diff --git a/examples/performance/tcp_perf/main/Kconfig.projbuild b/examples/performance/tcp_perf/main/Kconfig.projbuild
index 92bf8387f..7c95b49bc 100644
--- a/examples/performance/tcp_perf/main/Kconfig.projbuild
+++ b/examples/performance/tcp_perf/main/Kconfig.projbuild
@@ -103,6 +103,7 @@ config TCP_PERF_SERVER_PORT
 				
 config TCP_PERF_SERVER_IP
     string "TCP server ip"
+    depends on TCP_PERF_ESP_IS_CLIENT
     default "192.168.4.1" 
     help
 	IP of TCP server.
diff --git a/examples/performance/tcp_perf/main/tcp_main.c b/examples/performance/tcp_perf/main/tcp_main.c
index fbb65c0f0..bb86700a7 100644
--- a/examples/performance/tcp_perf/main/tcp_main.c
+++ b/examples/performance/tcp_perf/main/tcp_main.c
@@ -1,3 +1,11 @@
+/* tcp_perf Example
+
+   This example code is in the Public Domain (or CC0 licensed, at your option.)
+
+   Unless required by applicable law or agreed to in writing, this
+   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+   CONDITIONS OF ANY KIND, either express or implied.
+*/
 
 
 /*
@@ -22,6 +30,7 @@ step3:
 #include <errno.h>
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
+#include "freertos/event_groups.h"
 #include "esp_log.h"
 #include "esp_err.h"
 
@@ -32,63 +41,62 @@ step3:
 //this task establish a TCP connection and receive data from TCP
 static void tcp_conn(void *pvParameters)
 {
-    ESP_LOGI(TAG, "task tcp_conn start.");
+    ESP_LOGI(TAG, "task tcp_conn.");
     /*wating for connecting to AP*/
-    do
-    {
-	vTaskDelay(100);
-    }
-    while (!connectedflag);
+    xEventGroupWaitBits(tcp_event_group, WIFI_CONNECTED_BIT,false, true, portMAX_DELAY);
+
     ESP_LOGI(TAG, "sta has connected to ap.");
     
     /*create tcp socket*/
     int socket_ret;
     
-#if ESP_TCP_MODE_SERVER
+#if EXAMPLE_ESP_TCP_MODE_SERVER
+    ESP_LOGI(TAG, "tcp_server will start after 3s...");
     vTaskDelay(3000 / portTICK_RATE_MS);
     ESP_LOGI(TAG, "create_tcp_server.");
     socket_ret=create_tcp_server();
-#else /*ESP_TCP_MODE_SERVER*/
+#else /*EXAMPLE_ESP_TCP_MODE_SERVER*/
+    ESP_LOGI(TAG, "tcp_client will start after 20s...");
     vTaskDelay(20000 / portTICK_RATE_MS);
     ESP_LOGI(TAG, "create_tcp_client.");
     socket_ret = create_tcp_client();
 #endif
-    if(ESP_FAIL == socket_ret) {
+    if(socket_ret == ESP_FAIL) {
 	ESP_LOGI(TAG, "create tcp socket error,stop.");
 	vTaskDelete(NULL);
     }
     
     /*create a task to tx/rx data*/
     TaskHandle_t tx_rx_task;
-#if ESP_TCP_PERF_TX
+#if EXAMPLE_ESP_TCP_PERF_TX
     xTaskCreate(&send_data, "send_data", 4096, NULL, 4, &tx_rx_task);
-#else /*ESP_TCP_PERF_TX*/
+#else /*EXAMPLE_ESP_TCP_PERF_TX*/
     xTaskCreate(&recv_data, "recv_data", 4096, NULL, 4, &tx_rx_task);
 #endif
-    int pps;
+    int bps;
     while (1) {
 	total_data = 0;
 	vTaskDelay(3000 / portTICK_RATE_MS);//every 3s
-	pps = total_data / 3;
+	bps = total_data / 3;
 	if (total_data <= 0) {
-	    int err_ret = check_socket_error_code();
-	    if (err_ret == ECONNRESET) {
-		ESP_LOGI(TAG, "disconnected... stop.");
+	    int err_ret = check_working_socket();
+	    if (err_ret == ECONNRESET || ECONNABORTED) {
+		ESP_LOGW(TAG, "tcp disconnected... stop.\n");
 		break;
 	    }
 	}
 
-#if ESP_TCP_PERF_TX
-	ESP_LOGI(TAG, "tcp send %d byte per sec!", pps);
-#if ESP_TCP_DELAY_INFO
+#if EXAMPLE_ESP_TCP_PERF_TX
+	ESP_LOGI(TAG, "tcp send %d byte per sec!", bps);
+#if EXAMPLE_ESP_TCP_DELAY_INFO
 	ESP_LOGI(TAG, "tcp send packet total:%d  succeed:%d  failed:%d\n"
 		"time(ms):0-30:%d 30-100:%d 100-300:%d 300-1000:%d 1000+:%d\n",
 		total_pack, send_success, send_fail, delay_classify[0],
 		delay_classify[1], delay_classify[2], delay_classify[3], delay_classify[4]);
-#endif /*ESP_TCP_DELAY_INFO*/
+#endif /*EXAMPLE_ESP_TCP_DELAY_INFO*/
 #else
-	ESP_LOGI(TAG, "tcp recv %d byte per sec!\n", pps);
-#endif /*ESP_TCP_PERF_TX*/
+	ESP_LOGI(TAG, "tcp recv %d byte per sec!\n", bps);
+#endif /*EXAMPLE_ESP_TCP_PERF_TX*/
     }
     close_socket();
     vTaskDelete(tx_rx_task);
@@ -99,12 +107,12 @@ static void tcp_conn(void *pvParameters)
 
 void app_main(void)
 {
-#if ESP_WIFI_MODE_AP
-    ESP_LOGI(TAG, "ESP_WIFI_MODE_AP\n");
+#if EXAMPLE_ESP_WIFI_MODE_AP
+    ESP_LOGI(TAG, "EXAMPLE_ESP_WIFI_MODE_AP");
     wifi_init_softap();
-#else /*ESP_WIFI_MODE_AP*/
-    ESP_LOGI(TAG, "ESP_WIFI_MODE_STA\n");
+#else
+    ESP_LOGI(TAG, "ESP_WIFI_MODE_STA");
     wifi_init_sta();
-#endif
+#endif /*EXAMPLE_ESP_WIFI_MODE_AP*/
     xTaskCreate(&tcp_conn, "tcp_conn", 4096, NULL, 5, NULL);
 }
diff --git a/examples/performance/tcp_perf/main/tcp_perf.c b/examples/performance/tcp_perf/main/tcp_perf.c
index 0b8447ee9..d0c817147 100644
--- a/examples/performance/tcp_perf/main/tcp_perf.c
+++ b/examples/performance/tcp_perf/main/tcp_perf.c
@@ -1,21 +1,17 @@
-// Copyright 2013-2016 Espressif Systems (Shanghai) PTE LTD
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+/* tcp_perf Example
+
+   This example code is in the Public Domain (or CC0 licensed, at your option.)
+
+   Unless required by applicable law or agreed to in writing, this
+   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+   CONDITIONS OF ANY KIND, either express or implied.
+*/
 
