OutputAll: convert to class, move instance to class Partition

Another big chunk of code for multi-player support.

10 files changed, 791 insertions, 815 deletions

diff --git a/src/output/MultipleOutputs.cxx b/src/output/MultipleOutputs.cxx
new file mode 100644
index 000000000..50f686843
--- /dev/null
+++ b/src/output/MultipleOutputs.cxx
@@ -0,0 +1,477 @@
+/*
+ * Copyright (C) 2003-2014 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 "config.h"
+#include "MultipleOutputs.hxx"
+#include "PlayerControl.hxx"
+#include "OutputInternal.hxx"
+#include "OutputControl.hxx"
+#include "OutputError.hxx"
+#include "MusicBuffer.hxx"
+#include "MusicPipe.hxx"
+#include "MusicChunk.hxx"
+#include "system/FatalError.hxx"
+#include "util/Error.hxx"
+#include "config/ConfigData.hxx"
+#include "config/ConfigGlobal.hxx"
+#include "config/ConfigOption.hxx"
+#include "notify.hxx"
+
+#include <assert.h>
+#include <string.h>
+
+MultipleOutputs::MultipleOutputs()
+	:buffer(nullptr), pipe(nullptr),
+	 elapsed_time(-1)
+{
+}
+
+MultipleOutputs::~MultipleOutputs()
+{
+	for (auto i : outputs) {
+		audio_output_disable(i);
+		audio_output_finish(i);
+	}
+}
+
+static audio_output *
+LoadOutput(PlayerControl &pc, const config_param &param)
+{
+	Error error;
+	audio_output *output = audio_output_new(param, pc, error);
+	if (output == nullptr) {
+		if (param.line > 0)
+			FormatFatalError("line %i: %s",
+					 param.line,
+					 error.GetMessage());
+		else
+			FatalError(error);
+	}
+
+	return output;
+}
+
+void
+MultipleOutputs::Configure(PlayerControl &pc)
+{
+	const config_param *param = nullptr;
+	while ((param = config_get_next_param(CONF_AUDIO_OUTPUT,
+					      param)) != nullptr) {
+		auto output = LoadOutput(pc, *param);
+		if (FindByName(output->name) != nullptr)
+			FormatFatalError("output devices with identical "
+					 "names: %s", output->name);
+
+		outputs.push_back(output);
+	}
+
+	if (outputs.empty()) {
+		/* auto-detect device */
+		const config_param empty;
+		auto output = LoadOutput(pc, empty);
+		outputs.push_back(output);
+	}
+}
+
+audio_output *
+MultipleOutputs::FindByName(const char *name) const
+{
+	for (auto i : outputs)
+		if (strcmp(i->name, name) == 0)
+			return i;
+
+	return nullptr;
+}
+
+void
+MultipleOutputs::EnableDisable()
+{
+	for (auto ao : outputs) {
+		bool enabled;
+
+		ao->mutex.lock();
+		enabled = ao->really_enabled;
+		ao->mutex.unlock();
+
+		if (ao->enabled != enabled) {
+			if (ao->enabled)
+				audio_output_enable(ao);
+			else
+				audio_output_disable(ao);
+		}
+	}
+}
+
+bool
+MultipleOutputs::AllFinished() const
+{
+	for (auto ao : outputs) {
+		const ScopeLock protect(ao->mutex);
+		if (audio_output_is_open(ao) &&
+		    !audio_output_command_is_finished(ao))
+			return false;
+	}
+
+	return true;
+}
+
+void
+MultipleOutputs::WaitAll()
+{
+	while (!AllFinished())
+		audio_output_client_notify.Wait();
+}
+
+void
+MultipleOutputs::AllowPlay()
+{
+	for (auto ao : outputs)
+		audio_output_allow_play(ao);
+}
+
+static void
+audio_output_reset_reopen(struct audio_output *ao)
+{
+	const ScopeLock protect(ao->mutex);
+
+	ao->fail_timer.Reset();
+}
+
+void
+MultipleOutputs::ResetReopen()
+{
+	for (auto ao : outputs)
+		audio_output_reset_reopen(ao);
+}
+
+bool
+MultipleOutputs::Update()
+{
+	bool ret = false;
+
+	if (!input_audio_format.IsDefined())
+		return false;
+
+	for (auto ao : outputs)
+		ret = audio_output_update(ao, input_audio_format, *pipe)
+			|| ret;
+
+	return ret;
+}
+
+void
+MultipleOutputs::SetReplayGainMode(ReplayGainMode mode)
+{
+	for (auto ao : outputs)
+		audio_output_set_replay_gain_mode(ao, mode);
+}
+
+bool
+MultipleOutputs::Play(music_chunk *chunk, Error &error)
+{
+	assert(buffer != nullptr);
+	assert(pipe != nullptr);
+	assert(chunk != nullptr);
+	assert(chunk->CheckFormat(input_audio_format));
+
+	if (!Update()) {
+		/* TODO: obtain real error */
+		error.Set(output_domain, "Failed to open audio output");
+		return false;
+	}
+
+	pipe->Push(chunk);
+
+	for (auto ao : outputs)
+		audio_output_play(ao);
+
+	return true;
+}
+
+bool
+MultipleOutputs::Open(const AudioFormat audio_format,
+		      MusicBuffer &_buffer,
+		      Error &error)
+{
+	bool ret = false, enabled = false;
+
+	assert(buffer == nullptr || buffer == &_buffer);
+	assert((pipe == nullptr) == (buffer == nullptr));
+
+	buffer = &_buffer;
+
+	/* the audio format must be the same as existing chunks in the
+	   pipe */
+	assert(pipe == nullptr || pipe->CheckFormat(audio_format));
+
+	if (pipe == nullptr)
+		pipe = new MusicPipe();
+	else
+		/* if the pipe hasn't been cleared, the the audio
+		   format must not have changed */
+		assert(pipe->IsEmpty() || audio_format == input_audio_format);
+
+	input_audio_format = audio_format;
+
+	ResetReopen();
+	EnableDisable();
+	Update();
+
+	for (auto ao : outputs) {
+		if (ao->enabled)
+			enabled = true;
+
+		if (ao->open)
+			ret = true;
+	}
+
+	if (!enabled)
+		error.Set(output_domain, "All audio outputs are disabled");
+	else if (!ret)
+		/* TODO: obtain real error */
+		error.Set(output_domain, "Failed to open audio output");
+
+	if (!ret)
+		/* close all devices if there was an error */
+		Close();
+
+	return ret;
+}
+
+/**
+ * Has the specified audio output already consumed this chunk?
+ */
+gcc_pure
+static bool
+chunk_is_consumed_in(const struct audio_output *ao,
