diff --git a/trunk/src/protocol/srs_service_st_srt.cpp b/trunk/src/protocol/srs_service_st_srt.cpp
index d2f580911..9aed09fdd 100644
--- a/trunk/src/protocol/srs_service_st_srt.cpp
+++ b/trunk/src/protocol/srs_service_st_srt.cpp
@@ -549,25 +549,26 @@ srs_error_t SrsSrtSocket::connect(const string& ip, int port)
 
     // @see https://github.com/Haivision/srt/blob/master/docs/API/API-functions.md#srt_connect
     int ret = srt_connect(srt_fd_, (const sockaddr*)&inaddr, sizeof(inaddr));
+    if (ret != 0) {
+        return srs_error_new(ERROR_SRT_IO, "srt_connect, err=%s", srt_getlasterror_str());
+    }
 
-    if (ret == 0) {
-        // Connect succuess, in async mode, means SRT API succuess and return directly,
-        // and the connection is in progress, like tcp socket API connect errno EINPROGRESS,
-        // and the SRT IO threads will do the real handshake step to finish srt connect.
-        SRT_SOCKSTATUS srt_status = srt_getsockstate(srt_fd_);
-        if (srt_status != SRTS_CONNECTED) {
-            // Connect is in progress, wait until it finish or error.
-            if ((err = wait_writeable()) != srs_success) {
-                return srs_error_wrap(err, "wait writeable");
-            }
+    // Connect succeed, in async mode, means SRT API succeed and return directly,
+    // and the connection is in progress, like tcp socket API connect errno EINPROGRESS,
+    // and the SRT IO threads will do the real handshake step to finish srt connect.
+    SRT_SOCKSTATUS srt_status = srt_getsockstate(srt_fd_);
+    if (srt_status == SRTS_CONNECTED) {
+        return err;
+    }
 
-            // Double check if connect is established.
-            srt_status = srt_getsockstate(srt_fd_);
-            if (srt_status != SRTS_CONNECTED) {
-                return srs_error_new(ERROR_SRT_IO, "srt_connect, err=%s", srt_getlasterror_str());
-            }
-        }
-    } else {
+    // Connect is in progress, wait until it finish or error.
+    if ((err = wait_writeable()) != srs_success) {
+        return srs_error_wrap(err, "wait writeable");
+    }
+
+    // Double check if connect is established.
+    srt_status = srt_getsockstate(srt_fd_);
+    if (srt_status != SRTS_CONNECTED) {
         return srs_error_new(ERROR_SRT_IO, "srt_connect, err=%s", srt_getlasterror_str());
     }
 
@@ -583,19 +584,21 @@ srs_error_t SrsSrtSocket::accept(SRTSOCKET* client_srt_fd)
         int addrlen = sizeof(inaddr);
         // @see https://github.com/Haivision/srt/blob/master/docs/API/API-functions.md#srt_accept
         SRTSOCKET srt_fd = srt_accept(srt_fd_, (sockaddr*)&inaddr, &addrlen);
-        if (srt_fd == SRT_INVALID_SOCK) {
-            if (srt_getlasterror(NULL) == SRT_EASYNCRCV) {
-                // Accept would block, wait until new client connect or error.
-                if ((err = wait_readable()) != srs_success) {
-                    return srs_error_wrap(err, "wait readable");
-                }
-                continue;
-            } else {
-                return srs_error_new(ERROR_SRT_IO, "srt_accept, err=%s", srt_getlasterror_str());
-            }
-        } else {
+
+        // Accept ok, return with the SRT client fd.
+        if (srt_fd != SRT_INVALID_SOCK) {
             *client_srt_fd = srt_fd;
-            break;
+            return err;
+        }
+
+        // Got something error, return immediately.
+        if (srt_getlasterror(NULL) != SRT_EASYNCRCV) {
+            return srs_error_new(ERROR_SRT_IO, "srt_accept, err=%s", srt_getlasterror_str());
+        }
+
+        // Accept would block, wait until new client connect or error.
+        if ((err = wait_readable()) != srs_success) {
+            return srs_error_wrap(err, "wait readable");
         }
     }
 