 #include <string.h>
 #include <sys/socket.h>
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
+#include "freertos/event_groups.h"
 #include "esp_wifi.h"
 #include "esp_event_loop.h"
 #include "esp_log.h"
@@ -23,6 +19,10 @@
 
 #include "tcp_perf.h"
 
+
+/* FreeRTOS event group to signal when we are connected to wifi */
+EventGroupHandle_t tcp_event_group;
+
 /*socket*/
 static int server_socket = 0;
 static struct sockaddr_in server_addr;
@@ -30,17 +30,18 @@ static struct sockaddr_in client_addr;
 static unsigned int socklen = sizeof(client_addr);
 static int connect_socket = 0;
 
-int connectedflag = 0;
 int total_data = 0;
 
-#if ESP_TCP_PERF_TX && ESP_TCP_DELAY_INFO
+#if EXAMPLE_ESP_TCP_PERF_TX && EXAMPLE_ESP_TCP_DELAY_INFO
 
 int total_pack = 0;
 int send_success = 0;
 int send_fail = 0;
 int delay_classify[5] = { 0 };
 
-#endif /*ESP_TCP_PERF_TX && ESP_TCP_DELAY_INFO*/
+#endif /*EXAMPLE_ESP_TCP_PERF_TX && EXAMPLE_ESP_TCP_DELAY_INFO*/
+
+
 
 
 static esp_err_t event_handler(void *ctx, system_event_t *event)
@@ -51,26 +52,26 @@ static esp_err_t event_handler(void *ctx, system_event_t *event)
         break;
     case SYSTEM_EVENT_STA_DISCONNECTED:
         esp_wifi_connect();
+        xEventGroupClearBits(tcp_event_group, WIFI_CONNECTED_BIT);
         break;
     case SYSTEM_EVENT_STA_CONNECTED:
         break;
     case SYSTEM_EVENT_STA_GOT_IP:
-    	ESP_LOGI(TAG, "event_handler:SYSTEM_EVENT_STA_GOT_IP!");
     	ESP_LOGI(TAG, "got ip:%s\n",
 		ip4addr_ntoa(&event->event_info.got_ip.ip_info.ip));
-        connectedflag = 1;
+    	xEventGroupSetBits(tcp_event_group, WIFI_CONNECTED_BIT);
         break;
     case SYSTEM_EVENT_AP_STACONNECTED:
     	ESP_LOGI(TAG, "station:"MACSTR" join,AID=%d\n",
 		MAC2STR(event->event_info.sta_connected.mac),
 		event->event_info.sta_connected.aid);
-    	connectedflag = 1;
+    	xEventGroupSetBits(tcp_event_group, WIFI_CONNECTED_BIT);
     	break;
     case SYSTEM_EVENT_AP_STADISCONNECTED:
     	ESP_LOGI(TAG, "station:"MACSTR"leave,AID=%d\n",
 		MAC2STR(event->event_info.sta_disconnected.mac),
 		event->event_info.sta_disconnected.aid);
-    	connectedflag = 0;
+    	xEventGroupClearBits(tcp_event_group, WIFI_CONNECTED_BIT);
     	break;
     default:
         break;
@@ -82,33 +83,33 @@ static esp_err_t event_handler(void *ctx, system_event_t *event)
 void send_data(void *pvParameters)
 {
     int len = 0;
-    char databuff[DEFAULT_PKTSIZE];
-    memset(databuff, PACK_BYTE_IS, DEFAULT_PKTSIZE);
+    char databuff[EXAMPLE_DEFAULT_PKTSIZE];
+    memset(databuff, EXAMPLE_PACK_BYTE_IS, EXAMPLE_DEFAULT_PKTSIZE);
     vTaskDelay(100/portTICK_RATE_MS);
     ESP_LOGI(TAG, "start sending...");
-#if ESP_TCP_PERF_TX && ESP_TCP_DELAY_INFO
+#if EXAMPLE_ESP_TCP_PERF_TX && EXAMPLE_ESP_TCP_DELAY_INFO
     //delaytime
     struct timeval tv_start;
     struct timeval tv_finish;
     unsigned long send_delay_ms;
-#endif /*ESP_TCP_PERF_TX && ESP_TCP_DELAY_INFO*/
+#endif /*EXAMPLE_ESP_TCP_PERF_TX && EXAMPLE_ESP_TCP_DELAY_INFO*/
     while(1) {
 
-#if ESP_TCP_PERF_TX && ESP_TCP_DELAY_INFO
+#if EXAMPLE_ESP_TCP_PERF_TX && EXAMPLE_ESP_TCP_DELAY_INFO
     	total_pack++;
     	gettimeofday(&tv_start, NULL);
-#endif /*ESP_TCP_PERF_TX && ESP_TCP_DELAY_INFO*/
+#endif /*EXAMPLE_ESP_TCP_PERF_TX && EXAMPLE_ESP_TCP_DELAY_INFO*/
     	
 	//send function
-    	len = send(connect_socket, databuff, DEFAULT_PKTSIZE, 0);
+    	len = send(connect_socket, databuff, EXAMPLE_DEFAULT_PKTSIZE, 0);
 
-#if ESP_TCP_PERF_TX && ESP_TCP_DELAY_INFO
+#if EXAMPLE_ESP_TCP_PERF_TX && EXAMPLE_ESP_TCP_DELAY_INFO
     	gettimeofday(&tv_finish, NULL);
-#endif /*ESP_TCP_PERF_TX && ESP_TCP_DELAY_INFO*/
+#endif /*EXAMPLE_ESP_TCP_PERF_TX && EXAMPLE_ESP_TCP_DELAY_INFO*/
 	if(len > 0) {
 	    total_data += len;
 	    
-#if ESP_TCP_PERF_TX && ESP_TCP_DELAY_INFO
+#if EXAMPLE_ESP_TCP_PERF_TX && EXAMPLE_ESP_TCP_DELAY_INFO
 	    send_success++;
 	    send_delay_ms = (tv_finish.tv_sec - tv_start.tv_sec) * 1000
 		+ (tv_finish.tv_usec - tv_start.tv_usec) / 1000;
@@ -122,37 +123,34 @@ void send_data(void *pvParameters)
 		delay_classify[3]++;
 	    else
 		delay_classify[4]++;
-#endif /*ESP_TCP_PERF_TX && ESP_TCP_DELAY_INFO*/
+#endif /*EXAMPLE_ESP_TCP_PERF_TX && EXAMPLE_ESP_TCP_DELAY_INFO*/
 	
