It may be useful to pipe the output to another program.
Fixes: https://github.com/alsa-project/alsa-utils/pull/109
Signed-off-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Take the card iterator idea from the monitor code and
use it for all card loops. It reduces the code duplications
and makes things easy to review.
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
The timeout wasn't really being used for anything; disabling it should
reduce idle energy consumption slightly.
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Tested-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Previously, things like attaching strace to a running 'alsactl monitor'
process would cause it to exit.
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Tested-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
In a mode of 'monitor, event loop runs to dispatch asynchronous event
emitted by control node. In this case, UNIX signal is used to terminate
the event loop.
This commit uses signalfd to catch the UNIX signal.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
At present, plug-and-play is not supported in a mode of 'monitor',
thus new sound card is not handled during runtime. This is not happy.
This commit uses Linux-specific inotify(7) to monitor '/dev/snd'
directory. When some files are newly added to the directory,
event dispatcher is suspended. Event sources are scanned again and the
dispatcher continue to run.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Once sound card becomes disconnection state, corresponding control node
becomes to emit error event for listeners. When catching this type of
event, event dispatcher should stop observation of the node. However,
at present, a mode of monitor can't handle this correctly. As a result,
poll(2) is executed quite frequently in loop with no wait. This results
100% consumption of CPU time.
This commit takes the dispatcher to remove the node from observation
list when detecting the disconnection state.
Reported-by: Thomas Gläßle <thomas@coldfix.de>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
In former commits, handlers of control node are maintained by link list,
instead of one-dimensional array.
This commit obsoletes the array and split source preparation to a
function.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
In a previous commit, handlers of control nodes are maintained by link
list.
This commit uses the list to register/unregister event sources to
dispatcher.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
At present, handlers for control nodes are maintained by one-dimensional
array. This is not necessarily useful to maintain handlers with
associated information.
This commit adds link-list for the maintenance.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Linux kernel supports unique system call; epoll(7). This allows
applications to make associations for descriptor-unique data in a
easy way.
This commit uses epoll(7) instead of poll(2) for this point.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
In a mode of 'monitor', when given no argument, all of available control
node is observed for their events. At present, discovering the nodes is
done according to sound card number, instead of listing nodes in
configuration space of alsa-lib.
This commit adds a structure to discover sound cards with a simple
interface.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
In a mode of 'monitor', an event loop runs.
This commit applies a small refactoring to splits the loop into a
function for readability.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
SND_CTL_EVENT_MASK_REMOVE has to be checked at first and ignore the
rest if it matches. Suggested by Clemens.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