@@ -609,19 +612,22 @@ srs_error_t SrsSrtSocket::recvmsg(void* buf, size_t size, ssize_t* nread)
     while (true) {
         // @see https://github.com/Haivision/srt/blob/master/docs/API/API-functions.md#srt_recvmsg
         int ret = srt_recvmsg(srt_fd_, (char*)buf, size);
-        if (ret < 0) {
-            if (srt_getlasterror(NULL) == SRT_EASYNCRCV) {
-                if ((err = wait_readable()) != srs_success) {
-                    return srs_error_wrap(err, "wait readable");
-                }
-                continue;
-            } else {
-                return srs_error_new(ERROR_SRT_IO, "srt_recvmsg, err=%s", srt_getlasterror_str());
-            }
-        } else {
+
+        // Receive message ok.
+        if (ret >= 0) {
             recv_bytes_ += ret;
             *nread = ret;
-            break;
+            return err;
+        }
+
+        // Got something error, return immediately.
+        if (srt_getlasterror(NULL) != SRT_EASYNCRCV) {
+            return srs_error_new(ERROR_SRT_IO, "srt_recvmsg, err=%s", srt_getlasterror_str());
+        }
+
+        // Wait for the fd ready or error, switch to other coroutines.
+        if ((err = wait_readable()) != srs_success) {
+            return srs_error_wrap(err, "wait readable");
         }
     }
 
@@ -635,19 +641,22 @@ srs_error_t SrsSrtSocket::sendmsg(void* buf, size_t size, ssize_t* nwrite)
     while (true) {
         // @see https://github.com/Haivision/srt/blob/master/docs/API/API-functions.md#srt_sendmsg
         int ret = srt_sendmsg(srt_fd_, (const char*)buf, size, -1, 1);
-        if (ret < 0) {
-            if (srt_getlasterror(NULL) == SRT_EASYNCSND) {
-                if ((err = wait_writeable()) != srs_success) {
-                    return srs_error_wrap(err, "wait writeable");
-                }
-                continue;
-            } else {
-                return srs_error_new(ERROR_SRT_IO, "srt_sendmsg, err=%s", srt_getlasterror_str());
-            }
-        } else {
+
+        // Send message ok.
+        if (ret >= 0) {
             send_bytes_ += ret;
             *nwrite = ret;
-            break;
+            return err;
+        }
+
+        // Got something error, return immediately.
+        if (srt_getlasterror(NULL) != SRT_EASYNCSND) {
+            return srs_error_new(ERROR_SRT_IO, "srt_sendmsg, err=%s", srt_getlasterror_str());
+        }
+
+        // Wait for the fd ready or error, switch to other coroutines.
+        if ((err = wait_writeable()) != srs_success) {
+            return srs_error_wrap(err, "wait writeable");
         }
     }
 
@@ -671,8 +680,7 @@ srs_error_t SrsSrtSocket::wait_readable()
     // Wait event fired or timeout.
     int ret = srs_cond_timedwait(read_cond_, recv_timeout_);
     // TODO: FIXME: need to disable it?
-    err = disable_read();
-    if (err != srs_success) {
+    if ((err = disable_read()) != srs_success) {
         srs_freep(err);
     }
 
@@ -709,8 +717,7 @@ srs_error_t SrsSrtSocket::wait_writeable()
     }
 
     int ret = srs_cond_timedwait(write_cond_, send_timeout_);
-    err = disable_write();
-    if (err != srs_success) {
+    if ((err = disable_write()) != srs_success) {
         srs_freep(err);
     }
 
@@ -769,8 +776,10 @@ srs_error_t SrsSrtSocket::disable_write()
     return disable_event(SRT_EPOLL_OUT);
 }
 
-srs_error_t SrsSrtSocket::enable_event(int event) {
+srs_error_t SrsSrtSocket::enable_event(int event)
+{
     srs_error_t err = srs_success;
+
     // Event has been subscribed.
     if ((events_ & event) == event) {
         return err;
@@ -784,11 +793,14 @@ srs_error_t SrsSrtSocket::enable_event(int event) {
     } else {
         err = srt_poller_->mod_socket(this);
     }
+
     return err;
 }
 
-srs_error_t SrsSrtSocket::disable_event(int event) {
+srs_error_t SrsSrtSocket::disable_event(int event)
+{
     srs_error_t err = srs_success;
+
     // Event has been unsubscribed.
     if ((events_ & event) == 0) {
         return err;
@@ -801,10 +813,12 @@ srs_error_t SrsSrtSocket::disable_event(int event) {
     } else {
         err = srt_poller_->mod_socket(this);
     }
+
     return err;
 }
 
-srs_error_t SrsSrtSocket::check_error() {
+srs_error_t SrsSrtSocket::check_error()
+{
     srs_error_t err = srs_success;
 
     if (has_error_) {
diff --git a/trunk/src/utest/srs_utest.cpp b/trunk/src/utest/srs_utest.cpp
index f2478eb9f..52365b942 100644
--- a/trunk/src/utest/srs_utest.cpp
+++ b/trunk/src/utest/srs_utest.cpp
@@ -36,10 +36,6 @@ SrsConfig* _srs_config = NULL;
 SrsServer* _srs_server = NULL;
 bool _srs_in_docker = false;
 
-#ifdef SRS_SRT
-SrsSrtEventLoop* _srt_eventloop = NULL;
-#endif
-
 #include <srs_app_st.hpp>
 
 // Initialize global settings.