-	}/*if(len > 0)*/
-	else {
+	} else {
 
-#if ESP_TCP_PERF_TX && ESP_TCP_DELAY_INFO
+#if EXAMPLE_ESP_TCP_PERF_TX && EXAMPLE_ESP_TCP_DELAY_INFO
 	    send_fail++;
-#endif /*ESP_TCP_PERF_TX && ESP_TCP_DELAY_INFO*/
-	    
-	    /*Most of the error code will be send window full.
-         *So, for faster sending,don't show error code.
-	     *if it can't work as expectations,unnote the two lines here.
-	     **/
-	    //show_socket_error_code(connect_socket);
-	    //vTaskDelay(500/portTICK_RATE_MS);
-	}
+#endif /*EXAMPLE_ESP_TCP_PERF_TX && EXAMPLE_ESP_TCP_DELAY_INFO*/
+
+	    if (LOG_LOCAL_LEVEL >= ESP_LOG_DEBUG) {
+	    	show_socket_error_reason(connect_socket);
+	    }
+	} /*if(len > 0)*/
     } 
 }
 //receive data
 void recv_data(void *pvParameters)
 {
     int len = 0;
-    char databuff[DEFAULT_PKTSIZE];
+    char databuff[EXAMPLE_DEFAULT_PKTSIZE];
     while (1) {
-	len = recv(connect_socket, databuff, DEFAULT_PKTSIZE, 0);
+	len = recv(connect_socket, databuff, EXAMPLE_DEFAULT_PKTSIZE, 0);
 	if (len > 0) {
 	    total_data += len;
-	}
-	else {
-	    show_socket_error_code(connect_socket);
-	    vTaskDelay(500 / portTICK_RATE_MS);
+	} else {
+            if (LOG_LOCAL_LEVEL >= ESP_LOG_DEBUG) {
+	        show_socket_error_reason(connect_socket);
+            }
+	    vTaskDelay(100 / portTICK_RATE_MS);
 	}
     }
 }
@@ -161,28 +159,28 @@ void recv_data(void *pvParameters)
 //use this esp32 as a tcp server. return ESP_OK:success ESP_FAIL:error
 esp_err_t create_tcp_server()
 {
-    ESP_LOGI(TAG, "server socket....port=%d\n", DEFAULT_PORT);
+    ESP_LOGI(TAG, "server socket....port=%d\n", EXAMPLE_DEFAULT_PORT);
     server_socket = socket(AF_INET, SOCK_STREAM, 0);
     if (server_socket < 0) {
-    	show_socket_error_code(server_socket);
+    	show_socket_error_reason(server_socket);
 	return ESP_FAIL;
     }
     server_addr.sin_family = AF_INET;
-    server_addr.sin_port = htons(DEFAULT_PORT);
+    server_addr.sin_port = htons(EXAMPLE_DEFAULT_PORT);
     server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
     if (bind(server_socket, (struct sockaddr*)&server_addr, sizeof(server_addr)) < 0) {
-    	show_socket_error_code(server_socket);
+    	show_socket_error_reason(server_socket);
 	close(server_socket);
 	return ESP_FAIL;
     }
     if (listen(server_socket, 5) < 0) {
-    	show_socket_error_code(server_socket);
+    	show_socket_error_reason(server_socket);
 	close(server_socket);
 	return ESP_FAIL;
     }
     connect_socket = accept(server_socket, (struct sockaddr*)&client_addr, &socklen);
     if (connect_socket<0) {
-    	show_socket_error_code(connect_socket);
+    	show_socket_error_reason(connect_socket);
 	close(server_socket);
 	return ESP_FAIL;
     }
@@ -194,18 +192,18 @@ esp_err_t create_tcp_server()
 esp_err_t create_tcp_client()
 {
     ESP_LOGI(TAG, "client socket....serverip:port=%s:%d\n", 
-    		DEFAULT_SERVER_IP, DEFAULT_PORT);
+    		EXAMPLE_DEFAULT_SERVER_IP, EXAMPLE_DEFAULT_PORT);
     connect_socket = socket(AF_INET, SOCK_STREAM, 0);
     if (connect_socket < 0) {
-    	show_socket_error_code(connect_socket);
+    	show_socket_error_reason(connect_socket);
 	return ESP_FAIL;
     }
     server_addr.sin_family = AF_INET;
-    server_addr.sin_port = htons(DEFAULT_PORT);
-    server_addr.sin_addr.s_addr = inet_addr(DEFAULT_SERVER_IP);
+    server_addr.sin_port = htons(EXAMPLE_DEFAULT_PORT);
+    server_addr.sin_addr.s_addr = inet_addr(EXAMPLE_DEFAULT_SERVER_IP);
     ESP_LOGI(TAG, "connecting to server...");
     if (connect(connect_socket, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
-    	show_socket_error_code(connect_socket);
+    	show_socket_error_reason(connect_socket);
 	return ESP_FAIL;
     }
     ESP_LOGI(TAG, "connect to server success!");
@@ -215,6 +213,8 @@ esp_err_t create_tcp_client()
 //wifi_init_sta
 void wifi_init_sta()
 {
+    tcp_event_group = xEventGroupCreate();
+
     tcpip_adapter_init();
     ESP_ERROR_CHECK(esp_event_loop_init(event_handler, NULL) );
 
@@ -222,8 +222,8 @@ void wifi_init_sta()
     ESP_ERROR_CHECK(esp_wifi_init(&cfg));
     wifi_config_t wifi_config = {
         .sta = {
-            .ssid = DEFAULT_SSID,
-            .password = DEFAULT_PWD
+            .ssid = EXAMPLE_DEFAULT_SSID,
+            .password = EXAMPLE_DEFAULT_PWD
         },
     };
 
@@ -233,11 +233,13 @@ void wifi_init_sta()
 
     ESP_LOGI(TAG, "wifi_init_sta finished.");
     ESP_LOGI(TAG, "connect to ap SSID:%s password:%s \n",
-	    DEFAULT_SSID,DEFAULT_PWD);
+	    EXAMPLE_DEFAULT_SSID,EXAMPLE_DEFAULT_PWD);
 }
 //wifi_init_softap
 void wifi_init_softap()
 {
+    tcp_event_group = xEventGroupCreate();
+
     tcpip_adapter_init();
     ESP_ERROR_CHECK(esp_event_loop_init(event_handler, NULL));
 
