"If the UDP buffer is full then "sendto" will block".So why the "sendto" return fail and fail reason is ENOMEM.By default, a UDP socket is blocking and if the UDP buffer is full then "sendto" will block
I tried fcntl(fd, F_SETFL, 0).But "sendto" still return fails and fail reason is ENOMEM.If you need to make the socket blocking again then you can call fcntl(fd, F_SETFL, 0)
Code: Select all
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/event_groups.h"
#include "esp_system.h"
#include "esp_wifi.h"
#include "esp_event_loop.h"
#include "esp_log.h"
#include "nvs_flash.h"
#include "esp_wifi_types.h"
#include "esp_task_wdt.h"
#include "lwip/err.h"
#include "lwip/sockets.h"
#include "lwip/sys.h"
#include "lwip/netdb.h"
#include "lwip/dns.h"
#include "lwip/api.h"
#include "lwip/netbuf.h"
#define TEST_BUFFER_ADDRESS 0x3f400000
#define EXAMPLE_WIFI_SSID "jason888"
#define EXAMPLE_WIFI_PASS "wise6688"
#define REMOTE_PORT 1112
/* FreeRTOS event group to signal when we are connected & ready to make a request */
static EventGroupHandle_t wifi_event_group;
/* The event group allows multiple bits for each event,
but we only care about one event - are we connected
to the AP with an IP? */
const int CONNECTED_BIT = BIT0;
static const char *TAG = "Log_Test";
#define SEND_BUF_LEN 480
#define SEND_START_LEN 5
#define SEND_END_LEN 3
const unsigned char start[5]="start";
const unsigned char end[3]="end";
unsigned char test_buffer[1440];
static void udp_thread(void *p)
{
int i = 0;
int ret=0;
int sock;
struct sockaddr_in toAddr;
LWIP_UNUSED_ARG(p);
sock = socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP);
if(sock < 0)
{
ESP_LOGI(TAG, "socket err");
}
fcntl(sock,F_SETFL,0);
memset(&toAddr,0,sizeof(toAddr));
toAddr.sin_family=AF_INET;
toAddr.sin_addr.s_addr=inet_addr("192.168.43.1");
toAddr.sin_port = htons(REMOTE_PORT);
printf("test_buffer is %p",test_buffer);
int fail_count=0;
while(1) {
xEventGroupWaitBits(wifi_event_group, CONNECTED_BIT, false, true, portMAX_DELAY);
sendto(sock,start,SEND_START_LEN,0,(struct sockaddr*)&toAddr,sizeof(toAddr));
for(i=0; i<80; i++)
{
vTaskDelay(1/portTICK_RATE_MS);
ret=sendto(sock,test_buffer,1440,0,(struct sockaddr*)&toAddr,sizeof(toAddr));
if(ret<0)
{
perror("fail reason is:\n");
fail_count++;
}
}
vTaskDelay(400/portTICK_RATE_MS);
printf("fail_count=%d\n",fail_count);
fail_count=0;
sendto(sock,end,SEND_END_LEN,0,(struct sockaddr*)&toAddr,sizeof(toAddr));
}
close(sock);
vTaskDelete(NULL);
}
static void udp_client_init(void)
{
int ret;
ret = xTaskCreate(&udp_thread, "udp_client_task", 2048, NULL, 5, NULL);
if(ret != pdPASS)
{
ESP_LOGI(TAG, "create thread udp_client_task failed");
}
}
static esp_err_t event_handler(void *ctx, system_event_t *event)
{
switch(event->event_id) {
case SYSTEM_EVENT_STA_START:
esp_wifi_connect();
break;
case SYSTEM_EVENT_STA_GOT_IP:
xEventGroupSetBits(wifi_event_group, CONNECTED_BIT);
udp_client_init();
break;
case SYSTEM_EVENT_STA_DISCONNECTED:
esp_wifi_connect();
xEventGroupClearBits(wifi_event_group, CONNECTED_BIT);
break;
default:
break;
}
return ESP_OK;
}
static void initialise_wifi(void)
{
tcpip_adapter_init();
wifi_event_group = xEventGroupCreate();
ESP_ERROR_CHECK( esp_event_loop_init(event_handler, NULL) );
wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
ESP_ERROR_CHECK( esp_wifi_init(&cfg) );
wifi_config_t wifi_config = {
.sta = {
.ssid = EXAMPLE_WIFI_SSID,
.password = EXAMPLE_WIFI_PASS,
},
};
ESP_LOGI(TAG, "Setting WiFi configuration SSID %s...", wifi_config.sta.ssid);
ESP_ERROR_CHECK( esp_wifi_set_mode(WIFI_MODE_STA) );
ESP_ERROR_CHECK( esp_wifi_set_config(WIFI_IF_STA, &wifi_config) );
ESP_ERROR_CHECK( esp_wifi_start());
esp_wifi_set_ps(WIFI_PS_MODEM);
}
void app_main()
{
nvs_flash_init();
initialise_wifi();
}