output_api: moved the command check out of method pause()

Move the "while" loop which checks for commands to the caller
ao_pause().  This simplifies the pause() method, and lets us remove
audio_output_is_pending().

src/output/shout_plugin.c

@@ -506,19 +506,12 @@ my_shout_play(void *data, const char *chunk, size_t size)
 	return true;
 }
 
-static void my_shout_pause(void *data)
+static bool
+my_shout_pause(void *data)
 {
-	struct shout_data *sd = (struct shout_data *)data;
 	static const char silence[1020];
-	int ret;
 
-	/* play silence until the player thread sends us a command */
-
-	while (sd->opened && !audio_output_is_pending(sd->audio_output)) {
-		ret = my_shout_play(data, silence, sizeof(silence));
-		if (ret != 0)
-			break;
-	}
+	return my_shout_play(data, silence, sizeof(silence));
 }
 
 static void my_shout_set_tag(void *data,

src/output_api.c

@@ -19,14 +19,7 @@
 #include "output_api.h"
 #include "output_internal.h"
 
-#include <assert.h>
-
 const char *audio_output_get_name(const struct audio_output *ao)
 {
 	return ao->name;
 }
-
-bool audio_output_is_pending(const struct audio_output *ao)
-{
-	return ao->command != AO_COMMAND_NONE;
-}

src/output_api.h

@@ -84,8 +84,11 @@ struct audio_output_plugin {
 	 * silence during pause, so their clients won't be
 	 * disconnected.  Plugins which do not support pausing will
 	 * simply be closed, and have to be reopened when unpaused.
+	 *
+	 * @return false on error (output will be closed then), true
+	 * for continue to pause
 	 */
-	void (*pause)(void *data);
+	bool (*pause)(void *data);
 
 	/**
 	 * Try to cancel data which may still be in the device's
@@ -131,9 +134,4 @@ struct audio_output;
 
 const char *audio_output_get_name(const struct audio_output *ao);
 
-/**
- * Returns true if there is a command pending.
- */
-bool audio_output_is_pending(const struct audio_output *ao);
-
 #endif

src/output_thread.c

@@ -77,7 +77,17 @@ static void ao_pause(struct audio_output *ao)
 	if (ao->plugin->pause != NULL) {
 		/* pause is supported */
 		ao_command_finished(ao);
-		ao->plugin->pause(ao->data);
+
+		do {
+			bool ret;
+
+			ret = ao->plugin->pause(ao->data);
+			if (!ret) {
+				ao->plugin->close(ao->data);
+				pcm_convert_deinit(&ao->convState);
+				ao->open = false;
+			}
+		} while (ao->command == AO_COMMAND_NONE);
 	} else {
 		/* pause is not supported - simply close the device */
 		ao->plugin->close(ao->data);