output_*: convert to C++

src/OutputControl.cxx

@@ -0,0 +1,340 @@
+/*
+ * Copyright (C) 2003-2013 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 "OutputControl.hxx"
+#include "OutputThread.hxx"
+
+extern "C" {
+#include "output_api.h"
+#include "output_internal.h"
+#include "mixer_control.h"
+#include "mixer_plugin.h"
+#include "notify.h"
+}
+
+#include "filter_plugin.h"
+
+#include <assert.h>
+#include <stdlib.h>
+
+enum {
+	/** after a failure, wait this number of seconds before
+	    automatically reopening the device */
+	REOPEN_AFTER = 10,
+};
+
+struct notify audio_output_client_notify;
+
+/**
+ * Waits for command completion.
+ *
+ * @param ao the #audio_output instance; must be locked
+ */
+static void ao_command_wait(struct audio_output *ao)
+{
+	while (ao->command != AO_COMMAND_NONE) {
+		g_mutex_unlock(ao->mutex);
+		notify_wait(&audio_output_client_notify);
+		g_mutex_lock(ao->mutex);
+	}
+}
+
+/**
+ * Sends a command to the #audio_output object, but does not wait for
+ * completion.
+ *
+ * @param ao the #audio_output instance; must be locked
+ */
+static void ao_command_async(struct audio_output *ao,
+			     enum audio_output_command cmd)
+{
+	assert(ao->command == AO_COMMAND_NONE);
+	ao->command = cmd;
+	g_cond_signal(ao->cond);
+}
+
+/**
+ * Sends a command to the #audio_output object and waits for
+ * completion.
+ *
+ * @param ao the #audio_output instance; must be locked
+ */
+static void
+ao_command(struct audio_output *ao, enum audio_output_command cmd)
+{
+	ao_command_async(ao, cmd);
+	ao_command_wait(ao);
+}
+
+/**
+ * Lock the #audio_output object and execute the command
+ * synchronously.
+ */
+static void
+ao_lock_command(struct audio_output *ao, enum audio_output_command cmd)
+{
+	g_mutex_lock(ao->mutex);
+	ao_command(ao, cmd);
+	g_mutex_unlock(ao->mutex);
+}
+
+void
+audio_output_enable(struct audio_output *ao)
+{
+	if (ao->thread == NULL) {
+		if (ao->plugin->enable == NULL) {
+			/* don't bother to start the thread now if the
+			   device doesn't even have a enable() method;
+			   just assign the variable and we're done */
+			ao->really_enabled = true;
+			return;
+		}
+
+		audio_output_thread_start(ao);
+	}
+
+	ao_lock_command(ao, AO_COMMAND_ENABLE);
+}
+
+void
+audio_output_disable(struct audio_output *ao)
+{
+	if (ao->thread == NULL) {
+		if (ao->plugin->disable == NULL)
+			ao->really_enabled = false;
+		else
+			/* if there's no thread yet, the device cannot
+			   be enabled */
+			assert(!ao->really_enabled);
+
+		return;
+	}
+
+	ao_lock_command(ao, AO_COMMAND_DISABLE);
+}
+
+/**
+ * Object must be locked (and unlocked) by the caller.
+ */
+static bool
+audio_output_open(struct audio_output *ao,
+		  const struct audio_format *audio_format,
+		  const struct music_pipe *mp)
+{
+	bool open;
+
+	assert(ao != NULL);
+	assert(ao->allow_play);
+	assert(audio_format_valid(audio_format));
+	assert(mp != NULL);
+
+	if (ao->fail_timer != NULL) {
+		g_timer_destroy(ao->fail_timer);
+		ao->fail_timer = NULL;
+	}
+
+	if (ao->open &&
+	    audio_format_equals(audio_format, &ao->in_audio_format)) {
+		assert(ao->pipe == mp ||
+		       (ao->always_on && ao->pause));
+
+		if (ao->pause) {
+			ao->chunk = NULL;
+			ao->pipe = mp;
+
+			/* unpause with the CANCEL command; this is a
+			   hack, but suits well for forcing the thread
+			   to leave the ao_pause() thread, and we need
+			   to flush the device buffer anyway */
+
+			/* we're not using audio_output_cancel() here,
+			   because that function is asynchronous */
+			ao_command(ao, AO_COMMAND_CANCEL);
+		}
+
+		return true;
+	}
+
+	ao->in_audio_format = *audio_format;
+	ao->chunk = NULL;
+
+	ao->pipe = mp;
+
+	if (ao->thread == NULL)
+		audio_output_thread_start(ao);
+
+	ao_command(ao, ao->open ? AO_COMMAND_REOPEN : AO_COMMAND_OPEN);
+	open = ao->open;
+
+	if (open && ao->mixer != NULL) {
+		GError *error = NULL;
+
+		if (!mixer_open(ao->mixer, &error)) {
+			g_warning("Failed to open mixer for '%s': %s",
+				  ao->name, error->message);
+			g_error_free(error);
+		}
+	}
+
+	return open;
+}
+
+/**
+ * Same as audio_output_close(), but expects the lock to be held by
+ * the caller.
