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.

src/input/archive_input_plugin.c

@@ -34,7 +34,9 @@
  * plugin and gzip fetches file from disk
  */
 static struct input_stream *
-input_archive_open(const char *pathname, GError **error_r)
+input_archive_open(const char *pathname,
+		   GMutex *mutex, GCond *cond,
+		   GError **error_r)
 {
 	const struct archive_plugin *arplug;
 	struct archive_file *file;
@@ -65,7 +67,8 @@ input_archive_open(const char *pathname, GError **error_r)
 		return NULL;
 
 	//setup fileops
-	is = archive_file_open_stream(file, filename, error_r);
+	is = archive_file_open_stream(file, filename, mutex, cond,
+				      error_r);
 	archive_file_close(file);
 	g_free(pname);
 

src/input/cdio_paranoia_input_plugin.c

@@ -149,7 +149,9 @@ cdio_detect_device(void)
 }
 
 static struct input_stream *
-input_cdio_open(const char *uri, GError **error_r)
+input_cdio_open(const char *uri,
+		GMutex *mutex, GCond *cond,
+		GError **error_r)
 {
 	struct input_cdio_paranoia *i;
 
@@ -158,7 +160,8 @@ input_cdio_open(const char *uri, GError **error_r)
 		return NULL;
 
 	i = g_new(struct input_cdio_paranoia, 1);
-	input_stream_init(&i->base, &input_plugin_cdio_paranoia, uri);
+	input_stream_init(&i->base, &input_plugin_cdio_paranoia, uri,
+			  mutex, cond);
 
 	/* initialize everything (should be already) */
 	i->drv = NULL;

src/input/curl_input_plugin.c

@@ -81,9 +81,6 @@ struct input_curl {
 	/** the curl handles */
 	CURL *easy;
 
-	GMutex *mutex;
-	GCond *cond;
-
 	/** the GMainLoop source used to poll all CURL file
 	    descriptors */
 	GSource *source;
@@ -433,11 +430,11 @@ input_curl_abort_all_requests(GError *error)
 
 		input_curl_easy_free(c);
 
-		g_mutex_lock(c->mutex);
+		g_mutex_lock(c->base.mutex);
 		c->postponed_error = g_error_copy(error);
 		c->base.ready = true;
-		g_cond_broadcast(c->cond);
-		g_mutex_unlock(c->mutex);
+		g_cond_broadcast(c->base.cond);
+		g_mutex_unlock(c->base.mutex);
 	}
 
 	g_error_free(error);
@@ -457,7 +454,7 @@ input_curl_request_done(struct input_curl *c, CURLcode result, long status)
 	assert(c->easy == NULL);
 	assert(c->postponed_error == NULL);
 
-	g_mutex_lock(c->mutex);
+	g_mutex_lock(c->base.mutex);
 
 	if (result != CURLE_OK) {
 		c->postponed_error = g_error_new(curl_quark(), result,
@@ -470,8 +467,8 @@ input_curl_request_done(struct input_curl *c, CURLcode result, long status)
 	}
 
 	c->base.ready = true;
-	g_cond_broadcast(c->cond);
-	g_mutex_unlock(c->mutex);
+	g_cond_broadcast(c->base.cond);
+	g_mutex_unlock(c->base.mutex);
 }
 
 static void
@@ -763,9 +760,6 @@ input_curl_free(struct input_curl *c)
 
 	g_queue_free(c->buffers);
 
-	g_mutex_free(c->mutex);
-	g_cond_free(c->cond);
-
 	if (c->postponed_error != NULL)
 		g_error_free(c->postponed_error);
 
@@ -779,15 +773,12 @@ input_curl_check(struct input_stream *is, GError **error_r)
 {
 	struct input_curl *c = (struct input_curl *)is;
 
-	g_mutex_lock(c->mutex);
-
 	bool success = c->postponed_error == NULL;
 	if (!success) {
 		g_propagate_error(error_r, c->postponed_error);
 		c->postponed_error = NULL;
 	}
 