+		     gcc_unused const MusicPipe *pipe,
+		     const struct music_chunk *chunk)
+{
+	if (!ao->open)
+		return true;
+
+	if (ao->chunk == nullptr)
+		return false;
+
+	assert(chunk == ao->chunk || pipe->Contains(ao->chunk));
+
+	if (chunk != ao->chunk) {
+		assert(chunk->next != nullptr);
+		return true;
+	}
+
+	return ao->chunk_finished && chunk->next == nullptr;
+}
+
+bool
+MultipleOutputs::IsChunkConsumed(const music_chunk *chunk) const
+{
+	for (auto ao : outputs) {
+		const ScopeLock protect(ao->mutex);
+		if (!chunk_is_consumed_in(ao, pipe, chunk))
+			return false;
+	}
+
+	return true;
+}
+
+inline void
+MultipleOutputs::ClearTailChunk(gcc_unused const struct music_chunk *chunk,
+				bool *locked)
+{
+	assert(chunk->next == nullptr);
+	assert(pipe->Contains(chunk));
+
+	for (unsigned i = 0, n = outputs.size(); i != n; ++i) {
+		audio_output *ao = outputs[i];
+
+		/* this mutex will be unlocked by the caller when it's
+		   ready */
+		ao->mutex.lock();
+		locked[i] = ao->open;
+
+		if (!locked[i]) {
+			ao->mutex.unlock();
+			continue;
+		}
+
+		assert(ao->chunk == chunk);
+		assert(ao->chunk_finished);
+		ao->chunk = nullptr;
+	}
+}
+
+unsigned
+MultipleOutputs::Check()
+{
+	const struct music_chunk *chunk;
+	bool is_tail;
+	struct music_chunk *shifted;
+	bool locked[outputs.size()];
+
+	assert(buffer != nullptr);
+	assert(pipe != nullptr);
+
+	while ((chunk = pipe->Peek()) != nullptr) {
+		assert(!pipe->IsEmpty());
+
+		if (!IsChunkConsumed(chunk))
+			/* at least one output is not finished playing
+			   this chunk */
+			return pipe->GetSize();
+
+		if (chunk->length > 0 && chunk->times >= 0.0)
+			/* only update elapsed_time if the chunk
+			   provides a defined value */
+			elapsed_time = chunk->times;
+
+		is_tail = chunk->next == nullptr;
+		if (is_tail)
+			/* this is the tail of the pipe - clear the
+			   chunk reference in all outputs */
+			ClearTailChunk(chunk, locked);
+
+		/* remove the chunk from the pipe */
+		shifted = pipe->Shift();
+		assert(shifted == chunk);
+
+		if (is_tail)
+			/* unlock all audio outputs which were locked
+			   by clear_tail_chunk() */
+			for (unsigned i = 0, n = outputs.size(); i != n; ++i)
+				if (locked[i])
+					outputs[i]->mutex.unlock();
+
+		/* return the chunk to the buffer */
+		buffer->Return(shifted);
+	}
+
+	return 0;
+}
+
+bool
+MultipleOutputs::Wait(PlayerControl &pc, unsigned threshold)
+{
+	pc.Lock();
+
+	if (Check() < threshold) {
+		pc.Unlock();
+		return true;
+	}
+
+	pc.Wait();
+	pc.Unlock();
+
+	return Check() < threshold;
+}
+
+void
+MultipleOutputs::Pause()
+{
+	Update();
+
+	for (auto ao : outputs)
+		audio_output_pause(ao);
+
+	WaitAll();
+}
+
+void
+MultipleOutputs::Drain()
+{
+	for (auto ao : outputs)
+		audio_output_drain_async(ao);
+
+	WaitAll();
+}
+
+void
+MultipleOutputs::Cancel()
+{
+	/* send the cancel() command to all audio outputs */
+
+	for (auto ao : outputs)
+		audio_output_cancel(ao);
+
+	WaitAll();
+
+	/* clear the music pipe and return all chunks to the buffer */
+
+	if (pipe != nullptr)
+		pipe->Clear(*buffer);
+
+	/* the audio outputs are now waiting for a signal, to
+	   synchronize the cleared music pipe */
+
+	AllowPlay();
+
+	/* invalidate elapsed_time */
+
+	elapsed_time = -1.0;
+}
+
+void
+MultipleOutputs::Close()
+{
+	for (auto ao : outputs)
+		audio_output_close(ao);
+
+	if (pipe != nullptr) {
+		assert(buffer != nullptr);
+
+		pipe->Clear(*buffer);
+		delete pipe;
+		pipe = nullptr;
+	}
+
+	buffer = nullptr;
+
+	input_audio_format.Clear();
+
+	elapsed_time = -1.0;
+}
+
+void
+MultipleOutputs::Release()
+{
+	for (auto ao : outputs)
+		audio_output_release(ao);
+
+	if (pipe != nullptr) {
+		assert(buffer != nullptr);
+
+		pipe->Clear(*buffer);
+		delete pipe;
+		pipe = nullptr;
+	}
+
+	buffer = nullptr;
+
+	input_audio_format.Clear();
+
+	elapsed_time = -1.0;
+}
+
+void
+MultipleOutputs::SongBorder()
+{
+	/* clear the elapsed_time pointer at the beginning of a new
+	   song */
+	elapsed_time = 0.0;
+}
diff --git a/src/output/MultipleOutputs.hxx b/src/output/MultipleOutputs.hxx
new file mode 100644
index 000000000..e1a8602a9
--- /dev/null
+++ b/src/output/MultipleOutputs.hxx
@@ -0,0 +1,271 @@
+/*
+ * Copyright (C) 2003-2014 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.
+ */
+
+/*
+ * Functions for dealing with all configured (enabled) audion outputs
+ * at once.
+ *
+ */
+
+#ifndef OUTPUT_ALL_H
+#define OUTPUT_ALL_H
+
+#include "AudioFormat.hxx"
+#include "ReplayGainInfo.hxx"
+#include "Compiler.h"
+
+#include <vector>
+
+#include <assert.h>
+
+struct AudioFormat;
+class MusicBuffer;
+class MusicPipe;
+struct music_chunk;
+struct PlayerControl;
+struct audio_output;
+class Error;
+
+class MultipleOutputs {
+	std::vector<audio_output *> outputs;
+
+	AudioFormat input_audio_format;
+
+	/**
+	 * The #MusicBuffer object where consumed chunks are returned.
+	 */
+	MusicBuffer *buffer;
+
+	/**
+	 * The #MusicPipe object which feeds all audio outputs.  It is
+	 * filled by audio_output_all_play().
+	 */
+	MusicPipe *pipe;
+
+	/**
+	 * The "elapsed_time" stamp of the most recently finished
+	 * chunk.
+	 */
+	float elapsed_time;
+
+public:
+	/**
+	 * Load audio outputs from the configuration file and
+	 * initialize them.
+	 */
+	MultipleOutputs();
+	~MultipleOutputs();
+
+	void Configure(PlayerControl &pc);
