/* FreeRTOS Real Time Stats 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 <stdio.h>
#include <stdlib.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/semphr.h"
#include "esp_err.h"
#define NUM_OF_SPIN_TASKS 6
#define SPIN_ITER 500000 //Actual CPU cycles used will depend on compiler optimization
#define SPIN_TASK_PRIO 2
#define STATS_TASK_PRIO 3
#define STATS_TICKS pdMS_TO_TICKS(1000)
#define ARRAY_SIZE_OFFSET 5 //Increase this if print_real_time_stats returns ESP_ERR_INVALID_SIZE
static char task_names[NUM_OF_SPIN_TASKS][configMAX_TASK_NAME_LEN];
static SemaphoreHandle_t sync_spin_task;
static SemaphoreHandle_t sync_stats_task;
/**
* @brief Function to print the CPU usage of tasks over a given duration.
*
* This function will measure and print the CPU usage of tasks over a specified
* number of ticks (i.e. real time stats). This is implemented by simply calling
* uxTaskGetSystemState() twice separated by a delay, then calculating the
* differences of task run times before and after the delay.
*
* @note If any tasks are added or removed during the delay, the stats of
* those tasks will not be printed.
* @note This function should be called from a high priority task to minimize
* inaccuracies with delays.
* @note When running in dual core mode, each core will correspond to 50% of
* the run time.
*
* @param xTicksToWait Period of stats measurement
*
* @return
* - ESP_OK Success
* - ESP_ERR_NO_MEM Insufficient memory to allocated internal arrays
* - ESP_ERR_INVALID_SIZE Insufficient array size for uxTaskGetSystemState. Trying increasing ARRAY_SIZE_OFFSET
* - ESP_ERR_INVALID_STATE Delay duration too short
*/
static esp_err_t print_real_time_stats(TickType_t xTicksToWait)
{
TaskStatus_t *start_array = NULL, *end_array = NULL;
UBaseType_t start_array_size, end_array_size;
uint32_t start_run_time, end_run_time;
esp_err_t ret;
//Allocate array to store current task states
start_array_size = uxTaskGetNumberOfTasks() + ARRAY_SIZE_OFFSET;
start_array
= malloc(sizeof(TaskStatus_t
) * start_array_size
); if (start_array == NULL) {
ret = ESP_ERR_NO_MEM;
}
//Get current task states
start_array_size = uxTaskGetSystemState(start_array, start_array_size, &start_run_time);
if (start_array_size == 0) {
ret = ESP_ERR_INVALID_SIZE;
}
vTaskDelay(xTicksToWait);
//Allocate array to store tasks states post delay
end_array_size = uxTaskGetNumberOfTasks() + ARRAY_SIZE_OFFSET;
end_array
= malloc(sizeof(TaskStatus_t
) * end_array_size
); if (end_array == NULL) {
ret = ESP_ERR_NO_MEM;
}
//Get post delay task states
end_array_size = uxTaskGetSystemState(end_array, end_array_size, &end_run_time);
if (end_array_size == 0) {
ret = ESP_ERR_INVALID_SIZE;
}
//Calculate total_elapsed_time in units of run time stats clock period.
uint32_t total_elapsed_time = (end_run_time - start_run_time);
if (total_elapsed_time == 0) {
ret = ESP_ERR_INVALID_STATE;
}
printf("| Task | Run Time | Percentage\n"); //Match each task in start_array to those in the end_array
for (int i = 0; i < start_array_size; i++) {
int k = -1;
for (int j = 0; j < end_array_size; j++) {
if (start_array[i].xHandle == end_array[j].xHandle) {
k = j;
//Mark that task have been matched by overwriting their handles
start_array[i].xHandle = NULL;
end_array[j].xHandle = NULL;
break;
}
}
//Check if matching task found
if (k >= 0) {
uint32_t task_elapsed_time = end_array[k].ulRunTimeCounter - start_array[i].ulRunTimeCounter;
uint32_t percentage_time = (task_elapsed_time * 100UL) / (total_elapsed_time * portNUM_PROCESSORS);
printf("| %s | %d | %d%%\n", start_array
[i
].
pcTaskName, task_elapsed_time
, percentage_time
); }
}
//Print unmatched tasks
for (int i = 0; i < start_array_size; i++) {
if (start_array[i].xHandle != NULL) {
printf("| %s | Deleted\n", start_array
[i
].
pcTaskName); }
}
for (int i = 0; i < end_array_size; i++) {
if (end_array[i].xHandle != NULL) {
printf("| %s | Created\n", end_array
[i
].
pcTaskName); }
}
ret = ESP_OK;
exit: //Common return path return ret;
}
static void spin_task(void *arg)
{
xSemaphoreTake(sync_spin_task, portMAX_DELAY);
while (1) {
//Consume CPU cycles
for (int i = 0; i < SPIN_ITER; i++) {
__asm__ __volatile__("NOP");
}
vTaskDelay(pdMS_TO_TICKS(100));
}
}
static void stats_task(void *arg)
{
xSemaphoreTake(sync_stats_task, portMAX_DELAY);
//Start all the spin tasks
for (int i = 0; i < NUM_OF_SPIN_TASKS; i++) {
xSemaphoreGive(sync_spin_task);
}
//Print real time stats periodically
while (1) {
printf("\n\nGetting real time stats over %d ticks\n", STATS_TICKS
); if (print_real_time_stats(STATS_TICKS) == ESP_OK) {
printf("Real time stats obtained\n"); } else {
printf("Error getting real time stats\n"); }
vTaskDelay(pdMS_TO_TICKS(1000));
}
}
void app_main(void)
{
//Allow other core to finish initialization
vTaskDelay(pdMS_TO_TICKS(100));
//Create semaphores to synchronize
sync_spin_task = xSemaphoreCreateCounting(NUM_OF_SPIN_TASKS, 0);
sync_stats_task = xSemaphoreCreateBinary();
//Create spin tasks
for (int i = 0; i < NUM_OF_SPIN_TASKS; i++) {
snprintf(task_names
[i
], configMAX_TASK_NAME_LEN
, "spin%d", i
); xTaskCreatePinnedToCore(spin_task, task_names[i], 1024, NULL, SPIN_TASK_PRIO, NULL, tskNO_AFFINITY);
}
//Create and start stats task
xTaskCreatePinnedToCore(stats_task, "stats", 4096, NULL, STATS_TASK_PRIO, NULL, tskNO_AFFINITY);
xSemaphoreGive(sync_stats_task);
}
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