@@ -245,14 +247,14 @@ void wifi_init_softap()
     ESP_ERROR_CHECK(esp_wifi_init(&cfg));
     wifi_config_t wifi_config = {
         .ap = {
-            .ssid = DEFAULT_SSID,
+            .ssid = EXAMPLE_DEFAULT_SSID,
             .ssid_len = 0,
-            .max_connection=MAX_STA_CONN,
-            .password = DEFAULT_PWD,
+            .max_connection=EXAMPLE_MAX_STA_CONN,
+            .password = EXAMPLE_DEFAULT_PWD,
             .authmode = WIFI_AUTH_WPA_WPA2_PSK
         },
     };
-    if (strlen(DEFAULT_PWD) ==0) {
+    if (strlen(EXAMPLE_DEFAULT_PWD) ==0) {
 	wifi_config.ap.authmode = WIFI_AUTH_OPEN;
     }
 
@@ -261,71 +263,48 @@ void wifi_init_softap()
     ESP_ERROR_CHECK(esp_wifi_start());
 
     ESP_LOGI(TAG, "wifi_init_softap finished.SSID:%s password:%s \n",
-    	    DEFAULT_SSID, DEFAULT_PWD);
+    	    EXAMPLE_DEFAULT_SSID, EXAMPLE_DEFAULT_PWD);
 }
 
 
 
 
-char* tcpip_get_reason(int err)
-{
-    switch (err) {
-	case 0:
-	    return "reason: other reason";
-	case ENOMEM:
-	    return "reason: out of memory";
-	case ENOBUFS:
-	    return "reason: buffer error";
-	case EWOULDBLOCK:
-	    return "reason: timeout, try again";
-	case EHOSTUNREACH:
-	    return "reason: routing problem";
-	case EINPROGRESS:
-	    return "reason: operation in progress";
-	case EINVAL:
-	    return "reason: invalid value";
-	case EADDRINUSE:
-	    return "reason: address in use";
-	case EALREADY:
-	    return "reason: conn already connected";
-	case EISCONN:
-	    return "reason: conn already established";
-	case ECONNABORTED:
-	    return "reason: connection aborted";
-	case ECONNRESET:
-	    return "reason: connection is reset";
-	case ENOTCONN:
-	    return "reason: connection closed";
-	case EIO:
-	    return "reason: invalid argument";
-	case -1:
-	    return "reason: low level netif error";
-	default:
-	    return "reason not found";
-    }
-}
-
-int show_socket_error_code(int socket)
+int get_socket_error_code(int socket)
 {
     int result;
     u32_t optlen = sizeof(int);
-    getsockopt(socket, SOL_SOCKET, SO_ERROR, &result, &optlen);
-    ESP_LOGI(TAG, "socket error %d reason: %s", result, tcpip_get_reason(result));
+    if(getsockopt(socket, SOL_SOCKET, SO_ERROR, &result, &optlen) == -1) {
+	ESP_LOGE(TAG, "getsockopt failed");
+	return -1;
+    }
     return result;
 }
 
-int check_socket_error_code()
+int show_socket_error_reason(int socket)
+{
+    int err = get_socket_error_code(socket);
+    ESP_LOGW(TAG, "socket error %d %s", err, strerror(err));
+    return err;
+}
+
+int check_working_socket()
 {
     int ret;
-#if ESP_TCP_MODE_SERVER
-    ESP_LOGI(TAG, "check server_socket");
-    ret = show_socket_error_code(server_socket);
+#if EXAMPLE_ESP_TCP_MODE_SERVER
+    ESP_LOGD(TAG, "check server_socket");
+    ret = get_socket_error_code(server_socket);
+    if(ret != 0) {
+	ESP_LOGW(TAG, "server socket error %d %s", ret, strerror(ret));
+    }
     if(ret == ECONNRESET)
 	return ret;
 #endif
-    ESP_LOGI(TAG, "check connect_socket");
-    ret = show_socket_error_code(connect_socket);
-    if(ret == ECONNRESET)
+    ESP_LOGD(TAG, "check connect_socket");
+    ret = get_socket_error_code(connect_socket);
+    if(ret != 0) {
+	ESP_LOGW(TAG, "connect socket error %d %s", ret, strerror(ret));
+    }
+    if(ret != 0)
 	return ret;
     return 0;
 }
diff --git a/examples/performance/tcp_perf/main/tcp_perf.h b/examples/performance/tcp_perf/main/tcp_perf.h
index e29215b5b..2280dc8f4 100644
--- a/examples/performance/tcp_perf/main/tcp_perf.h
+++ b/examples/performance/tcp_perf/main/tcp_perf.h
@@ -1,3 +1,13 @@
+/* tcp_perf Example
+
+   This example code is in the Public Domain (or CC0 licensed, at your option.)
+
+   Unless required by applicable law or agreed to in writing, this
+   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+   CONDITIONS OF ANY KIND, either express or implied.
+*/
+
+
 #ifndef __TCP_PERF_H__
 #define __TCP_PERF_H__
 
@@ -7,33 +17,43 @@
 extern "C" {
 #endif
 
-/*AP info and tcp_server info*/
-#define DEFAULT_SSID CONFIG_TCP_PERF_WIFI_SSID
-#define DEFAULT_PWD CONFIG_TCP_PERF_WIFI_PASSWORD
-#define DEFAULT_PORT CONFIG_TCP_PERF_SERVER_PORT
-#define DEFAULT_SERVER_IP CONFIG_TCP_PERF_SERVER_IP
-#define DEFAULT_PKTSIZE CONFIG_TCP_PERF_PKT_SIZE
-#define MAX_STA_CONN 1 //how many sta can be connected(AP mode)
+
 /*test options*/
-#define ESP_WIFI_MODE_AP CONFIG_TCP_PERF_WIFI_MODE_AP //TRUE:AP FALSE:STA
-#define ESP_TCP_MODE_SERVER CONFIG_TCP_PERF_SERVER //TRUE:server FALSE:client
-#define ESP_TCP_PERF_TX CONFIG_TCP_PERF_TX //TRUE:send FALSE:receive
-#define ESP_TCP_DELAY_INFO CONFIG_TCP_PERF_DELAY_DEBUG //TRUE:show delay time info
+#define EXAMPLE_ESP_WIFI_MODE_AP CONFIG_TCP_PERF_WIFI_MODE_AP //TRUE:AP FALSE:STA
+#define EXAMPLE_ESP_TCP_MODE_SERVER CONFIG_TCP_PERF_SERVER //TRUE:server FALSE:client
+#define EXAMPLE_ESP_TCP_PERF_TX CONFIG_TCP_PERF_TX //TRUE:send FALSE:receive
+#define EXAMPLE_ESP_TCP_DELAY_INFO CONFIG_TCP_PERF_DELAY_DEBUG //TRUE:show delay time info
+
+/*AP info and tcp_server info*/
+#define EXAMPLE_DEFAULT_SSID CONFIG_TCP_PERF_WIFI_SSID
+#define EXAMPLE_DEFAULT_PWD CONFIG_TCP_PERF_WIFI_PASSWORD
+#define EXAMPLE_DEFAULT_PORT CONFIG_TCP_PERF_SERVER_PORT
+#define EXAMPLE_DEFAULT_PKTSIZE CONFIG_TCP_PERF_PKT_SIZE
+#define EXAMPLE_MAX_STA_CONN 1 //how many sta can be connected(AP mode)
+
+#ifdef CONFIG_TCP_PERF_SERVER_IP
+#define EXAMPLE_DEFAULT_SERVER_IP CONFIG_TCP_PERF_SERVER_IP
+#else
+#define EXAMPLE_DEFAULT_SERVER_IP "192.168.4.1"
+#endif /*CONFIG_TCP_PERF_SERVER_IP*/
 