+
+	/**
+	 * Returns the total number of audio output devices, including
+	 * those which are disabled right now.
+	 */
+	gcc_pure
+	unsigned Size() const {
+		return outputs.size();
+	}
+
+	/**
+	 * Returns the "i"th audio output device.
+	 */
+	const audio_output &Get(unsigned i) const {
+		assert(i < Size());
+
+		return *outputs[i];
+	}
+
+	audio_output &Get(unsigned i) {
+		assert(i < Size());
+
+		return *outputs[i];
+	}
+
+	/**
+	 * Returns the audio output device with the specified name.
+	 * Returns nullptr if the name does not exist.
+	 */
+	gcc_pure
+	audio_output *FindByName(const char *name) const;
+
+	/**
+	 * Checks the "enabled" flag of all audio outputs, and if one has
+	 * changed, commit the change.
+	 */
+	void EnableDisable();
+
+	/**
+	 * Opens all audio outputs which are not disabled.
+	 *
+	 * @param audio_format the preferred audio format
+	 * @param buffer the #music_buffer where consumed #music_chunk objects
+	 * should be returned
+	 * @return true on success, false on failure
+	 */
+	bool Open(const AudioFormat audio_format, MusicBuffer &_buffer,
+		  Error &error);
+
+	/**
+	 * Closes all audio outputs.
+	 */
+	void Close();
+
+	/**
+	 * Closes all audio outputs.  Outputs with the "always_on"
+	 * flag are put into pause mode.
+	 */
+	void Release();
+
+	void SetReplayGainMode(ReplayGainMode mode);
+
+	/**
+	 * Enqueue a #music_chunk object for playing, i.e. pushes it to a
+	 * #MusicPipe.
+	 *
+	 * @param chunk the #music_chunk object to be played
+	 * @return true on success, false if no audio output was able to play
+	 * (all closed then)
+	 */
+	bool Play(music_chunk *chunk, Error &error);
+
+	/**
+	 * Checks if the output devices have drained their music pipe, and
+	 * returns the consumed music chunks to the #music_buffer.
+	 *
+	 * @return the number of chunks to play left in the #MusicPipe
+	 */
+	unsigned Check();
+
+	/**
+	 * Checks if the size of the #MusicPipe is below the #threshold.  If
+	 * not, it attempts to synchronize with all output threads, and waits
+	 * until another #music_chunk is finished.
+	 *
+	 * @param threshold the maximum number of chunks in the pipe
+	 * @return true if there are less than #threshold chunks in the pipe
+	 */
+	bool Wait(PlayerControl &pc, unsigned threshold);
+
+	/**
+	 * Puts all audio outputs into pause mode.  Most implementations will
+	 * simply close it then.
+	 */
+	void Pause();
+
+	/**
+	 * Drain all audio outputs.
+	 */
+	void Drain();
+
+	/**
+	 * Try to cancel data which may still be in the device's buffers.
+	 */
+	void Cancel();
+
+	/**
+	 * Indicate that a new song will begin now.
+	 */
+	void SongBorder();
+
+	/**
+	 * Returns the "elapsed_time" stamp of the most recently finished
+	 * chunk.  A negative value is returned when no chunk has been
+	 * finished yet.
+	 */
+	gcc_pure
+	float GetElapsedTime() const {
+		return elapsed_time;
+	}
+
+	/**
+	 * Returns the average volume of all available mixers (range
+	 * 0..100).  Returns -1 if no mixer can be queried.
+	 */
+	gcc_pure
+	int GetVolume() const;
+
+	/**
+	 * Sets the volume on all available mixers.
+	 *
+	 * @param volume the volume (range 0..100)
+	 * @return true on success, false on failure
+	 */
+	bool SetVolume(unsigned volume);
+
+	/**
+	 * Similar to GetVolume(), but gets the volume only for
+	 * software mixers.  See #software_mixer_plugin.  This
+	 * function fails if no software mixer is configured.
+	 */
+	gcc_pure
+	int GetSoftwareVolume() const;
+
+	/**
+	 * Similar to SetVolume(), but sets the volume only for
+	 * software mixers.  See #software_mixer_plugin.  This
+	 * function cannot fail, because the underlying software
+	 * mixers cannot fail either.
+	 */
+	void SetSoftwareVolume(unsigned volume);
+
+private:
+	/**
+	 * Determine if all (active) outputs have finished the current
+	 * command.
+	 */
+	gcc_pure
+	bool AllFinished() const;
+
+	void WaitAll();
+
+	/**
+	 * Signals all audio outputs which are open.
+	 */
+	void AllowPlay();
+
+	/**
+	 * Resets the "reopen" flag on all audio devices.  MPD should
+	 * immediately retry to open the device instead of waiting for
+	 * the timeout when the user wants to start playback.
+	 */
+	void ResetReopen();
+
+	/**
+	 * Opens all output devices which are enabled, but closed.
+	 *
+	 * @return true if there is at least open output device which
+	 * is open
+	 */
+	bool Update();
+
+	/**
+	 * Has this chunk been consumed by all audio outputs?
+	 */
+	bool IsChunkConsumed(const music_chunk *chunk) const;
+
+	/**
+	 * There's only one chunk left in the pipe (#pipe), and all
+	 * audio outputs have consumed it already.  Clear the
+	 * reference.
+	 */
+	void ClearTailChunk(const struct music_chunk *chunk, bool *locked);
+};
+
+#endif
diff --git a/src/output/OutputAll.cxx b/src/output/OutputAll.cxx
deleted file mode 100644
index ded9fa1e1..000000000
--- a/src/output/OutputAll.cxx
+++ /dev/null
@@ -1,589 +0,0 @@
-/*
- * Copyright (C) 2003-2014 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 "config.h"
-#include "OutputAll.hxx"
-#include "PlayerControl.hxx"
-#include "OutputInternal.hxx"
-#include "OutputControl.hxx"
-#include "OutputError.hxx"
-#include "MusicBuffer.hxx"
-#include "MusicPipe.hxx"
-#include "MusicChunk.hxx"
-#include "system/FatalError.hxx"
-#include "util/Error.hxx"
