shitty threading clone

taskmgr.c

#include "taskmgr.h"

void taskmgr_UpdateCurrentTime(int Time)
{
    //set taskmgr current time
    taskmgr_Time = Time;
}

int taskmgr_RegisterTask(int ExecuteAt, void* Function)
{
    //init tasks count
    if (taskmgr_TasksCount == -1)
    {
        taskmgr_TasksCount++;
    }

    //setup task
    taskmgr_Tasks[taskmgr_TasksCount].taskmgr_ExecuteAt = ExecuteAt;
    taskmgr_Tasks[taskmgr_TasksCount].taskmgr_Function = &Function;

    //increcement tasks count
    taskmgr_TasksCount++;

    //return task id
    return taskmgr_TasksCount - 1;
}

void taskmgr_ExecuteAll()
{
    //no tasks to execute
    if (taskmgr_TasksCount < 0)
    {
        return TASKMGR_NO_TASKS;
    }

    //loop through struct array
    for (int Index = 0; Index < taskmgr_TasksCount; Index++)
    {
        //check if execution time for task equals taskmgr current time
        if (taskmgr_Tasks[Index].ExecuteAt == taskmgr_Time)
        {
            //execute void function
            ((void(*)()) taskmgr_Tasks[Index].taskmgr_Function)();
        }
    }
}

int taskmgr_Execute(int Index)
{
    //no tasks to execute
    if (taskmgr_TasksCount < 0)
    {
        return TASKMGR_NO_TASKS;
    }

    //index is invalid, either higher than tasks count or lower than tasks count
    if (Index > taskmgr_TasksCount)
    {
        return TASKMGR_INVALID_INDEX;
    }
    else if (Index < taskmgr_TasksCount)
    {
        return TASKMGR_INVALID_INDEX;
    }

    //execute void function
    ((void(*)()) taskmgr_Tasks[Index].taskmgr_Function)();
}

taskmgr.h

//err codes
#define TASKMGR_NO_TASKS 0
#define TASKMGR_INVALID_INDEX 1

struct taskmgr_Task
{
    int taskmgr_ExecuteAt;
    void* taskmgr_Function;
};

int taskmgr_Time;
int taskmgr_TasksCount = -1;
struct taskmgr_Task taskmgr_Tasks[];

void taskmgr_UpdateCurrentTime(int Time);
int taskmgr_RegisterTask(int ExecuteAt, void* Function);
void taskmgr_ExecuteAll();
int taskmgr_Execute(int Index);