 
-#define PACK_BYTE_IS 97 //'a'
+
+#define EXAMPLE_PACK_BYTE_IS 97 //'a'
 #define TAG "tcp_perf:"
 
+/* FreeRTOS event group to signal when we are connected to wifi*/
+extern EventGroupHandle_t tcp_event_group;
+#define WIFI_CONNECTED_BIT BIT0
 
-extern int connectedflag;
 extern int total_data;
 
-#if ESP_TCP_PERF_TX && ESP_TCP_DELAY_INFO
+#if EXAMPLE_ESP_TCP_PERF_TX && EXAMPLE_ESP_TCP_DELAY_INFO
 extern int total_pack;
 extern int send_success;
 extern int send_fail;
 extern int delay_classify[5];
-#endif/*ESP_TCP_PERF_TX && ESP_TCP_DELAY_INFO*/
+#endif/*EXAMPLE_ESP_TCP_PERF_TX && EXAMPLE_ESP_TCP_DELAY_INFO*/
 
 
 //using esp as station
@@ -54,11 +74,14 @@ void recv_data(void *pvParameters);
 //close all socket
 void close_socket();
 
+//get socket error code. return: error code
+int get_socket_error_code(int socket);
+
 //show socket error code. return: error code
-int show_socket_error_code(int socket);
+int show_socket_error_reason(int socket);
 
 //check working socket
-int check_socket_error_code();
+int check_working_socket();
 
 
 #ifdef __cplusplus
diff --git a/examples/performance/udp_perf/main/Kconfig.projbuild b/examples/performance/udp_perf/main/Kconfig.projbuild
index 72d40cb98..81ab39589 100644
--- a/examples/performance/udp_perf/main/Kconfig.projbuild
+++ b/examples/performance/udp_perf/main/Kconfig.projbuild
@@ -78,34 +78,35 @@ config UDP_PERF_TX
 
 config UDP_PERF_WIFI_SSID
     string "WiFi SSID"
-	default "esp_wifi_test1"
-	help
-	    SSID (network name) for the example to connect to.
+    default "esp_wifi_test1"
+    help
+	SSID (network name) for the example to connect to.
 
 config UDP_PERF_WIFI_PASSWORD
     string "WiFi Password"
-	default "1234567890"
-	help
-	    WiFi password (WPA or WPA2) for the example to use.
+    default "1234567890"
+    help
+	WiFi password (WPA or WPA2) for the example to use.
 		
 config UDP_PERF_SERVER_PORT
     int "UDP server port"
-	default 4567
-	help 
-	    Which will the udp server use.
+    default 4567
+    help
+	Which will the udp server use.
 				
 config UDP_PERF_SERVER_IP
     string "UDP server ip"
-	default "192.168.4.1" 
-	help
-	    IP of UDP server.
+    depends on UDP_PERF_ESP_IS_CLIENT
+    default "192.168.4.1" 
+    help
+	IP of UDP server.
 		
-	    Ignore in UDP server.
+	Ignore in UDP server.
 	
 config UDP_PERF_PKT_SIZE
     int "Size of UDP packet"
-	default 1460
-	help
-	    the data send&recv packet size. 
+    default 1460
+    help
+	the data send&recv packet size. 
 		
 endmenu
diff --git a/examples/performance/udp_perf/main/udp_main.c b/examples/performance/udp_perf/main/udp_main.c
index 60f59e9b3..d4d8b1fa9 100644
--- a/examples/performance/udp_perf/main/udp_main.c
+++ b/examples/performance/udp_perf/main/udp_main.c
@@ -1,3 +1,13 @@
+/* udp_perf Example
+
+   This example code is in the Public Domain (or CC0 licensed, at your option.)
+
+   Unless required by applicable law or agreed to in writing, this
+   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+   CONDITIONS OF ANY KIND, either express or implied.
+*/
+
+
 
 
 /*
@@ -20,8 +30,10 @@ step3:
 */
 
 
+#include <errno.h>
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
+#include "freertos/event_groups.h"
 #include "esp_log.h"
 #include "esp_err.h"
 
@@ -33,26 +45,24 @@ static void udp_conn(void *pvParameters)
 {
     ESP_LOGI(TAG, "task udp_conn start.");
     /*wating for connecting to AP*/
-    do
-    {
-	vTaskDelay(100);
-    }
-    while (!connectedflag);
+    xEventGroupWaitBits(udp_event_group, WIFI_CONNECTED_BIT,false, true, portMAX_DELAY);
     ESP_LOGI(TAG, "sta has connected to ap.");
     
     /*create udp socket*/
     int socket_ret;
     
-#if ESP_UDP_MODE_SERVER
+#if EXAMPLE_ESP_UDP_MODE_SERVER
+    ESP_LOGI(TAG, "create udp server after 3s...");
     vTaskDelay(3000 / portTICK_RATE_MS);
     ESP_LOGI(TAG, "create_udp_server.");
     socket_ret=create_udp_server();
-#else /*ESP_UDP_MODE_SERVER*/
+#else /*EXAMPLE_ESP_UDP_MODE_SERVER*/
+    ESP_LOGI(TAG, "create udp client after 20s...");
     vTaskDelay(20000 / portTICK_RATE_MS);
     ESP_LOGI(TAG, "create_udp_client.");
     socket_ret = create_udp_client();
 #endif
-    if(ESP_FAIL == socket_ret) {
+    if(socket_ret == ESP_FAIL) {
 	ESP_LOGI(TAG, "create udp socket error,stop.");
 	vTaskDelete(NULL);
     }
@@ -61,17 +71,27 @@ static void udp_conn(void *pvParameters)
     TaskHandle_t tx_rx_task;
     xTaskCreate(&send_recv_data, "send_recv_data", 4096, NULL, 4, &tx_rx_task);
 