-	g_mutex_unlock(c->mutex);
 	return success;
 }
 
@@ -805,7 +796,7 @@ static bool
 fill_buffer(struct input_curl *c, GError **error_r)
 {
 	while (c->easy != NULL && g_queue_is_empty(c->buffers))
-		g_cond_wait(c->cond, c->mutex);
+		g_cond_wait(c->base.cond, c->base.mutex);
 
 	if (c->postponed_error != NULL) {
 		g_propagate_error(error_r, c->postponed_error);
@@ -906,6 +897,15 @@ copy_icy_tag(struct input_curl *c)
 	c->tag = tag;
 }
 
+static bool
+input_curl_available(struct input_stream *is)
+{
+	struct input_curl *c = (struct input_curl *)is;
+
+	return c->postponed_error != NULL || c->easy == NULL ||
+		!g_queue_is_empty(c->buffers);
+}
+
 static size_t
 input_curl_read(struct input_stream *is, void *ptr, size_t size,
 		GError **error_r)
@@ -915,16 +915,12 @@ input_curl_read(struct input_stream *is, void *ptr, size_t size,
 	size_t nbytes = 0;
 	char *dest = ptr;
 
-	g_mutex_lock(c->mutex);
-
 	do {
 		/* fill the buffer */
 
 		success = fill_buffer(c, error_r);
-		if (!success) {
-			g_mutex_unlock(c->mutex);
+		if (!success)
 			return 0;
-		}
 
 		/* send buffer contents */
 
@@ -944,14 +940,12 @@ input_curl_read(struct input_stream *is, void *ptr, size_t size,
 
 #if LIBCURL_VERSION_NUM >= 0x071200
 	if (c->paused && curl_total_buffer_size(c) < CURL_RESUME_AT) {
-		g_mutex_unlock(c->mutex);
+		g_mutex_unlock(c->base.mutex);
 		io_thread_call(input_curl_resume, c);
-		g_mutex_lock(c->mutex);
+		g_mutex_lock(c->base.mutex);
 	}
 #endif
 
-	g_mutex_unlock(c->mutex);
-
 	return nbytes;
 }
 
@@ -968,33 +962,7 @@ input_curl_eof(G_GNUC_UNUSED struct input_stream *is)
 {
 	struct input_curl *c = (struct input_curl *)is;
 
-	g_mutex_lock(c->mutex);
-	bool eof = c->easy == NULL && g_queue_is_empty(c->buffers);
-	g_mutex_unlock(c->mutex);
-
-	return eof;
-}
-
-static int
-input_curl_buffer(struct input_stream *is, GError **error_r)
-{
-	struct input_curl *c = (struct input_curl *)is;
-
-	g_mutex_lock(c->mutex);
-
-	int result;
-	if (c->postponed_error != NULL) {
-		g_propagate_error(error_r, c->postponed_error);
-		c->postponed_error = NULL;
-		result = -1;
-	} else if (g_queue_is_empty(c->buffers))
-		result = 0;
-	else
-		result = 1;
-
-	g_mutex_unlock(c->mutex);
-
-	return result;
+	return c->easy == NULL && g_queue_is_empty(c->buffers);
 }
 
 /** called by curl when new data is available */
@@ -1092,12 +1060,12 @@ input_curl_writefunction(void *ptr, size_t size, size_t nmemb, void *stream)
 	if (size == 0)
 		return 0;
 
-	g_mutex_lock(c->mutex);
+	g_mutex_lock(c->base.mutex);
 
 #if LIBCURL_VERSION_NUM >= 0x071200
 	if (curl_total_buffer_size(c) + size >= CURL_MAX_BUFFERED) {
 		c->paused = true;
-		g_mutex_unlock(c->mutex);
+		g_mutex_unlock(c->base.mutex);
 		return CURL_WRITEFUNC_PAUSE;
 	}
 #endif
@@ -1108,11 +1076,10 @@ input_curl_writefunction(void *ptr, size_t size, size_t nmemb, void *stream)
 	memcpy(buffer->data, ptr, size);
 
 	g_queue_push_tail(c->buffers, buffer);
-
 	c->base.ready = true;
 