-#include "config/ConfigData.hxx"
-#include "config/ConfigGlobal.hxx"
-#include "config/ConfigOption.hxx"
-#include "notify.hxx"
-
-#include <assert.h>
-#include <string.h>
-
-static AudioFormat input_audio_format;
-
-static struct audio_output **audio_outputs;
-static unsigned int num_audio_outputs;
-
-/**
- * The #MusicBuffer object where consumed chunks are returned.
- */
-static MusicBuffer *g_music_buffer;
-
-/**
- * The #MusicPipe object which feeds all audio outputs.  It is filled
- * by audio_output_all_play().
- */
-static MusicPipe *g_mp;
-
-/**
- * The "elapsed_time" stamp of the most recently finished chunk.
- */
-static float audio_output_all_elapsed_time = -1.0;
-
-unsigned int audio_output_count(void)
-{
-	return num_audio_outputs;
-}
-
-struct audio_output *
-audio_output_get(unsigned i)
-{
-	assert(i < num_audio_outputs);
-
-	assert(audio_outputs[i] != nullptr);
-
-	return audio_outputs[i];
-}
-
-struct audio_output *
-audio_output_find(const char *name)
-{
-	for (unsigned i = 0; i < num_audio_outputs; ++i) {
-		struct audio_output *ao = audio_output_get(i);
-
-		if (strcmp(ao->name, name) == 0)
-			return ao;
-	}
-
-	/* name not found */
-	return nullptr;
-}
-
-gcc_const
-static unsigned
-audio_output_config_count(void)
-{
-	unsigned int nr = 0;
-	const struct config_param *param = nullptr;
-
-	while ((param = config_get_next_param(CONF_AUDIO_OUTPUT, param)))
-		nr++;
-	if (!nr)
-		nr = 1; /* we'll always have at least one device  */
-	return nr;
-}
-
-void
-audio_output_all_init(PlayerControl &pc)
-{
-	const struct config_param *param = nullptr;
-	unsigned int i;
-	Error error;
-
-	num_audio_outputs = audio_output_config_count();
-	audio_outputs = new audio_output *[num_audio_outputs];
-
-	const config_param empty;
-
-	for (i = 0; i < num_audio_outputs; i++)
-	{
-		unsigned int j;
-
-		param = config_get_next_param(CONF_AUDIO_OUTPUT, param);
-		if (param == nullptr) {
-			/* only allow param to be nullptr if there
-			   just one audio output */
-			assert(i == 0);
-			assert(num_audio_outputs == 1);
-
-			param = &empty;
-		}
-
-		audio_output *output = audio_output_new(*param, pc, error);
-		if (output == nullptr) {
-			if (param != nullptr)
-				FormatFatalError("line %i: %s",
-						 param->line,
-						 error.GetMessage());
-			else
-				FatalError(error);
-		}
-
-		audio_outputs[i] = output;
-
-		/* require output names to be unique: */
-		for (j = 0; j < i; j++) {
-			if (!strcmp(output->name, audio_outputs[j]->name)) {
-				FormatFatalError("output devices with identical "
-						 "names: %s", output->name);
-			}
-		}
-	}
-}
-
-void
-audio_output_all_finish(void)
-{
-	unsigned int i;
-
-	for (i = 0; i < num_audio_outputs; i++) {
-		audio_output_disable(audio_outputs[i]);
-		audio_output_finish(audio_outputs[i]);
-	}
-
-	delete[] audio_outputs;
-	audio_outputs = nullptr;
-	num_audio_outputs = 0;
-}
-
-void
-audio_output_all_enable_disable(void)
-{
-	for (unsigned i = 0; i < num_audio_outputs; i++) {
-		struct audio_output *ao = audio_outputs[i];
-		bool enabled;
-
-		ao->mutex.lock();
-		enabled = ao->really_enabled;
-		ao->mutex.unlock();
-
-		if (ao->enabled != enabled) {
-			if (ao->enabled)
-				audio_output_enable(ao);
-			else
-				audio_output_disable(ao);
-		}
-	}
-}
-
-/**
- * Determine if all (active) outputs have finished the current
- * command.
- */
-static bool
-audio_output_all_finished(void)
-{
-	for (unsigned i = 0; i < num_audio_outputs; ++i) {
-		struct audio_output *ao = audio_outputs[i];
-
-		const ScopeLock protect(ao->mutex);
-		if (audio_output_is_open(ao) &&
-		    !audio_output_command_is_finished(ao))
-			return false;
-	}
-
-	return true;
-}
-
-static void audio_output_wait_all(void)
-{
-	while (!audio_output_all_finished())
-		audio_output_client_notify.Wait();
-}
-
-/**
- * Signals all audio outputs which are open.
- */
-static void
-audio_output_allow_play_all(void)
-{
-	for (unsigned i = 0; i < num_audio_outputs; ++i)
-		audio_output_allow_play(audio_outputs[i]);
-}
-
-static void
-audio_output_reset_reopen(struct audio_output *ao)
-{
-	const ScopeLock protect(ao->mutex);
-
-	ao->fail_timer.Reset();
-}
-
-/**
- * Resets the "reopen" flag on all audio devices.  MPD should
- * immediately retry to open the device instead of waiting for the
- * timeout when the user wants to start playback.
- */
-static void
-audio_output_all_reset_reopen(void)
-{
-	for (unsigned i = 0; i < num_audio_outputs; ++i) {
-		struct audio_output *ao = audio_outputs[i];
-
-		audio_output_reset_reopen(ao);
-	}
-}
-
-/**
- * Opens all output devices which are enabled, but closed.
- *
- * @return true if there is at least open output device which is open
- */
-static bool
-audio_output_all_update(void)
-{
-	unsigned int i;
-	bool ret = false;
-
-	if (!input_audio_format.IsDefined())
-		return false;
-
-	for (i = 0; i < num_audio_outputs; ++i)
-		ret = audio_output_update(audio_outputs[i],
-					  input_audio_format, *g_mp) || ret;
-
-	return ret;
-}
-
-void
-audio_output_all_set_replay_gain_mode(ReplayGainMode mode)
-{
-	for (unsigned i = 0; i < num_audio_outputs; ++i)
-		audio_output_set_replay_gain_mode(audio_outputs[i], mode);
-}
-
-bool
-audio_output_all_play(struct music_chunk *chunk, Error &error)
-{
-	bool ret;
-	unsigned int i;
-
-	assert(g_music_buffer != nullptr);