-    int pps;
+    /*waiting udp connected success*/
+    xEventGroupWaitBits(udp_event_group, UDP_CONNCETED_SUCCESS,false, true, portMAX_DELAY);
+    int bps;
     while (1) {
 	total_data = 0;
 	vTaskDelay(3000 / portTICK_RATE_MS);//every 3s
-	pps = total_data / 3;
+	bps = total_data / 3;
 
-#if ESP_UDP_PERF_TX
-	ESP_LOGI(TAG, "udp send %d byte per sec! total pack: %d \n", pps, success_pack);
+	if (total_data <= 0) {
+	    int err_ret = check_connected_socket();
+	    if (err_ret == -1) {  //-1 reason: low level netif error
+		ESP_LOGW(TAG, "udp send & recv stop.\n");
+		break;
+	    }
+	}
+
+#if EXAMPLE_ESP_UDP_PERF_TX
+	ESP_LOGI(TAG, "udp send %d byte per sec! total pack: %d \n", bps, success_pack);
 #else
-	ESP_LOGI(TAG, "udp recv %d byte per sec! total pack: %d \n", pps, success_pack);
-#endif /*ESP_UDP_PERF_TX*/
+	ESP_LOGI(TAG, "udp recv %d byte per sec! total pack: %d \n", bps, success_pack);
+#endif /*EXAMPLE_ESP_UDP_PERF_TX*/
     }
     close_socket();
     vTaskDelete(tx_rx_task);
@@ -82,11 +102,11 @@ static void udp_conn(void *pvParameters)
 
 void app_main(void)
 {
-#if ESP_WIFI_MODE_AP
-    ESP_LOGI(TAG, "ESP_WIFI_MODE_AP\n");
+#if EXAMPLE_ESP_WIFI_MODE_AP
+    ESP_LOGI(TAG, "EXAMPLE_ESP_WIFI_MODE_AP");
     wifi_init_softap();
-#else /*ESP_WIFI_MODE_AP*/
-    ESP_LOGI(TAG, "ESP_WIFI_MODE_STA\n");
+#else /*EXAMPLE_ESP_WIFI_MODE_AP*/
+    ESP_LOGI(TAG, "ESP_WIFI_MODE_STA");
     wifi_init_sta();
 #endif
     xTaskCreate(&udp_conn, "udp_conn", 4096, NULL, 5, NULL);
diff --git a/examples/performance/udp_perf/main/udp_perf.c b/examples/performance/udp_perf/main/udp_perf.c
index 22a55ad90..694494624 100644
--- a/examples/performance/udp_perf/main/udp_perf.c
+++ b/examples/performance/udp_perf/main/udp_perf.c
@@ -1,21 +1,17 @@
-// Copyright 2013-2016 Espressif Systems (Shanghai) PTE LTD
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+/* udp_perf Example
+
+   This example code is in the Public Domain (or CC0 licensed, at your option.)
+
+   Unless required by applicable law or agreed to in writing, this
+   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+   CONDITIONS OF ANY KIND, either express or implied.
+*/
 
 #include <string.h>
 #include <sys/socket.h>
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
+#include "freertos/event_groups.h"
 #include "esp_wifi.h"
 #include "esp_event_loop.h"
 #include "esp_log.h"
@@ -24,13 +20,15 @@
 #include "udp_perf.h"
 
 
+/* FreeRTOS event group to signal when we are connected to WiFi and ready to start UDP test*/
+EventGroupHandle_t udp_event_group;
+
 
 static int mysocket;
 
 static struct sockaddr_in remote_addr;
 static unsigned int socklen;
 
-int connectedflag = 0;
 int total_data = 0;
 int success_pack = 0;
 
@@ -43,6 +41,7 @@ static esp_err_t event_handler(void *ctx, system_event_t *event)
         break;
     case SYSTEM_EVENT_STA_DISCONNECTED:
         esp_wifi_connect();
+        xEventGroupClearBits(udp_event_group, WIFI_CONNECTED_BIT);
         break;
     case SYSTEM_EVENT_STA_CONNECTED:
         break;
@@ -50,18 +49,19 @@ static esp_err_t event_handler(void *ctx, system_event_t *event)
     	ESP_LOGI(TAG, "event_handler:SYSTEM_EVENT_STA_GOT_IP!");
     	ESP_LOGI(TAG, "got ip:%s\n",
 		ip4addr_ntoa(&event->event_info.got_ip.ip_info.ip));
-        connectedflag=1;
+    	xEventGroupSetBits(udp_event_group, WIFI_CONNECTED_BIT);
         break;
     case SYSTEM_EVENT_AP_STACONNECTED:
     	ESP_LOGI(TAG, "station:"MACSTR" join,AID=%d\n",
 		MAC2STR(event->event_info.sta_connected.mac),
 		event->event_info.sta_connected.aid);
-    	connectedflag=1;
+    	xEventGroupSetBits(udp_event_group, WIFI_CONNECTED_BIT);
     	break;
     case SYSTEM_EVENT_AP_STADISCONNECTED:
     	ESP_LOGI(TAG, "station:"MACSTR"leave,AID=%d\n",
 		MAC2STR(event->event_info.sta_disconnected.mac),
 		event->event_info.sta_disconnected.aid);
+    	xEventGroupClearBits(udp_event_group, WIFI_CONNECTED_BIT);
     	break;
     default:
         break;
@@ -73,6 +73,8 @@ static esp_err_t event_handler(void *ctx, system_event_t *event)
 //wifi_init_sta
 void wifi_init_sta()
 {
+    udp_event_group = xEventGroupCreate();
+    
     tcpip_adapter_init();
     ESP_ERROR_CHECK(esp_event_loop_init(event_handler, NULL) );
 
@@ -80,8 +82,8 @@ void wifi_init_sta()
     ESP_ERROR_CHECK(esp_wifi_init(&cfg));
     wifi_config_t wifi_config = {
         .sta = {
-            .ssid = DEFAULT_SSID,
-            .password = DEFAULT_PWD
+            .ssid = EXAMPLE_DEFAULT_SSID,
+            .password = EXAMPLE_DEFAULT_PWD
         },
     };
 
@@ -91,11 +93,13 @@ void wifi_init_sta()
 
     ESP_LOGI(TAG, "wifi_init_sta finished.");
     ESP_LOGI(TAG, "connect to ap SSID:%s password:%s \n",
-	    DEFAULT_SSID,DEFAULT_PWD);
+	    EXAMPLE_DEFAULT_SSID,EXAMPLE_DEFAULT_PWD);
 }
 //wifi_init_softap
 void wifi_init_softap()
 {
+    udp_event_group = xEventGroupCreate();
+    
     tcpip_adapter_init();
     ESP_ERROR_CHECK(esp_event_loop_init(event_handler, NULL));
 
