7d579e7400
Avoid another potential deadlock: if no file descriptors are registered, our non-blocking ALSA code cannot ever work.
72 lines
2.2 KiB
C++
72 lines
2.2 KiB
C++
/*
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* Copyright 2003-2017 The Music Player Daemon Project
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* http://www.musicpd.org
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include "config.h"
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#include "NonBlock.hxx"
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#include "event/MultiSocketMonitor.hxx"
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#include "util/RuntimeError.hxx"
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std::chrono::steady_clock::duration
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PrepareAlsaPcmSockets(MultiSocketMonitor &m, snd_pcm_t *pcm,
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ReusableArray<pollfd> &pfd_buffer)
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{
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int count = snd_pcm_poll_descriptors_count(pcm);
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if (count <= 0) {
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if (count == 0)
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throw std::runtime_error("snd_pcm_poll_descriptors_count() failed");
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else
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throw FormatRuntimeError("snd_pcm_poll_descriptors_count() failed: %s",
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snd_strerror(-count));
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}
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struct pollfd *pfds = pfd_buffer.Get(count);
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count = snd_pcm_poll_descriptors(pcm, pfds, count);
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if (count <= 0) {
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if (count == 0)
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throw std::runtime_error("snd_pcm_poll_descriptors() failed");
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else
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throw FormatRuntimeError("snd_pcm_poll_descriptors() failed: %s",
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snd_strerror(-count));
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}
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m.ReplaceSocketList(pfds, count);
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return std::chrono::steady_clock::duration(-1);
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}
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std::chrono::steady_clock::duration
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PrepareAlsaMixerSockets(MultiSocketMonitor &m, snd_mixer_t *mixer,
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ReusableArray<pollfd> &pfd_buffer) noexcept
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{
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int count = snd_mixer_poll_descriptors_count(mixer);
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if (count <= 0) {
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m.ClearSocketList();
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return std::chrono::steady_clock::duration(-1);
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}
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struct pollfd *pfds = pfd_buffer.Get(count);
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count = snd_mixer_poll_descriptors(mixer, pfds, count);
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if (count < 0)
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count = 0;
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m.ReplaceSocketList(pfds, count);
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return std::chrono::steady_clock::duration(-1);
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}
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