-	assert(g_mp != nullptr);
-	assert(chunk != nullptr);
-	assert(chunk->CheckFormat(input_audio_format));
-
-	ret = audio_output_all_update();
-	if (!ret) {
-		/* TODO: obtain real error */
-		error.Set(output_domain, "Failed to open audio output");
-		return false;
-	}
-
-	g_mp->Push(chunk);
-
-	for (i = 0; i < num_audio_outputs; ++i)
-		audio_output_play(audio_outputs[i]);
-
-	return true;
-}
-
-bool
-audio_output_all_open(const AudioFormat audio_format,
-		      MusicBuffer &buffer,
-		      Error &error)
-{
-	bool ret = false, enabled = false;
-	unsigned int i;
-
-	assert(g_music_buffer == nullptr || g_music_buffer == &buffer);
-	assert((g_mp == nullptr) == (g_music_buffer == nullptr));
-
-	g_music_buffer = &buffer;
-
-	/* the audio format must be the same as existing chunks in the
-	   pipe */
-	assert(g_mp == nullptr || g_mp->CheckFormat(audio_format));
-
-	if (g_mp == nullptr)
-		g_mp = new MusicPipe();
-	else
-		/* if the pipe hasn't been cleared, the the audio
-		   format must not have changed */
-		assert(g_mp->IsEmpty() || audio_format == input_audio_format);
-
-	input_audio_format = audio_format;
-
-	audio_output_all_reset_reopen();
-	audio_output_all_enable_disable();
-	audio_output_all_update();
-
-	for (i = 0; i < num_audio_outputs; ++i) {
-		if (audio_outputs[i]->enabled)
-			enabled = true;
-
-		if (audio_outputs[i]->open)
-			ret = true;
-	}
-
-	if (!enabled)
-		error.Set(output_domain, "All audio outputs are disabled");
-	else if (!ret)
-		/* TODO: obtain real error */
-		error.Set(output_domain, "Failed to open audio output");
-
-	if (!ret)
-		/* close all devices if there was an error */
-		audio_output_all_close();
-
-	return ret;
-}
-
-/**
- * Has the specified audio output already consumed this chunk?
- */
-static bool
-chunk_is_consumed_in(const struct audio_output *ao,
-		     const struct music_chunk *chunk)
-{
-	if (!ao->open)
-		return true;
-
-	if (ao->chunk == nullptr)
-		return false;
-
-	assert(chunk == ao->chunk || g_mp->Contains(ao->chunk));
-
-	if (chunk != ao->chunk) {
-		assert(chunk->next != nullptr);
-		return true;
-	}
-
-	return ao->chunk_finished && chunk->next == nullptr;
-}
-
-/**
- * Has this chunk been consumed by all audio outputs?
- */
-static bool
-chunk_is_consumed(const struct music_chunk *chunk)
-{
-	for (unsigned i = 0; i < num_audio_outputs; ++i) {
-		struct audio_output *ao = audio_outputs[i];
-
-		const ScopeLock protect(ao->mutex);
-		if (!chunk_is_consumed_in(ao, chunk))
-			return false;
-	}
-
-	return true;
-}
-
-/**
- * There's only one chunk left in the pipe (#g_mp), and all audio
- * outputs have consumed it already.  Clear the reference.
- */
-static void
-clear_tail_chunk(gcc_unused const struct music_chunk *chunk, bool *locked)
-{
-	assert(chunk->next == nullptr);
-	assert(g_mp->Contains(chunk));
-
-	for (unsigned i = 0; i < num_audio_outputs; ++i) {
-		struct audio_output *ao = audio_outputs[i];
-
-		/* this mutex will be unlocked by the caller when it's
-		   ready */
-		ao->mutex.lock();
-		locked[i] = ao->open;
-
-		if (!locked[i]) {
-			ao->mutex.unlock();
-			continue;
-		}
-
-		assert(ao->chunk == chunk);
-		assert(ao->chunk_finished);
-		ao->chunk = nullptr;
-	}
-}
-
-unsigned
-audio_output_all_check(void)
-{
-	const struct music_chunk *chunk;
-	bool is_tail;
-	struct music_chunk *shifted;
-	bool locked[num_audio_outputs];
-
-	assert(g_music_buffer != nullptr);
-	assert(g_mp != nullptr);
-
-	while ((chunk = g_mp->Peek()) != nullptr) {
-		assert(!g_mp->IsEmpty());
-
-		if (!chunk_is_consumed(chunk))
-			/* at least one output is not finished playing
-			   this chunk */
-			return g_mp->GetSize();
-
-		if (chunk->length > 0 && chunk->times >= 0.0)
-			/* only update elapsed_time if the chunk
-			   provides a defined value */
-			audio_output_all_elapsed_time = chunk->times;
-
-		is_tail = chunk->next == nullptr;
-		if (is_tail)
-			/* this is the tail of the pipe - clear the
-			   chunk reference in all outputs */
-			clear_tail_chunk(chunk, locked);
-
-		/* remove the chunk from the pipe */
-		shifted = g_mp->Shift();
-		assert(shifted == chunk);
-
-		if (is_tail)
-			/* unlock all audio outputs which were locked
-			   by clear_tail_chunk() */
-			for (unsigned i = 0; i < num_audio_outputs; ++i)
-				if (locked[i])
-					audio_outputs[i]->mutex.unlock();
-
-		/* return the chunk to the buffer */
-		g_music_buffer->Return(shifted);
-	}
-
-	return 0;
-}
-
-bool
-audio_output_all_wait(PlayerControl &pc, unsigned threshold)
-{
-	pc.Lock();
-
-	if (audio_output_all_check() < threshold) {
-		pc.Unlock();
-		return true;
-	}
-
-	pc.Wait();
-	pc.Unlock();
-
-	return audio_output_all_check() < threshold;
-}
-
-void
-audio_output_all_pause(void)
-{
-	unsigned int i;
-
-	audio_output_all_update();
-
-	for (i = 0; i < num_audio_outputs; ++i)
-		audio_output_pause(audio_outputs[i]);
-
-	audio_output_wait_all();
-}
-
-void
-audio_output_all_drain(void)
-{
-	for (unsigned i = 0; i < num_audio_outputs; ++i)
-		audio_output_drain_async(audio_outputs[i]);
-
-	audio_output_wait_all();
-}
-
-void
-audio_output_all_cancel(void)
-{
-	unsigned int i;
-
-	/* send the cancel() command to all audio outputs */
-
-	for (i = 0; i < num_audio_outputs; ++i)
-		audio_output_cancel(audio_outputs[i]);
-
-	audio_output_wait_all();
-
-	/* clear the music pipe and return all chunks to the buffer */