@@ -103,14 +107,14 @@ void wifi_init_softap()
     ESP_ERROR_CHECK(esp_wifi_init(&cfg));
     wifi_config_t wifi_config = {
         .ap = {
-            .ssid = DEFAULT_SSID,
+            .ssid = EXAMPLE_DEFAULT_SSID,
             .ssid_len=0,
-            .max_connection=MAX_STA_CONN,
-            .password = DEFAULT_PWD,
+            .max_connection=EXAMPLE_MAX_STA_CONN,
+            .password = EXAMPLE_DEFAULT_PWD,
             .authmode=WIFI_AUTH_WPA_WPA2_PSK
         },
     };
-    if (strlen(DEFAULT_PWD) ==0) {
+    if (strlen(EXAMPLE_DEFAULT_PWD) ==0) {
 	wifi_config.ap.authmode = WIFI_AUTH_OPEN;
     }
 
@@ -119,24 +123,24 @@ void wifi_init_softap()
     ESP_ERROR_CHECK(esp_wifi_start());
 
     ESP_LOGI(TAG, "wifi_init_softap finished.SSID:%s password:%s \n",
-    	    DEFAULT_SSID, DEFAULT_PWD);
+    	    EXAMPLE_DEFAULT_SSID, EXAMPLE_DEFAULT_PWD);
 }
 
 //create a udp server socket. return ESP_OK:success ESP_FAIL:error
 esp_err_t create_udp_server()
 {
-    ESP_LOGI(TAG, "create_udp_server()");
+    ESP_LOGI(TAG, "create_udp_server() port:%d", EXAMPLE_DEFAULT_PORT);
     mysocket = socket(AF_INET, SOCK_DGRAM, 0);
     if (mysocket < 0) {
-	show_socket_error_code(mysocket);
+    	show_socket_error_reason(mysocket);
 	return ESP_FAIL;
     }
     struct sockaddr_in server_addr;
     server_addr.sin_family = AF_INET;
-    server_addr.sin_port = htons(DEFAULT_PORT);
+    server_addr.sin_port = htons(EXAMPLE_DEFAULT_PORT);
     server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
     if (bind(mysocket, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
-	show_socket_error_code(mysocket);
+    	show_socket_error_reason(mysocket);
 	close(mysocket);
 	return ESP_FAIL;
     }
@@ -147,15 +151,17 @@ esp_err_t create_udp_server()
 esp_err_t create_udp_client()
 {
     ESP_LOGI(TAG, "create_udp_client()");
+    ESP_LOGI(TAG, "connecting to %s:%d",
+	    EXAMPLE_DEFAULT_SERVER_IP, EXAMPLE_DEFAULT_PORT);
     mysocket = socket(AF_INET, SOCK_DGRAM, 0);
     if (mysocket < 0) {
-	show_socket_error_code(mysocket);
+    	show_socket_error_reason(mysocket);
 	return ESP_FAIL;
     }
     /*for client remote_addr is also server_addr*/
     remote_addr.sin_family = AF_INET;
-    remote_addr.sin_port = htons(DEFAULT_PORT);
-    remote_addr.sin_addr.s_addr = inet_addr(DEFAULT_SERVER_IP);
+    remote_addr.sin_port = htons(EXAMPLE_DEFAULT_PORT);
+    remote_addr.sin_addr.s_addr = inet_addr(EXAMPLE_DEFAULT_SERVER_IP);
 
     return ESP_OK;
 }
@@ -167,102 +173,79 @@ void send_recv_data(void *pvParameters)
     ESP_LOGI(TAG, "task send_recv_data start!\n");
     
     int len;
-    char databuff[DEFAULT_PKTSIZE];
+    char databuff[EXAMPLE_DEFAULT_PKTSIZE];
     
     /*send&receive first packet*/
     socklen = sizeof(remote_addr);
-    memset(databuff, PACK_BYTE_IS, DEFAULT_PKTSIZE);
-#if ESP_UDP_MODE_SERVER
+    memset(databuff, EXAMPLE_PACK_BYTE_IS, EXAMPLE_DEFAULT_PKTSIZE);
+#if EXAMPLE_ESP_UDP_MODE_SERVER
     ESP_LOGI(TAG, "first recvfrom:");
-    len = recvfrom(mysocket, databuff, DEFAULT_PKTSIZE, 0, (struct sockaddr *)&remote_addr, &socklen);
+    len = recvfrom(mysocket, databuff, EXAMPLE_DEFAULT_PKTSIZE, 0, (struct sockaddr *)&remote_addr, &socklen);
 #else
     ESP_LOGI(TAG, "first sendto:");
-    len = sendto(mysocket, databuff, DEFAULT_PKTSIZE, 0, (struct sockaddr *)&remote_addr, sizeof(remote_addr));
+    len = sendto(mysocket, databuff, EXAMPLE_DEFAULT_PKTSIZE, 0, (struct sockaddr *)&remote_addr, sizeof(remote_addr));
 #endif
     
     if (len > 0) {
 	ESP_LOGI(TAG, "transfer data with %s:%u\n",
 		inet_ntoa(remote_addr.sin_addr), ntohs(remote_addr.sin_port));
+	xEventGroupSetBits(udp_event_group, UDP_CONNCETED_SUCCESS);
     } else {
-	show_socket_error_code(mysocket);
+    	show_socket_error_reason(mysocket);
 	close(mysocket);
 	vTaskDelete(NULL);
-    }
+    } /*if (len > 0)*/
     
-#if ESP_UDP_PERF_TX
+#if EXAMPLE_ESP_UDP_PERF_TX
     vTaskDelay(500 / portTICK_RATE_MS);
 #endif
     ESP_LOGI(TAG, "start count!\n");
-    while(1)
-    {
-	/*you can add delay time for fixed-frequency*/
-	//vTaskDelay(5 / portTICK_RATE_MS);
-#if ESP_UDP_PERF_TX
-	len = sendto(mysocket, databuff, DEFAULT_PKTSIZE, 0, (struct sockaddr *)&remote_addr, sizeof(remote_addr));
+    while(1) {
+#if EXAMPLE_ESP_UDP_PERF_TX
+	len = sendto(mysocket, databuff, EXAMPLE_DEFAULT_PKTSIZE, 0, (struct sockaddr *)&remote_addr, sizeof(remote_addr));
 #else
-	len = recvfrom(mysocket, databuff, DEFAULT_PKTSIZE, 0, (struct sockaddr *)&remote_addr, &socklen);
+	len = recvfrom(mysocket, databuff, EXAMPLE_DEFAULT_PKTSIZE, 0, (struct sockaddr *)&remote_addr, &socklen);
 #endif
 	if (len > 0) {
 	    total_data += len;
 	    success_pack++;
 	} else {
-	    //show_socket_error_code(mysocket);
-	    /*you'd better turn off watch dog in menuconfig
-	     *Component config->ESP32-specific->Task watchdog.
-	     **/
-	    //vTaskDelay(1/portTICK_RATE_MS);
-	}
-    }
+	    if (LOG_LOCAL_LEVEL >= ESP_LOG_DEBUG) {
+		show_socket_error_reason(mysocket);
+	    }
+	} /*if (len > 0)*/
+    } /*while(1)*/
 }
 
