FreeRTOS Task notification crashing esp32.

[Gardin]

Hello all,

I'm currently studying Tasks notifications (FreeRTOS) with the esp32, in some tests like using it as a binary semaphore I had no trouble. But when I started to try passing data around using xTaskNotify() and xTaskNotifyWait() the esp32 started to crash when printing the data

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Core  1 panic'ed (LoadProhibited). Exception was unhandled

. For some reason I'm getting an invalid memory location out of the xTaskNotifyWait().
At first, I thought it was because an untested FreeRTOS API, but it appears that this API is currently supported.

Is that a bug or I'm missing something?

I'm using esp-idf version v4.1-dev-2055-gf5b82c5b1-dirty

Regards,

Gardin.

[mikemoy]

Probably be better to answer the question if you posted your code.

[Gardin]

Yes, sorry about that.

Here is the code:

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void task1(void *pvParameters);
void task2(void *pvParameters);

static TaskHandle_t task1_handle;
static TaskHandle_t task2_handle = NULL;



void app_main(void)
{
    xTaskCreatePinnedToCore(task1, "Task1", 1024, NULL, 1, &task1_handle, 1);
    xTaskCreatePinnedToCore(task2, "Task2", 1024, NULL, 1, &task2_handle, 1);
}


void task1(void *pvParameters)
{
    const TickType_t block_time = pdMS_TO_TICKS(10);
    uint32_t ulNotifiedValue = 0;
    uint32_t teste = 0;
    BaseType_t xResult;
    for(;;)
    {
        xResult = xTaskNotifyWait(0X00, 0x00, &ulNotifiedValue,  block_time);
        if(xResult == pdPASS)
        {
            printf("A task2 ja roudou %zu vezes. E eu sou a task1\n", ulNotifiedValue);
        }

        vTaskDelay(pdMS_TO_TICKS(250));
    }
}


void task2(void *pvParameters)
{
    static uint32_t counter = 0;
    static uint32_t counter2 = 0;
    for(;;)
    {
        counter ++;
        counter2 ++;
        if(counter == 5)
        {
            xTaskNotify(task1_handle, counter2, eSetValueWithoutOverwrite);
            printf("oi sou a task2\n");
            counter = 0;
        }
        vTaskDelay(pdMS_TO_TICKS(1000));
    }
}

It works untill I call

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xTaskNotify(task1_handle, counter2, eSetValueWithoutOverwrite);

after that task1 prints the received value once and crashes.

[mikemoy]

The first thing that jumps out at me is that your stack allotment is to low for using a printf.
Kick them up to at least 2048 and try it.

xTaskCreatePinnedToCore(task1, "Task1", 2048, NULL, 1, &task1_handle, 1);
xTaskCreatePinnedToCore(task2, "Task2", 2048, NULL, 1, &task2_handle, 1);

[Gardin]

Oh boy, how did I missed that!?

It's working now thanks a lot!

[AG1702]

Help with this, please. It crashes.

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#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_system.h"
#include "driver/gpio.h"

TaskHandle_t myTask1Handle = NULL;
TaskHandle_t myTask2Handle = NULL;

void myTask1(void *pvParameter)
{
	while(1)
	{
	    xTaskNotifyGive(myTask2Handle);
            vTaskDelay(1000);
	}
}

void myTask2(void *pvParameter)
{
    int not_value = 0;
    while(1) 
    {
        not_value = ulTaskNotifyTake( pdTRUE, (TickType_t) portMAX_DELAY );
        if(not_value > 0)
        {
            printf("notification received: %d\r\n", not_value);
        }
    }
}

void app_main()
{
    xTaskCreate(&myTask1, "myTask1", 2048, NULL, 1, &myTask1Handle);
    xTaskCreate(&myTask2, "myTask2", 2048, NULL, 1, &myTask2Handle);
}

[ESP_Sprite]

What if in your code xTaskNotifyGive is called in task1 while the xTaskCreate of task 2 is not finished yet?