protect stream poll against race condition - release

components/squeezelite/mad.c

@@ -243,6 +243,8 @@ static decode_state mad_decode(void) {
 		MAD(m, synth_frame, &m->synth, &m->frame);
 
 		if (decode.new_stream) {
+			// seems that mad can use some help in term of sync detection
+			if (m->stream.next_frame[0] != 0xff || (m->stream.next_frame[1] & 0xf0) != 0xf0) continue;
 			LOCK_O;
 			LOG_INFO("setting track_start");
 			output.next_sample_rate = decode_newstream(m->synth.pcm.samplerate, output.supported_rates);
@@ -417,3 +419,4 @@ struct codec *register_mad(void) {
 	LOG_INFO("using mad to decode mp3");
 	return &ret;
 }
+

components/squeezelite/stream.c

@@ -40,6 +40,7 @@
 static log_level loglevel;
 
 static struct buffer buf;
+static mutex_type poll_mutex;
 struct buffer *streambuf = &buf;
 
 #define LOCK   mutex_lock(streambuf->mutex)
@@ -196,7 +197,11 @@ static void *stream_thread() {
 
 		UNLOCK;
 		
-		if (_poll(ssl, &pollinfo, 100)) {
+		mutex_lock(poll_mutex);
+		int pending = _poll(ssl, &pollinfo, 100);
+		mutex_unlock(poll_mutex);
+
+		if (pending) {
 			
 			LOCK;
 
@@ -350,7 +355,6 @@ static void *stream_thread() {
 			UNLOCK;
 			
 		} else {
-			
 			LOG_SDEBUG("poll timeout");
 		}
 	}
@@ -403,6 +407,7 @@ void stream_init(log_level level, unsigned stream_buf_size) {
 	*stream.header = '\0';
 
 	fd = -1;
+	mutex_create_p(poll_mutex);
 
 #if LINUX || FREEBSD
 	touch_memory(streambuf->buf, streambuf->size);
@@ -432,6 +437,7 @@ void stream_close(void) {
 #endif
 	free(stream.header);
 	buf_destroy(streambuf);
+	mutex_destroy(poll_mutex);
 }
 
 void stream_file(const char *header, size_t header_len, unsigned threshold) {
@@ -573,6 +579,7 @@ void stream_sock(u32_t ip, u16_t port, const char *header, size_t header_len, un
 
 bool stream_disconnect(void) {
 	bool disc = false;
+	mutex_lock(poll_mutex);
 	LOCK;
 #if USE_SSL
 	if (ssl) {
@@ -588,5 +595,6 @@ bool stream_disconnect(void) {
 	}
 	stream.state = STOPPED;
 	UNLOCK;
+	mutex_unlock(poll_mutex);
 	return disc;
 }