esp32 rest chuncked response - rest

Question

Im trying to know the real wifi speed capabilities of the esp32, and so i created a simple routine using a common library
void speedTest(AsyncWebServerRequest *request)
{
static uint8_t data[1024] = {0};
static uint32_t dataLen = 1*1024*1024;
memcpy(data, "ciao", 4);
AsyncWebServerResponse *response = request->beginChunkedResponse("application/octet-stream", [](uint8_t *buffer, size_t maxLen, size_t index) -> size_t {
size_t len = (dataLen>maxLen)?maxLen:dataLen;
if (len>0)
{
memcpy(buffer, data, len);
dataLen -= len;
index += len;
}
return len;
});
response->setContentLength(dataLen);
request->send(response);
}
but when i make the GET request, the board reset itself and in serial monitor i see the following log:
rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:2
load:0x3fff0018,len:4
load:0x3fff001c,len:1044
load:0x40078000,len:10124
load:0x40080400,len:5828
entry 0x400806a8
E (17770) task_wdt: Task watchdog got triggered. The following tasks did not reset the watchdog in time:
E (17770) task_wdt: - async_tcp (CPU 0/1)
E (17770) task_wdt: Tasks currently running:
E (17770) task_wdt: CPU 0: IDLE0
E (17770) task_wdt: CPU 1: loopTask
E (17770) task_wdt: Aborting.
abort() was called at PC 0x40131b44 on core 0
I also have tried to reduce the file size and the download goes fine, but for my purpose is useless.
Someone has already meet and solved this problem ? im not really a lambda lover, alternately a different library more customizable, if is possible I would not like to reimplement all the http protocol over socket.
thanks in adavance for the help.
comeplete code:
#include <Arduino.h>
#ifdef ESP32
#include <WiFi.h>
#include <AsyncTCP.h>
#elif defined(ESP8266)
#include <ESP8266WiFi.h>
#include <ESPAsyncTCP.h>
#endif
#include <ESPAsyncWebServer.h>
IPAddress local_ip(192,168,1,1);
IPAddress gateway(192,168,1,1);
IPAddress subnet(255,255,255,0);
AsyncWebServer server(80);
const char* ssid = "testSpeed";
const char* psw = "12345678";
void notFound(AsyncWebServerRequest *request)
{
request->send(404, "text/plain", "Not found");
}
void speedTest(AsyncWebServerRequest *request)
{
#if 1
static uint8_t data[1024] = {0};
static uint32_t dataLen = 1*1024*1024;
memcpy(data, "ciao", 4);
AsyncWebServerResponse *response = request->beginChunkedResponse("application/octet-stream", [](uint8_t *buffer, size_t maxLen, size_t index) -> size_t {
size_t len = (dataLen>maxLen)?maxLen:dataLen;
if (len>0)
{
memcpy(buffer, data, len);
dataLen -= len;
index += len;
}
return len;
});
response->setContentLength(dataLen);
request->send(response);
#endif
}
void setup() {
Serial.begin(115200);
WiFi.mode(WIFI_AP);
WiFi.softAP(ssid, psw);
WiFi.softAPConfig(local_ip, gateway, subnet);
server.on("/stream", HTTP_GET, speedTest);
server.onNotFound(notFound);
server.begin();
}
void loop() {
}

Answer 1

Looks like the implementation of AsyncWebServer is not meant for long-running transactions, as it never resets the task watchdog. As a workaround you can increase the watchdog timeout to its maximum limit of 60 s or disable it entirely. It's controlled by the following options in sdkconfig:
CONFIG_ESP_TASK_WDT=y # Task Watchdog is enabled
CONFIG_ESP_TASK_WDT_PANIC=y # Panic (reset) is invoked on timeout
CONFIG_ESP_TASK_WDT_TIMEOUT_S=30 # Timeout in seconds
The normal way to change those is to run idf.py menuconfig (where they appear under "Component config", "Common ESP-related") but you can just update the file "sdkconfig" directly.
Undo those changes after you're finished with your experiments, it's usually a good idea to keep the Task Watchdog enabled.