-	g_cond_broadcast(c->cond);
-	g_mutex_unlock(c->mutex);
+	g_cond_broadcast(c->base.cond);
+	g_mutex_unlock(c->base.mutex);
 
 	return size;
 }
@@ -1219,8 +1186,6 @@ input_curl_seek(struct input_stream *is, goffset offset, int whence,
 
 	/* check if we can fast-forward the buffer */
 
-	g_mutex_lock(c->mutex);
-
 	while (offset > is->offset && !g_queue_is_empty(c->buffers)) {
 		struct buffer *buffer;
 		size_t length;
@@ -1238,13 +1203,13 @@ input_curl_seek(struct input_stream *is, goffset offset, int whence,
 		is->offset += length;
 	}
 
-	g_mutex_unlock(c->mutex);
-
 	if (offset == is->offset)
 		return true;
 
 	/* close the old connection and open a new one */
 
+	g_mutex_unlock(c->base.mutex);
+
 	input_curl_easy_free_indirect(c);
 	input_curl_flush_buffers(c);
 
@@ -1272,36 +1237,35 @@ input_curl_seek(struct input_stream *is, goffset offset, int whence,
 	if (!input_curl_easy_add_indirect(c, error_r))
 		return false;
 
-	g_mutex_lock(c->mutex);
+	g_mutex_lock(c->base.mutex);
 
 	while (!c->base.ready)
-		g_cond_wait(c->cond, c->mutex);
+		g_cond_wait(c->base.cond, c->base.mutex);
 
 	if (c->postponed_error != NULL) {
 		g_propagate_error(error_r, c->postponed_error);
 		c->postponed_error = NULL;
-		g_mutex_unlock(c->mutex);
 		return false;
 	}
 
-	g_mutex_unlock(c->mutex);
-
 	return true;
 }
 
 static struct input_stream *
-input_curl_open(const char *url, GError **error_r)
+input_curl_open(const char *url, GMutex *mutex, GCond *cond,
+		GError **error_r)
 {
+	assert(mutex != NULL);
+	assert(cond != NULL);
+
 	struct input_curl *c;
 
 	if (strncmp(url, "http://", 7) != 0)
 		return NULL;
 
 	c = g_new0(struct input_curl, 1);
-	input_stream_init(&c->base, &input_plugin_curl, url);
-
-	c->mutex = g_mutex_new();
-	c->cond = g_cond_new();
+	input_stream_init(&c->base, &input_plugin_curl, url,
+			  mutex, cond);
 
 	c->url = g_strdup(url);
 	c->buffers = g_queue_new();
@@ -1337,7 +1301,7 @@ const struct input_plugin input_plugin_curl = {
 	.close = input_curl_close,
 	.check = input_curl_check,
 	.tag = input_curl_tag,
-	.buffer = input_curl_buffer,
+	.available = input_curl_available,
 	.read = input_curl_read,
 	.eof = input_curl_eof,
 	.seek = input_curl_seek,

src/input/despotify_input_plugin.c

@@ -97,7 +97,9 @@ static void callback(G_GNUC_UNUSED struct despotify_session* ds,
 
 
 static struct input_stream *
-input_despotify_open(const char *url, G_GNUC_UNUSED GError **error_r)
+input_despotify_open(const char *url,
+		     GMutex *mutex, GCond *cond,
+		     G_GNUC_UNUSED GError **error_r)
 {
 	struct input_despotify *ctx;
 	struct despotify_session *session;
@@ -131,7 +133,8 @@ input_despotify_open(const char *url, G_GNUC_UNUSED GError **error_r)
 		return NULL;
 	}
 
-	input_stream_init(&ctx->base, &input_plugin_despotify, url);
+	input_stream_init(&ctx->base, &input_plugin_despotify, url,
+			  mutex, cond);
 	ctx->session = session;
 	ctx->track = track;
 	ctx->tag = mpd_despotify_tag_from_track(track);

src/input/ffmpeg_input_plugin.c

@@ -74,7 +74,9 @@ input_ffmpeg_init(G_GNUC_UNUSED const struct config_param *param,
 }
 
 static struct input_stream *
-input_ffmpeg_open(const char *uri, GError **error_r)
+input_ffmpeg_open(const char *uri,
+		  GMutex *mutex, GCond *cond,
+		  GError **error_r)
 {
 	struct input_ffmpeg *i;
 