-
-	if (g_mp != nullptr)
-		g_mp->Clear(*g_music_buffer);
-
-	/* the audio outputs are now waiting for a signal, to
-	   synchronize the cleared music pipe */
-
-	audio_output_allow_play_all();
-
-	/* invalidate elapsed_time */
-
-	audio_output_all_elapsed_time = -1.0;
-}
-
-void
-audio_output_all_close(void)
-{
-	unsigned int i;
-
-	for (i = 0; i < num_audio_outputs; ++i)
-		audio_output_close(audio_outputs[i]);
-
-	if (g_mp != nullptr) {
-		assert(g_music_buffer != nullptr);
-
-		g_mp->Clear(*g_music_buffer);
-		delete g_mp;
-		g_mp = nullptr;
-	}
-
-	g_music_buffer = nullptr;
-
-	input_audio_format.Clear();
-
-	audio_output_all_elapsed_time = -1.0;
-}
-
-void
-audio_output_all_release(void)
-{
-	unsigned int i;
-
-	for (i = 0; i < num_audio_outputs; ++i)
-		audio_output_release(audio_outputs[i]);
-
-	if (g_mp != nullptr) {
-		assert(g_music_buffer != nullptr);
-
-		g_mp->Clear(*g_music_buffer);
-		delete g_mp;
-		g_mp = nullptr;
-	}
-
-	g_music_buffer = nullptr;
-
-	input_audio_format.Clear();
-
-	audio_output_all_elapsed_time = -1.0;
-}
-
-void
-audio_output_all_song_border(void)
-{
-	/* clear the elapsed_time pointer at the beginning of a new
-	   song */
-	audio_output_all_elapsed_time = 0.0;
-}
-
-float
-audio_output_all_get_elapsed_time(void)
-{
-	return audio_output_all_elapsed_time;
-}
diff --git a/src/output/OutputAll.hxx b/src/output/OutputAll.hxx
deleted file mode 100644
index b6166eb48..000000000
--- a/src/output/OutputAll.hxx
+++ /dev/null
@@ -1,174 +0,0 @@
-/*
- * Copyright (C) 2003-2014 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.
- */
-
-/*
- * Functions for dealing with all configured (enabled) audion outputs
- * at once.
- *
- */
-
-#ifndef OUTPUT_ALL_H
-#define OUTPUT_ALL_H
-
-#include "ReplayGainInfo.hxx"
-#include "Compiler.h"
-
-struct AudioFormat;
-class MusicBuffer;
-struct music_chunk;
-struct PlayerControl;
-class Error;
-
-/**
- * Global initialization: load audio outputs from the configuration
- * file and initialize them.
- */
-void
-audio_output_all_init(PlayerControl &pc);
-
-/**
- * Global finalization: free memory occupied by audio outputs.  All
- */
-void
-audio_output_all_finish(void);
-
-/**
- * Returns the total number of audio output devices, including those
- * who are disabled right now.
- */
-gcc_const
-unsigned int audio_output_count(void);
-
-/**
- * Returns the "i"th audio output device.
- */
-gcc_const
-struct audio_output *
-audio_output_get(unsigned i);
-
-/**
- * Returns the audio output device with the specified name.  Returns
- * NULL if the name does not exist.
- */
-gcc_pure
-struct audio_output *
-audio_output_find(const char *name);
-
-/**
- * Checks the "enabled" flag of all audio outputs, and if one has
- * changed, commit the change.
- */
-void
-audio_output_all_enable_disable(void);
-
-/**
- * Opens all audio outputs which are not disabled.
- *
- * @param audio_format the preferred audio format
- * @param buffer the #music_buffer where consumed #music_chunk objects
- * should be returned
- * @return true on success, false on failure
- */
-bool
-audio_output_all_open(AudioFormat audio_format,
-		      MusicBuffer &buffer,
-		      Error &error);
-
-/**
- * Closes all audio outputs.
- */
-void
-audio_output_all_close(void);
-
-/**
- * Closes all audio outputs.  Outputs with the "always_on" flag are
- * put into pause mode.
- */
-void
-audio_output_all_release(void);
-
-void
-audio_output_all_set_replay_gain_mode(ReplayGainMode mode);
-
-/**
- * Enqueue a #music_chunk object for playing, i.e. pushes it to a
- * #MusicPipe.
- *
- * @param chunk the #music_chunk object to be played
- * @return true on success, false if no audio output was able to play
- * (all closed then)
- */
-bool
-audio_output_all_play(music_chunk *chunk, Error &error);
-
-/**
- * Checks if the output devices have drained their music pipe, and
- * returns the consumed music chunks to the #music_buffer.
- *
- * @return the number of chunks to play left in the #MusicPipe
- */
-unsigned
-audio_output_all_check(void);
-
-/**
- * Checks if the size of the #MusicPipe is below the #threshold.  If
- * not, it attempts to synchronize with all output threads, and waits
- * until another #music_chunk is finished.
- *
- * @param threshold the maximum number of chunks in the pipe
- * @return true if there are less than #threshold chunks in the pipe
- */
-bool
-audio_output_all_wait(PlayerControl &pc, unsigned threshold);
-
-/**
- * Puts all audio outputs into pause mode.  Most implementations will
- * simply close it then.
- */
-void
-audio_output_all_pause(void);
-
-/**
- * Drain all audio outputs.
- */
-void
-audio_output_all_drain(void);
-
-/**
- * Try to cancel data which may still be in the device's buffers.
- */
-void
-audio_output_all_cancel(void);
-
-/**
- * Indicate that a new song will begin now.
- */
-void
-audio_output_all_song_border(void);
-
-/**
- * Returns the "elapsed_time" stamp of the most recently finished
- * chunk.  A negative value is returned when no chunk has been
- * finished yet.
- */
-gcc_pure
-float
-audio_output_all_get_elapsed_time(void);
-
-#endif
diff --git a/src/output/OutputCommand.cxx b/src/output/OutputCommand.cxx
index d82b7c696..d4c1d844d 100644
--- a/src/output/OutputCommand.cxx
+++ b/src/output/OutputCommand.cxx
@@ -26,7 +26,7 @@
 
