input_stream: non-blocking I/O

Add GMutex, GCond attributes which will be used by callers to
conditionally wait on the stream.

Remove the (now-useless) plugin method buffer(), wait on GCond
instead.  Lock the input_stream before each method call.  Do the same
with the playlist plugins.

test/dump_playlist.c

@@ -92,11 +92,14 @@ int main(int argc, char **argv)
 
 	/* open the playlist */
 
-	playlist = playlist_list_open_uri(uri);
+	GMutex *mutex = g_mutex_new();
+	GCond *cond = g_cond_new();
+
+	playlist = playlist_list_open_uri(uri, mutex, cond);
 	if (playlist == NULL) {
 		/* open the stream and wait until it becomes ready */
 
-		is = input_stream_open(uri, &error);
+		is = input_stream_open(uri, mutex, cond, &error);
 		if (is == NULL) {
 			if (error != NULL) {
 				g_warning("%s", error->message);
@@ -106,19 +109,7 @@ int main(int argc, char **argv)
 			return 2;
 		}
 
-		while (!is->ready) {
-			int ret = input_stream_buffer(is, &error);
-			if (ret < 0) {
-				/* error */
-				g_warning("%s", error->message);
-				g_error_free(error);
-				return 2;
-			}
-
-			if (ret == 0)
-				/* nothing was buffered - wait */
-				g_usleep(10000);
-		}
+		input_stream_lock_wait_ready(is);
 
 		/* open the playlist */
 
@@ -157,6 +148,10 @@ int main(int argc, char **argv)
 	playlist_plugin_close(playlist);
 	if (is != NULL)
 		input_stream_close(is);
+
+	g_cond_free(cond);
+	g_mutex_free(mutex);
+
 	playlist_list_global_finish();
 	input_stream_global_finish();
 	io_thread_deinit();

test/read_tags.c

@@ -91,7 +91,7 @@ decoder_read(G_GNUC_UNUSED struct decoder *decoder,
 	     struct input_stream *is,
 	     void *buffer, size_t length)
 {
-	return input_stream_read(is, buffer, length, NULL);
+	return input_stream_lock_read(is, buffer, length, NULL);
 }
 
 void
@@ -193,7 +193,11 @@ int main(int argc, char **argv)
 
 	tag = decoder_plugin_tag_dup(plugin, path);
 	if (tag == NULL && plugin->stream_tag != NULL) {
-		struct input_stream *is = input_stream_open(path, &error);
+		GMutex *mutex = g_mutex_new();
+		GCond *cond = g_cond_new();
+
+		struct input_stream *is =
+			input_stream_open(path, mutex, cond, &error);
 
 		if (is == NULL) {
 			g_printerr("Failed to open %s: %s\n",
@@ -204,6 +208,9 @@ int main(int argc, char **argv)
 
 		tag = decoder_plugin_stream_tag(plugin, is);
 		input_stream_close(is);
+
+		g_cond_free(cond);
+		g_mutex_free(mutex);
 	}
 
 	decoder_plugin_deinit_all();

test/run_decoder.c

@@ -112,7 +112,7 @@ decoder_read(G_GNUC_UNUSED struct decoder *decoder,
 	     struct input_stream *is,
 	     void *buffer, size_t length)
 {
-	return input_stream_read(is, buffer, length, NULL);
+	return input_stream_lock_read(is, buffer, length, NULL);
 }
 
 void
@@ -209,8 +209,11 @@ int main(int argc, char **argv)
 		decoder_plugin_file_decode(decoder.plugin, &decoder,
 					   decoder.uri);
 	} else if (decoder.plugin->stream_decode != NULL) {
+		GMutex *mutex = g_mutex_new();
+		GCond *cond = g_cond_new();
+
 		struct input_stream *is =
-			input_stream_open(decoder.uri, &error);
+			input_stream_open(decoder.uri, mutex, cond, &error);
 		if (is == NULL) {
 			if (error != NULL) {
 				g_warning("%s", error->message);
@@ -224,6 +227,9 @@ int main(int argc, char **argv)
 		decoder_plugin_stream_decode(decoder.plugin, &decoder, is);
 
 		input_stream_close(is);
+
+		g_cond_free(cond);
+		g_mutex_free(mutex);
 	} else {
 		g_printerr("Decoder plugin is not usable\n");
 		return 1;

test/run_input.c

@@ -53,20 +53,17 @@ dump_input_stream(struct input_stream *is)
 	size_t num_read;
 	ssize_t num_written;
 
+	g_mutex_lock(is->mutex);
+
 	/* wait until the stream becomes ready */
 
-	while (!is->ready) {
-		int ret = input_stream_buffer(is, &error);
-		if (ret < 0) {
-			/* error */
-			g_warning("%s", error->message);
-			g_error_free(error);
-			return 2;
-		}
+	input_stream_wait_ready(is);
 
-		if (ret == 0)
-			/* nothing was buffered - wait */
-			g_usleep(10000);
+	if (!input_stream_check(is, &error)) {
+		g_warning("%s", error->message);
+		g_error_free(error);
+		g_mutex_unlock(is->mutex);
+		return EXIT_FAILURE;
 	}
 
 	/* print meta data */
@@ -103,9 +100,12 @@ dump_input_stream(struct input_stream *is)
 	if (!input_stream_check(is, &error)) {
 		g_warning("%s", error->message);
 		g_error_free(error);
+		g_mutex_unlock(is->mutex);
 		return EXIT_FAILURE;
 	}
 
+	g_mutex_unlock(is->mutex);
+
 	return 0;
 }
 
@@ -149,7 +149,10 @@ int main(int argc, char **argv)
 
 	/* open the stream and dump it */
 
-	is = input_stream_open(argv[1], &error);
+	GMutex *mutex = g_mutex_new();
+	GCond *cond = g_cond_new();
+
+	is = input_stream_open(argv[1], mutex, cond, &error);
 	if (is != NULL) {
 		ret = dump_input_stream(is);
 		input_stream_close(is);
@@ -162,6 +165,9 @@ int main(int argc, char **argv)
 		ret = 2;
 	}
 
+	g_cond_free(cond);
+	g_mutex_free(mutex);
+
 	/* deinitialize everything */
 
 	input_stream_global_finish();