main.c

#include "main.h"


/*global vars*/

cst_config *config;


int main(int argc, char* argv[]){
    extern int errno;
    int i = 0, command = 0;
    unsigned long cookie;

    checkRoot();

    if((config = loadConfiguration(argc, argv))==NULL){
        printHelp();
        exit(EXIT_FAILURE);
    }

    

    //ckeck that no error returns from prctl() to ensure that CORE SCHEDULING returns no errors
    if(prctl(PR_SCHED_CORE, PR_SCHED_CORE_GET, getpid(), 0, &cookie) == -1)
        handlePrctlError();

    /*
        Since an api that allows to directly push a cookie to a certain task i not available,
        Firstly tis program must be added to the target core scheduling group, and
        then add the <list of task id> tasks to the group
    */
        
    switch (config->cmd)
    {
    case CREATE_GROUP:
        prctl(PR_SCHED_CORE, PR_SCHED_CORE_CREATE, getpid(), config->coreScope, NULL);
        pushCookie();
        break;

    case ADD_TASK_TO_GROUP:
        prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_FROM, config->shareFromTask , config->coreScope, NULL);
        pushCookie();
        break;

    case CLEAR_TASK:
        pushCookie();
        break;

    case PEEK_TASK:
        printf("Task\tCookie\n");
        for(i=0;i<config->numberOfTask;i++){
            prctl(PR_SCHED_CORE, PR_SCHED_CORE_GET, config->listOfTask[i] , config->coreScope, &cookie);
            printf("[%d]\t[%lu]\n", config->listOfTask[i], cookie);
        }
        printf("\n");
        break;

    case EXEC_TASK: 
        //if a cookie has already been set for another task, i will not set another cookie
        //and i will be using the one already created so that the new task will run in core scheduling
        //with the others
        prctl(PR_SCHED_CORE, PR_SCHED_CORE_GET, getpid() , config->coreScope, &cookie);

        if(cookie == 0) //if cookie is not set, i set a new cookie
            prctl(PR_SCHED_CORE, PR_SCHED_CORE_CREATE, getpid(), config->coreScope, NULL);

        if(config->verbose){
            prctl(PR_SCHED_CORE, PR_SCHED_CORE_GET, getpid() , config->coreScope, &cookie);
            printf("Setting core scheduling and executing program: %s\n", argv[config->execPosition]);
            printf("Task id \tCookie\n[%d] \t[%lu]\n\n", getpid(), cookie);
        }  

        //execute the new exec_task
        execvp(argv[config->execPosition], argv+config->execPosition );
        printf("Error: unable to start program!\nError is: %s\n", strerror(errno));
        exit(EXIT_FAILURE);
        break;
    
    default:
        printf("Error: unknown prctl command\n");
        printConfiguration(config);
        exit(EXIT_FAILURE);
        break;
    }



    if(config->verbose){
        printConfiguration(config);
        printCookies(config);
    }
    
    
    exit(EXIT_SUCCESS);
}