 #include "config.h"
 #include "OutputCommand.hxx"
-#include "OutputAll.hxx"
+#include "MultipleOutputs.hxx"
 #include "OutputInternal.hxx"
 #include "PlayerControl.hxx"
 #include "mixer/MixerControl.hxx"
@@ -35,21 +35,19 @@
 extern unsigned audio_output_state_version;
 
 bool
-audio_output_enable_index(unsigned idx)
+audio_output_enable_index(MultipleOutputs &outputs, unsigned idx)
 {
-	struct audio_output *ao;
-
-	if (idx >= audio_output_count())
+	if (idx >= outputs.Size())
 		return false;
 
-	ao = audio_output_get(idx);
-	if (ao->enabled)
+	audio_output &ao = outputs.Get(idx);
+	if (ao.enabled)
 		return true;
 
-	ao->enabled = true;
+	ao.enabled = true;
 	idle_add(IDLE_OUTPUT);
 
-	ao->player_control->UpdateAudio();
+	ao.player_control->UpdateAudio();
 
 	++audio_output_state_version;
 
@@ -57,27 +55,25 @@ audio_output_enable_index(unsigned idx)
 }
 
 bool
-audio_output_disable_index(unsigned idx)
+audio_output_disable_index(MultipleOutputs &outputs, unsigned idx)
 {
-	struct audio_output *ao;
-
-	if (idx >= audio_output_count())
+	if (idx >= outputs.Size())
 		return false;
 
-	ao = audio_output_get(idx);
-	if (!ao->enabled)
+	audio_output &ao = outputs.Get(idx);
+	if (!ao.enabled)
 		return true;
 
-	ao->enabled = false;
+	ao.enabled = false;
 	idle_add(IDLE_OUTPUT);
 
-	Mixer *mixer = ao->mixer;
+	Mixer *mixer = ao.mixer;
 	if (mixer != nullptr) {
 		mixer_close(mixer);
 		idle_add(IDLE_MIXER);
 	}
 
-	ao->player_control->UpdateAudio();
+	ao.player_control->UpdateAudio();
 
 	++audio_output_state_version;
 
@@ -85,26 +81,24 @@ audio_output_disable_index(unsigned idx)
 }
 
 bool
-audio_output_toggle_index(unsigned idx)
+audio_output_toggle_index(MultipleOutputs &outputs, unsigned idx)
 {
-	struct audio_output *ao;
-
-	if (idx >= audio_output_count())
+	if (idx >= outputs.Size())
 		return false;
 
-	ao = audio_output_get(idx);
-	const bool enabled = ao->enabled = !ao->enabled;
+	audio_output &ao = outputs.Get(idx);
+	const bool enabled = ao.enabled = !ao.enabled;
 	idle_add(IDLE_OUTPUT);
 
 	if (!enabled) {
-		Mixer *mixer = ao->mixer;
+		Mixer *mixer = ao.mixer;
 		if (mixer != nullptr) {
 			mixer_close(mixer);
 			idle_add(IDLE_MIXER);
 		}
 	}
 
