FreeRTOS Semaphore API

main_semaphore.c

/**
 * Adapted from: https://microcontrollerslab.com/freertos-binary-semaphore-tasks-interrupt-synchronization-u-arduino/
*/

#include <stdio.h>
#include <pthread.h>

#include "FreeRTOS.h"
#include "semphr.h"

SemaphoreHandle_t semaphore;

void semaphore_task1(void *_)
{
    while (1)
    {

        xSemaphoreTake(semaphore, portMAX_DELAY);
        printf("[1] Take... \r\n");
        xSemaphoreGive(semaphore);
        vTaskDelay(1);
    }
}

void semaphore_task2(void *_)
{
    while (1)
    {
        xSemaphoreTake(semaphore, portMAX_DELAY);
        printf("[2] Take... \r\n");
        xSemaphoreGive(semaphore);
        vTaskDelay(1);
    }
}

void main_semaphore()
{
    semaphore = xSemaphoreCreateBinary();
    xSemaphoreGive(semaphore);

    if (!semaphore)
    {
        printf("Failed to obtain sempahore.\r\n");
    }

    xTaskCreate(semaphore_task1, "Take", configMINIMAL_STACK_SIZE, NULL, 1, NULL);
    xTaskCreate(semaphore_task2, "Give", configMINIMAL_STACK_SIZE, NULL, 1, NULL);
    vTaskStartScheduler();

    for (;;)
        ;
}