this change they
were printed on stdout rather than stderr (which was bad!). Rather than
going somewhere the user could see, these log messages were being sent
to the pulesaudio server and interpreted as the src/modules/stdin-util.c
protocol. pulseadio waits to see a '!' message from gsettings-helper
before continuing startup. With the log messages mixed in messing up
the stdin-util protocol, pulseaudio never saw the '!' message, and so
never completed startup.
This simple fix relies on a recent glib > 2.68 (Mar 2021), so builds
against old versions of glib will still have this problem! We consider
this good enough until some complains otherwise.
Fixes: https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/issues/1222
Part-of: <https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/merge_requests/579>
This was being done automatically by autotools, now we need to manually
specify this for each executable/library with a dependency in a
non-standard directory.
It is helpful to improve reproducibility build [1] since
PA_SRCDIR/PA_BUILDDIR contains build path,
--disable-running-from-build-tree could drop these macros at
precompilation.
[1] https://reproducible-builds.org/
Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
This was originally planned to be done by paprefs when it starts, but
since the schema is now fully controlled by pulseaudio, it makes sense
to run the conversion from pulseaudio instead.
g_settings_get_child() returns a new GSettings object that needs to be
freed when it's not used any more. This patch collects all the childern
to a GPtrArray and frees them at the end of main(). They can't be freed
earlier, because that would prevent the "changed" signals from being
delivered.
The removed g_signal_connect() call didn't make sense. The callback
expects to be called when individual module groups are changed, not when
the top level object is changed. Also, module_group_callback() expects
user_data to be non-NULL, but here it was set to NULL.
According to the documentation of g_settings_list_children(), the listed
children may be removed at any time, so g_settings_get_child() may
return NULL. This is probably very unlikely to happen in practice, but
it's good to check anyway.
It is confusing if there's a thing named "module" which defines up to 10
modules to load. Calling the thing a "module group" instead should make
it easier to understand.
Originally the idea was to provide the "modules" schema with paprefs,
but since module-gsettings refers to the "modules" schema in its code,
that would make module-gsettings depend on paprefs, which is not good.
Now all schemas are provided by module-gsettings, so the paprefs
dependency is avoided. Unfortunately this means that if paprefs is
modified to load some new modules, the schema in pulseaudio needs to be
updated as well.
GConf is deprecated, and distributions are removing it. paprefs depends
on GConf, so in order to avoid paprefs getting removed as well, paprefs
has to be changed to use something else than GConf. GSettings is the
easiest alternative to migrate to, although it has the same problems
that GConf had: no support for system mode or networking.
This patch takes the non-GConf specific code from module-gconf and puts
it in stdin-util.[ch], which is then reused by module-gsettings.
module-gsettings is designed to be very similar to module-gconf.
Migration is expected to happen as follows: Distributions update
PulseAudio and paprefs at the same time, or first PulseAudio and then
paprefs. paprefs depends on module-gsettings, and module-gsettings
conflicts with module-gconf. Therefore module-gconf gets automatically
removed during the paprefs update. After the update an old PulseAudio is
likely to be running with module-gconf loaded. If the user tries to use
paprefs during this period, whatever the user does in paprefs won't have
any effect until PulseAudio is restarted (probably by a reboot or
relogin). This is not ideal, but will have to do.
When module-gsettings is loaded, it runs gsettings-data-convert
(implemented in a later patch). That will copy the settings from GConf
to GSettings. If gsettings-data-convert is not available (it's part of
GConf, so it may have already been uninstalled), then any previous
paprefs settings are lost.
