Files
mpd/src/lib/alsa/NonBlock.cxx

118 lines
3.1 KiB
C++

/*
* Copyright 2003-2021 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "NonBlock.hxx"
#include "Error.hxx"
#include "event/MultiSocketMonitor.hxx"
#include "util/RuntimeError.hxx"
Event::Duration
AlsaNonBlockPcm::PrepareSockets(MultiSocketMonitor &m, snd_pcm_t *pcm)
{
int count = snd_pcm_poll_descriptors_count(pcm);
if (count <= 0) {
if (count == 0)
throw std::runtime_error("snd_pcm_poll_descriptors_count() failed");
else
throw Alsa::MakeError(count, "snd_pcm_poll_descriptors_count() failed");
}
struct pollfd *pfds = pfd_buffer.Get(count);
count = snd_pcm_poll_descriptors(pcm, pfds, count);
if (count <= 0) {
if (count == 0)
throw std::runtime_error("snd_pcm_poll_descriptors() failed");
else
throw Alsa::MakeError(count, "snd_pcm_poll_descriptors() failed");
}
m.ReplaceSocketList(pfds, count);
return Event::Duration(-1);
}
void
AlsaNonBlockPcm::DispatchSockets(MultiSocketMonitor &m,
snd_pcm_t *pcm)
{
int count = snd_pcm_poll_descriptors_count(pcm);
if (count <= 0)
return;
const auto pfds = pfd_buffer.Get(count), end = pfds + count;
auto *i = pfds;
m.ForEachReturnedEvent([&i, end](SocketDescriptor s, unsigned events){
if (i >= end)
return;
i->fd = s.Get();
i->events = i->revents = events;
++i;
});
unsigned short dummy;
int err = snd_pcm_poll_descriptors_revents(pcm, pfds, i - pfds, &dummy);
if (err < 0)
throw Alsa::MakeError(err, "snd_pcm_poll_descriptors_revents() failed");
}
Event::Duration
AlsaNonBlockMixer::PrepareSockets(MultiSocketMonitor &m, snd_mixer_t *mixer) noexcept
{
int count = snd_mixer_poll_descriptors_count(mixer);
if (count <= 0) {
m.ClearSocketList();
return Event::Duration(-1);
}
struct pollfd *pfds = pfd_buffer.Get(count);
count = snd_mixer_poll_descriptors(mixer, pfds, count);
if (count < 0)
count = 0;
m.ReplaceSocketList(pfds, count);
return Event::Duration(-1);
}
void
AlsaNonBlockMixer::DispatchSockets(MultiSocketMonitor &m,
snd_mixer_t *mixer) noexcept
{
int count = snd_mixer_poll_descriptors_count(mixer);
if (count <= 0)
return;
const auto pfds = pfd_buffer.Get(count), end = pfds + count;
auto *i = pfds;
m.ForEachReturnedEvent([&i, end](SocketDescriptor s, unsigned events){
if (i >= end)
return;
i->fd = s.Get();
i->events = i->revents = events;
++i;
});
unsigned short dummy;
snd_mixer_poll_descriptors_revents(mixer, pfds, i - pfds, &dummy);
}