@@ -87,7 +89,8 @@ input_ffmpeg_open(const char *uri, GError **error_r)
 		return NULL;
 
 	i = g_new(struct input_ffmpeg, 1);
-	input_stream_init(&i->base, &input_plugin_ffmpeg, uri);
+	input_stream_init(&i->base, &input_plugin_ffmpeg, uri,
+			  mutex, cond);
 
 #if LIBAVFORMAT_VERSION_INT >= AV_VERSION_INT(53,1,0)
 	int ret = avio_open(&i->h, uri, AVIO_FLAG_READ);

src/input/file_input_plugin.c

@@ -46,7 +46,9 @@ file_quark(void)
 }
 
 static struct input_stream *
-input_file_open(const char *filename, GError **error_r)
+input_file_open(const char *filename,
+		GMutex *mutex, GCond *cond,
+		GError **error_r)
 {
 	int fd, ret;
 	struct stat st;
@@ -85,7 +87,8 @@ input_file_open(const char *filename, GError **error_r)
 #endif
 
 	fis = g_new(struct file_input_stream, 1);
-	input_stream_init(&fis->base, &input_plugin_file, filename);
+	input_stream_init(&fis->base, &input_plugin_file, filename,
+			  mutex, cond);
 
 	fis->base.size = st.st_size;
 	fis->base.seekable = true;

src/input/mms_input_plugin.c

@@ -46,7 +46,9 @@ mms_quark(void)
 }
 
 static struct input_stream *
-input_mms_open(const char *url, GError **error_r)
+input_mms_open(const char *url,
+	       GMutex *mutex, GCond *cond,
+	       GError **error_r)
 {
 	struct input_mms *m;
 
@@ -57,7 +59,8 @@ input_mms_open(const char *url, GError **error_r)
 		return NULL;
 
 	m = g_new(struct input_mms, 1);
-	input_stream_init(&m->base, &input_plugin_mms, url);
+	input_stream_init(&m->base, &input_plugin_mms, url,
+			  mutex, cond);
 
 	m->mms = mmsx_connect(NULL, NULL, url, 128 * 1024);
 	if (m->mms == NULL) {

src/input/rewind_input_plugin.c

@@ -132,16 +132,12 @@ input_rewind_tag(struct input_stream *is)
 	return input_stream_tag(r->input);
 }
 
-static int
-input_rewind_buffer(struct input_stream *is, GError **error_r)
+static bool
+input_rewind_available(struct input_stream *is)
 {
 	struct input_rewind *r = (struct input_rewind *)is;
 
-	int ret = input_stream_buffer(r->input, error_r);
-	if (ret < 0 || !reading_from_buffer(r))
-		copy_attributes(r);
-
-	return ret;
+	return input_stream_available(r->input);
 }
 
 static size_t
@@ -232,7 +228,7 @@ static const struct input_plugin rewind_input_plugin = {
 	.check = input_rewind_check,
 	.update = input_rewind_update,
 	.tag = input_rewind_tag,
-	.buffer = input_rewind_buffer,
+	.available = input_rewind_available,
 	.read = input_rewind_read,
 	.eof = input_rewind_eof,
 	.seek = input_rewind_seek,
@@ -251,7 +247,8 @@ input_rewind_open(struct input_stream *is)
 		return is;
 
 	c = g_new(struct input_rewind, 1);
-	input_stream_init(&c->base, &rewind_input_plugin, is->uri);
+	input_stream_init(&c->base, &rewind_input_plugin, is->uri,
+			  is->mutex, is->cond);
 	c->tail = 0;
 	c->input = is;
 

src/input/soup_input_plugin.c

@@ -46,9 +46,6 @@ static SoupSession *soup_session;
 struct input_soup {
 	struct input_stream base;
 
-	GMutex *mutex;
-	GCond *cond;
-
 	SoupMessage *msg;
 
 	GQueue *buffers;
@@ -124,14 +121,14 @@ input_soup_session_callback(G_GNUC_UNUSED SoupSession *session,
 	assert(msg == s->msg);
 	assert(!s->completed);
 
