Task voting watchdog for RTEMS

/**
 * @file task_watchdog.c
 *
 * @date Nov 27, 2022
 * @author peter
 * @brief
 *
 * @license
 *
 */


#include <stdint.h>
#include "app_result.h"

#define TASK_NUMBER_MAX 16

static struct {
        rtems_id id;
        uint32_t votes;
} registry[TASK_NUMBER_MAX]= {0};

static uint8_t registrants= 0;

// Call at the start of init task
void TaskWatchdog_Init(void) {
    hal_wdgInit();
}

// Call when task is created
AppResult_t TaskWatchdog_Register(rtems_id taskID, uint8_t * idx) {
    AppResult_t res= RESULT_ERR_WRONG_ARGUMENT;
    if (taskID != RTEMS_ID_NONE && idx) {
        res= RESULT_ERR_INSUFFICENT_RESOURCES;
        if (registrants < TASK_NUMBER_MAX) {
            registry[registrants].id= taskID;
            *idx= registrants;
            registrants+= 1;
            res= RESULT_OK;
        }
    }
    return res;
}

// Call in the loop in a task to be monitored
AppResult_t TaskWatchdog_Vote(uint8_t idx) {
    AppResult_t res= RESULT_ERR_WRONG_ARGUMENT;
    if (idx < TASK_NUMBER_MAX) {
        registry[idx].votes+= 1;
        res= RESULT_OK;
    }
    return res;
}

// Call in the background task
void TaskWatchdog_Handle(void) {
    uint8_t votes= 0;
    for (uint8_t i= 0; i < registrants; ++i) {
        if (registry[i].votes > 0) {
            votes+= 1;
        }
    }

    if (votes == registrants) {
        hal_wdgClear();
        for (uint8_t i= 0; i < registrants; ++i) {
            votes= 0;
        }
    }
}