check for shutdown condition while waiting for first sample

Author: tstenner

recording.cpp

@@ -374,7 +374,7 @@ void recording::typed_transfer_loop(streamid_t streamid, double srate, const inl
 
 		// Pull the first sample
 		first_timestamp = 0.0;
-		while(first_timestamp == 0.0)
+		while(!shutdown_ && first_timestamp == 0.0)
 			first_timestamp = last_timestamp = in->pull_sample(chunk, 4.0);
 		timestamps.push_back(first_timestamp);
 		file_.write_data_chunk(streamid, timestamps, chunk, in->get_channel_count());