-	g_mutex_lock(s->mutex);
+	g_mutex_lock(s->base.mutex);
 
 	s->base.ready = true;
 	s->alive = false;
 	s->completed = true;
 
-	g_cond_broadcast(s->cond);
-	g_mutex_unlock(s->mutex);
+	g_cond_broadcast(s->base.cond);
+	g_mutex_unlock(s->base.mutex);
 }
 
 static void
@@ -140,7 +137,7 @@ input_soup_got_headers(SoupMessage *msg, gpointer user_data)
 	struct input_soup *s = user_data;
 
 	if (!SOUP_STATUS_IS_SUCCESSFUL(msg->status_code)) {
-		g_mutex_lock(s->mutex);
+		g_mutex_lock(s->base.mutex);
 
 		if (s->postponed_error == NULL)
 			s->postponed_error =
@@ -148,7 +145,7 @@ input_soup_got_headers(SoupMessage *msg, gpointer user_data)
 					    "got HTTP status %d",
 					    msg->status_code);
 
-		g_mutex_unlock(s->mutex);
+		g_mutex_unlock(s->base.mutex);
 
 		soup_session_cancel_message(soup_session, msg,
 					    SOUP_STATUS_CANCELLED);
@@ -157,10 +154,10 @@ input_soup_got_headers(SoupMessage *msg, gpointer user_data)
 
 	soup_message_body_set_accumulate(msg->response_body, false);
 
-	g_mutex_lock(s->mutex);
+	g_mutex_lock(s->base.mutex);
 	s->base.ready = true;
-	g_cond_broadcast(s->cond);
-	g_mutex_unlock(s->mutex);
+	g_cond_broadcast(s->base.cond);
+	g_mutex_unlock(s->base.mutex);
 }
 
 static void
@@ -170,7 +167,7 @@ input_soup_got_chunk(SoupMessage *msg, SoupBuffer *chunk, gpointer user_data)
 
 	assert(msg == s->msg);
 
-	g_mutex_lock(s->mutex);
+	g_mutex_lock(s->base.mutex);
 
 	g_queue_push_tail(s->buffers, soup_buffer_copy(chunk));
 	s->total_buffered += chunk->length;
@@ -180,8 +177,8 @@ input_soup_got_chunk(SoupMessage *msg, SoupBuffer *chunk, gpointer user_data)
 		soup_session_pause_message(soup_session, msg);
 	}
 
-	g_cond_broadcast(s->cond);
-	g_mutex_unlock(s->mutex);
+	g_cond_broadcast(s->base.cond);
+	g_mutex_unlock(s->base.mutex);
 }
 
 static void
@@ -191,14 +188,14 @@ input_soup_got_body(G_GNUC_UNUSED SoupMessage *msg, gpointer user_data)
 
 	assert(msg == s->msg);
 
-	g_mutex_lock(s->mutex);
+	g_mutex_lock(s->base.mutex);
 
 	s->base.ready = true;
 	s->eof = true;
 	s->alive = false;
 
-	g_cond_broadcast(s->cond);
-	g_mutex_unlock(s->mutex);
+	g_cond_broadcast(s->base.cond);
+	g_mutex_unlock(s->base.mutex);
 }
 
 static bool
@@ -216,7 +213,7 @@ input_soup_wait_data(struct input_soup *s)
 
 		assert(s->current_consumed == 0);
 
-		g_cond_wait(s->cond, s->mutex);
+		g_cond_wait(s->base.cond, s->base.mutex);
 	}
 }
 
@@ -232,16 +229,16 @@ input_soup_queue(gpointer data)
 }
 
 static struct input_stream *
-input_soup_open(const char *uri, G_GNUC_UNUSED GError **error_r)
+input_soup_open(const char *uri,
+		GMutex *mutex, GCond *cond,
+		G_GNUC_UNUSED GError **error_r)
 {
 	if (strncmp(uri, "http://", 7) != 0)
 		return NULL;
 
 	struct input_soup *s = g_new(struct input_soup, 1);
-	input_stream_init(&s->base, &input_plugin_soup, uri);
-
-	s->mutex = g_mutex_new();
-	s->cond = g_cond_new();
+	input_stream_init(&s->base, &input_plugin_soup, uri,
+			  mutex, cond);
 
 	s->buffers = g_queue_new();
 	s->current_consumed = 0;
@@ -288,25 +285,22 @@ input_soup_close(struct input_stream *is)
 {
 	struct input_soup *s = (struct input_soup *)is;
 