-	ao->player_control->UpdateAudio();
+	ao.player_control->UpdateAudio();
 
 	++audio_output_state_version;
 
diff --git a/src/output/OutputCommand.hxx b/src/output/OutputCommand.hxx
index 4c44dff53..53fc5c95e 100644
--- a/src/output/OutputCommand.hxx
+++ b/src/output/OutputCommand.hxx
@@ -27,25 +27,27 @@
 #ifndef MPD_OUTPUT_COMMAND_HXX
 #define MPD_OUTPUT_COMMAND_HXX
 
+class MultipleOutputs;
+
 /**
  * Enables an audio output.  Returns false if the specified output
  * does not exist.
  */
 bool
-audio_output_enable_index(unsigned idx);
+audio_output_enable_index(MultipleOutputs &outputs, unsigned idx);
 
 /**
  * Disables an audio output.  Returns false if the specified output
  * does not exist.
  */
 bool
-audio_output_disable_index(unsigned idx);
+audio_output_disable_index(MultipleOutputs &outputs, unsigned idx);
 
 /**
  * Toggles an audio output.  Returns false if the specified output
  * does not exist.
  */
 bool
-audio_output_toggle_index(unsigned idx);
+audio_output_toggle_index(MultipleOutputs &outputs, unsigned idx);
 
 #endif
diff --git a/src/output/OutputPrint.cxx b/src/output/OutputPrint.cxx
index 66826f140..7e0536bf5 100644
--- a/src/output/OutputPrint.cxx
+++ b/src/output/OutputPrint.cxx
@@ -24,22 +24,20 @@
 
 #include "config.h"
 #include "OutputPrint.hxx"
-#include "OutputAll.hxx"
+#include "MultipleOutputs.hxx"
 #include "OutputInternal.hxx"
 #include "client/Client.hxx"
 
 void
-printAudioDevices(Client &client)
+printAudioDevices(Client &client, const MultipleOutputs &outputs)
 {
-	const unsigned n = audio_output_count();
-
-	for (unsigned i = 0; i < n; ++i) {
-		const struct audio_output *ao = audio_output_get(i);
+	for (unsigned i = 0, n = outputs.Size(); i != n; ++i) {
+		const audio_output &ao = outputs.Get(i);
 
 		client_printf(client,
 			      "outputid: %i\n"
 			      "outputname: %s\n"
 			      "outputenabled: %i\n",
-			      i, ao->name, ao->enabled);
+			      i, ao.name, ao.enabled);
 	}
 }
diff --git a/src/output/OutputPrint.hxx b/src/output/OutputPrint.hxx
index 2d94226fd..29aa2b11c 100644
--- a/src/output/OutputPrint.hxx
+++ b/src/output/OutputPrint.hxx
@@ -1,4 +1,3 @@
-
 /*
  * Copyright (C) 2003-2014 The Music Player Daemon Project
  * http://www.musicpd.org
@@ -27,8 +26,9 @@
 #define MPD_OUTPUT_PRINT_HXX
 
 class Client;
+class MultipleOutputs;
 
 void
-printAudioDevices(Client &client);
+printAudioDevices(Client &client, const MultipleOutputs &outputs);
 
 #endif
diff --git a/src/output/OutputState.cxx b/src/output/OutputState.cxx
index 1141abeda..abd5dd2ae 100644
--- a/src/output/OutputState.cxx
+++ b/src/output/OutputState.cxx
@@ -24,7 +24,7 @@
 
 #include "config.h"
 #include "OutputState.hxx"
-#include "OutputAll.hxx"
+#include "MultipleOutputs.hxx"
 #include "OutputInternal.hxx"
 #include "OutputError.hxx"
 #include "Log.hxx"
@@ -38,27 +38,22 @@
 unsigned audio_output_state_version;
 
 void
-audio_output_state_save(FILE *fp)
+audio_output_state_save(FILE *fp, const MultipleOutputs &outputs)
 {
-	unsigned n = audio_output_count();
-
-	assert(n > 0);
-
-	for (unsigned i = 0; i < n; ++i) {
-		const struct audio_output *ao = audio_output_get(i);
+	for (unsigned i = 0, n = outputs.Size(); i != n; ++i) {
+		const audio_output &ao = outputs.Get(i);
 
 		fprintf(fp, AUDIO_DEVICE_STATE "%d:%s\n",
-			ao->enabled, ao->name);
+			ao.enabled, ao.name);
 	}
 }
 
 bool
-audio_output_state_read(const char *line)
+audio_output_state_read(const char *line, MultipleOutputs &outputs)
 {
 	long value;
 	char *endptr;
 	const char *name;
-	struct audio_output *ao;
 
 	if (!StringStartsWith(line, AUDIO_DEVICE_STATE))
 		return false;
@@ -74,7 +69,7 @@ audio_output_state_read(const char *line)
 		return true;
 
 	name = endptr + 1;
-	ao = audio_output_find(name);
+	audio_output *ao = outputs.FindByName(name);
 	if (ao == NULL) {
 		FormatDebug(output_domain,
 			    "Ignoring device state for '%s'", name);
diff --git a/src/output/OutputState.hxx b/src/output/OutputState.hxx
index a68180ae4..32f4bbcce 100644
--- a/src/output/OutputState.hxx
+++ b/src/output/OutputState.hxx
@@ -27,11 +27,13 @@
 
 #include <stdio.h>
 
+class MultipleOutputs;
+
 bool
-audio_output_state_read(const char *line);
+audio_output_state_read(const char *line, MultipleOutputs &outputs);
 
 void
-audio_output_state_save(FILE *fp);
+audio_output_state_save(FILE *fp, const MultipleOutputs &outputs);
 
 /**
  * Generates a version number for the current state of the audio