 
-char* tcpip_get_reason(int err)
-{
-    switch (err) {
-    case 0:
-        return "reason: other reason";
-    case ENOMEM:
-        return "reason: out of memory";
-    case ENOBUFS:
-        return "reason: buffer error";
-    case EWOULDBLOCK:
-        return "reason: timeout, try again";
-    case EHOSTUNREACH:
-        return "reason: routing problem";
-    case EINPROGRESS:
-        return "reason: operation in progress";
-    case EINVAL:
-        return "reason: invalid value";
-    case EADDRINUSE:
-        return "reason: address in use";
-    case EALREADY:
-        return "reason: conn already connected";
-    case EISCONN:
-        return "reason: conn already established";
-    case ECONNABORTED:
-        return "reason: connection aborted";
-    case ECONNRESET:
-        return "reason: connection is reset";
-    case ENOTCONN:
-        return "reason: connection closed";
-    case EIO:
-        return "reason: invalid argument";
-    case -1:
-        return "reason: low level netif error";
-    default:
-        return "reason not found";
-    }
-}
-
-int show_socket_error_code(int socket)
+int get_socket_error_code(int socket)
 {
     int result;
     u32_t optlen = sizeof(int);
-    getsockopt(socket, SOL_SOCKET, SO_ERROR, &result, &optlen);
-    ESP_LOGI(TAG, "socket error %d reason: %s", result, tcpip_get_reason(result));
+    if(getsockopt(socket, SOL_SOCKET, SO_ERROR, &result, &optlen) == -1) {
+	ESP_LOGE(TAG, "getsockopt failed");
+	return -1;
+    }
     return result;
 }
 
+int show_socket_error_reason(int socket)
+{
+    int err = get_socket_error_code(socket);
+    ESP_LOGW(TAG, "socket error %d %s", err, strerror(err));
+    return err;
+}
+
+int check_connected_socket()
+{
+    int ret;
+    ESP_LOGD(TAG, "check connect_socket");
+    ret = get_socket_error_code(mysocket);
+    if(ret != 0) {
+    	ESP_LOGW(TAG, "socket error %d %s", ret, strerror(ret));
+    }
+    return ret;
+}
 
 void close_socket()
 {
diff --git a/examples/performance/udp_perf/main/udp_perf.h b/examples/performance/udp_perf/main/udp_perf.h
index 0f8221559..11c1c512d 100644
--- a/examples/performance/udp_perf/main/udp_perf.h
+++ b/examples/performance/udp_perf/main/udp_perf.h
@@ -1,3 +1,13 @@
+/* udp_perf Example
+
+   This example code is in the Public Domain (or CC0 licensed, at your option.)
+
+   Unless required by applicable law or agreed to in writing, this
+   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+   CONDITIONS OF ANY KIND, either express or implied.
+*/
+
+
 #ifndef __UDP_PERF_H__
 #define __UDP_PERF_H__
 
@@ -7,23 +17,33 @@
 extern "C" {
 #endif
 
-/*AP info and tcp_server info*/
-#define DEFAULT_SSID CONFIG_UDP_PERF_WIFI_SSID
-#define DEFAULT_PWD CONFIG_UDP_PERF_WIFI_PASSWORD
-#define DEFAULT_PORT CONFIG_UDP_PERF_SERVER_PORT
-#define DEFAULT_SERVER_IP CONFIG_UDP_PERF_SERVER_IP
-#define DEFAULT_PKTSIZE CONFIG_UDP_PERF_PKT_SIZE
-#define MAX_STA_CONN 1 //how many sta can be connected(AP mode)
+
 /*test options*/
-#define ESP_WIFI_MODE_AP CONFIG_UDP_PERF_WIFI_MODE_AP //TRUE:AP FALSE:STA
-#define ESP_UDP_MODE_SERVER CONFIG_UDP_PERF_SERVER //TRUE:server FALSE:client
-#define ESP_UDP_PERF_TX CONFIG_UDP_PERF_TX //TRUE:send FALSE:receive
-#define PACK_BYTE_IS 97 //'a'
+#define EXAMPLE_ESP_WIFI_MODE_AP CONFIG_UDP_PERF_WIFI_MODE_AP //TRUE:AP FALSE:STA
+#define EXAMPLE_ESP_UDP_MODE_SERVER CONFIG_UDP_PERF_SERVER //TRUE:server FALSE:client
+#define EXAMPLE_ESP_UDP_PERF_TX CONFIG_UDP_PERF_TX //TRUE:send FALSE:receive
+#define EXAMPLE_PACK_BYTE_IS 97 //'a'
+/*AP info and tcp_server info*/
+#define EXAMPLE_DEFAULT_SSID CONFIG_UDP_PERF_WIFI_SSID
+#define EXAMPLE_DEFAULT_PWD CONFIG_UDP_PERF_WIFI_PASSWORD
+#define EXAMPLE_DEFAULT_PORT CONFIG_UDP_PERF_SERVER_PORT
+#define EXAMPLE_DEFAULT_PKTSIZE CONFIG_UDP_PERF_PKT_SIZE
+#define EXAMPLE_MAX_STA_CONN 1 //how many sta can be connected(AP mode)
+
+#ifdef CONFIG_UDP_PERF_SERVER_IP
+#define EXAMPLE_DEFAULT_SERVER_IP CONFIG_UDP_PERF_SERVER_IP
+#else
+#define EXAMPLE_DEFAULT_SERVER_IP "192.168.4.1"
+#endif /*CONFIG_UDP_PERF_SERVER_IP*/
+
 
 #define TAG "udp_perf:"
 
+/* FreeRTOS event group to signal when we are connected to WiFi and ready to start UDP test*/
+extern EventGroupHandle_t udp_event_group;
+#define WIFI_CONNECTED_BIT BIT0
+#define UDP_CONNCETED_SUCCESS BIT1
 
-extern int connectedflag;
 extern int total_data;
 extern int success_pack;
 
@@ -41,8 +61,14 @@ esp_err_t create_udp_client();
 //send or recv data task
 void send_recv_data(void *pvParameters);
 
+//get socket error code. return: error code
+int get_socket_error_code(int socket);
+
 //show socket error code. return: error code
-int show_socket_error_code(int socket);
+int show_socket_error_reason(int socket);
+
+//check connected socket. return: error code
+int check_connected_socket();
 
 //close all socket
 void close_socket();