-	g_mutex_lock(s->mutex);
+	g_mutex_lock(s->base.mutex);
 
 	if (!s->completed) {
 		/* the messages's session callback hasn't been invoked
 		   yet; cancel it and wait for completion */
 
-		g_mutex_unlock(s->mutex);
+		g_mutex_unlock(s->base.mutex);
 
 		io_thread_call(input_soup_cancel, s);
 
-		g_mutex_lock(s->mutex);
+		g_mutex_lock(s->base.mutex);
 		while (!s->completed)
-			g_cond_wait(s->cond, s->mutex);
+			g_cond_wait(s->base.cond, s->base.mutex);
 	}
 
-	g_mutex_unlock(s->mutex);
-
-	g_mutex_free(s->mutex);
-	g_cond_free(s->cond);
+	g_mutex_unlock(s->base.mutex);
 
 	SoupBuffer *buffer;
 	while ((buffer = g_queue_pop_head(s->buffers)) != NULL)
@@ -325,54 +319,21 @@ input_soup_check(struct input_stream *is, GError **error_r)
 {
 	struct input_soup *s = (struct input_soup *)is;
 
-	g_mutex_lock(s->mutex);
-
 	bool success = s->postponed_error == NULL;
 	if (!success) {
 		g_propagate_error(error_r, s->postponed_error);
 		s->postponed_error = NULL;
 	}
 
-	g_mutex_unlock(s->mutex);
 	return success;
 }
 
-static int
-input_soup_buffer(struct input_stream *is, GError **error_r)
+static bool
+input_soup_available(struct input_stream *is)
 {
 	struct input_soup *s = (struct input_soup *)is;
 
-	g_mutex_lock(s->mutex);
-
-	if (s->pause) {
-		if (s->total_buffered >= SOUP_MAX_BUFFERED) {
-			g_mutex_unlock(s->mutex);
-			return 1;
-		}
-
-		s->pause = false;
-		soup_session_unpause_message(soup_session, s->msg);
-	}
-
-
-	bool success = input_soup_wait_data(s);
-
-	if (!success) {
-		if (s->postponed_error != NULL) {
-			g_propagate_error(error_r, s->postponed_error);
-			s->postponed_error = NULL;
-		} else
-			g_set_error_literal(error_r, soup_quark(), 0,
-					    "HTTP failure");
-	}
-
-	g_mutex_unlock(s->mutex);
-
-	if (!success) {
-		return -1;
-	}
-
-	return 1;
+	return s->eof || !s->alive || !g_queue_is_empty(s->buffers);
 }
 
 static size_t
@@ -381,8 +342,6 @@ input_soup_read(struct input_stream *is, void *ptr, size_t size,
 {
 	struct input_soup *s = (struct input_soup *)is;
 
-	g_mutex_lock(s->mutex);
-
 	if (!input_soup_wait_data(s)) {
 		assert(!s->alive);
 
@@ -392,8 +351,6 @@ input_soup_read(struct input_stream *is, void *ptr, size_t size,
 		} else
 			g_set_error_literal(error_r, soup_quark(), 0,
 					    "HTTP failure");
-
-		g_mutex_unlock(s->mutex);
 		return 0;
 	}
 
@@ -442,7 +399,6 @@ input_soup_read(struct input_stream *is, void *ptr, size_t size,
 	size_t nbytes = p - p0;
 	s->base.offset += nbytes;
 
-	g_mutex_unlock(s->mutex);
 	return nbytes;
 }
 
@@ -462,7 +418,7 @@ const struct input_plugin input_plugin_soup = {
 	.open = input_soup_open,
 	.close = input_soup_close,
 	.check = input_soup_check,
-	.buffer = input_soup_buffer,
+	.available = input_soup_available,
 	.read = input_soup_read,
 	.eof = input_soup_eof,
 };