diff --git a/trunk/src/app/srs_app_rtc_conn.cpp b/trunk/src/app/srs_app_rtc_conn.cpp
index 24c19663c..a2d7c9c7a 100644
--- a/trunk/src/app/srs_app_rtc_conn.cpp
+++ b/trunk/src/app/srs_app_rtc_conn.cpp
@@ -701,22 +701,25 @@ srs_error_t SrsRtcSenderThread::cycle()
             return srs_error_wrap(err, "rtc sender thread");
         }
 
+#ifdef SRS_PERF_QUEUE_COND_WAIT
+        // Wait for amount of messages or a duration.
+        if (realtime) {
+            // for realtime, min required msgs is 0, send when got one+ msgs.
+            consumer->wait(SRS_PERF_MW_MIN_MSGS_FOR_RTC_REALTIME, mw_sleep);
+        } else {
+            // for no-realtime, got some msgs then send.
+            consumer->wait(SRS_PERF_MW_MIN_MSGS_FOR_RTC, mw_sleep);
+        }
+#endif
+
+        // Try to read some messages.
         int msg_count = 0;
         if ((err = consumer->dump_packets(&msgs, msg_count)) != srs_success) {
             continue;
         }
 
-        // For RTC, we always try to read messages, only wait when no message.
         if (msg_count <= 0) {
-#ifdef SRS_PERF_QUEUE_COND_WAIT
-            if (realtime) {
-                // for realtime, min required msgs is 0, send when got one+ msgs.
-                consumer->wait(SRS_PERF_MW_MIN_MSGS_FOR_RTC_REALTIME, mw_sleep);
-            } else {
-                // for no-realtime, got some msgs then send.
-                consumer->wait(SRS_PERF_MW_MIN_MSGS_FOR_RTC, mw_sleep);
-            }
-#else
+#ifndef SRS_PERF_QUEUE_COND_WAIT
             srs_usleep(mw_sleep);
 #endif
             continue;