+ */
+static void
+audio_output_close_locked(struct audio_output *ao)
+{
+	assert(ao != NULL);
+	assert(ao->allow_play);
+
+	if (ao->mixer != NULL)
+		mixer_auto_close(ao->mixer);
+
+	assert(!ao->open || ao->fail_timer == NULL);
+
+	if (ao->open)
+		ao_command(ao, AO_COMMAND_CLOSE);
+	else if (ao->fail_timer != NULL) {
+		g_timer_destroy(ao->fail_timer);
+		ao->fail_timer = NULL;
+	}
+}
+
+bool
+audio_output_update(struct audio_output *ao,
+		    const struct audio_format *audio_format,
+		    const struct music_pipe *mp)
+{
+	assert(mp != NULL);
+
+	g_mutex_lock(ao->mutex);
+
+	if (ao->enabled && ao->really_enabled) {
+		if (ao->fail_timer == NULL ||
+		    g_timer_elapsed(ao->fail_timer, NULL) > REOPEN_AFTER) {
+			bool success = audio_output_open(ao, audio_format, mp);
+			g_mutex_unlock(ao->mutex);
+			return success;
+		}
+	} else if (audio_output_is_open(ao))
+		audio_output_close_locked(ao);
+
+	g_mutex_unlock(ao->mutex);
+	return false;
+}
+
+void
+audio_output_play(struct audio_output *ao)
+{
+	g_mutex_lock(ao->mutex);
+
+	assert(ao->allow_play);
+
+	if (audio_output_is_open(ao))
+		g_cond_signal(ao->cond);
+
+	g_mutex_unlock(ao->mutex);
+}
+
+void audio_output_pause(struct audio_output *ao)
+{
+	if (ao->mixer != NULL && ao->plugin->pause == NULL)
+		/* the device has no pause mode: close the mixer,
+		   unless its "global" flag is set (checked by
+		   mixer_auto_close()) */
+		mixer_auto_close(ao->mixer);
+
+	g_mutex_lock(ao->mutex);
+	assert(ao->allow_play);
+	if (audio_output_is_open(ao))
+		ao_command_async(ao, AO_COMMAND_PAUSE);
+	g_mutex_unlock(ao->mutex);
+}
+
+void
+audio_output_drain_async(struct audio_output *ao)
+{
+	g_mutex_lock(ao->mutex);
+	assert(ao->allow_play);
+	if (audio_output_is_open(ao))
+		ao_command_async(ao, AO_COMMAND_DRAIN);
+	g_mutex_unlock(ao->mutex);
+}
+
+void audio_output_cancel(struct audio_output *ao)
+{
+	g_mutex_lock(ao->mutex);
+
+	if (audio_output_is_open(ao)) {
+		ao->allow_play = false;
+		ao_command_async(ao, AO_COMMAND_CANCEL);
+	}
+
+	g_mutex_unlock(ao->mutex);
+}
+
+void
+audio_output_allow_play(struct audio_output *ao)
+{
+	g_mutex_lock(ao->mutex);
+
+	ao->allow_play = true;
+	if (audio_output_is_open(ao))
+		g_cond_signal(ao->cond);
+
+	g_mutex_unlock(ao->mutex);
+}
+
+void
+audio_output_release(struct audio_output *ao)
+{
+	if (ao->always_on)
+		audio_output_pause(ao);
+	else
+		audio_output_close(ao);
+}
+
+void audio_output_close(struct audio_output *ao)
+{
+	assert(ao != NULL);
+	assert(!ao->open || ao->fail_timer == NULL);
+
+	g_mutex_lock(ao->mutex);
+	audio_output_close_locked(ao);
+	g_mutex_unlock(ao->mutex);
+}
+
+void audio_output_finish(struct audio_output *ao)
+{
+	audio_output_close(ao);
+
+	assert(ao->fail_timer == NULL);
+
+	if (ao->thread != NULL) {
+		assert(ao->allow_play);
+		ao_lock_command(ao, AO_COMMAND_KILL);
+		g_thread_join(ao->thread);
+		ao->thread = NULL;
+	}
+
+	audio_output_free(ao);
+}