/*
this function creates a random realization of the session duration of a background-session
input:
output: - random realization of D_s (ms)
*/
int backgroundSessionDurationRnd(){
int duration;
duration = ceil(pow(10,exponential_dist(1/0.3591))*1000); /*ms*/
if(duration<0){
duration=0;
}else if(duration>1<<30){
duration=1<<30;
}
return duration;
}
/*
Simulate power law with cut-off x^(-alpha)*exp(-lambda*x)
To simulate power-law with cutoff , one can generate an
exponentially distributed random number using the formula
above (as k>0 and integer, so k start at 1)
and then accept or reject it with probability p or 1 - p
respectively (i.e accept U1 <p or reject U1>p, and
U1 is a uniform [0,1] random variable),
where p = (x/x_min)^(-alpha) and x_min=1.
http://www.santafe.edu/~aaronc/powerlaws/
*/
double rand_gen::powerlaw_dist(double alpha, double lamda)
{
double x;
do{
x = exponential_dist(lamda);
} while (pow(x,-1*alpha) < uniform_dist(0.,1.));
return (x);
}
void generate_taskset(char *path, int nr_tasksets,
char *dist, char *deadline, char *period, int workload,
double sep, double prob, double mean,
double umin, double umax, int pmin, int pmax)
{
int i, k;
char dir[MAX_BUF];
char file[MAX_BUF];
char cmd[MAX_BUF];
char str[MAX_BUF];
FILE *fp;
int nr_tasks;
double u, utotal, usys = (double)workload / 100.0;
taskdata_t *taskdata;
/* create taskset files, only if they do not exist. */
system("mkdir ./taskset >& .error.log");
/* create taskset/@dist. */
sprintf(path, "./taskset/%s", dist);
sprintf(cmd, "mkdir %s >& .error.log", path);;
system(cmd);
/* create taskset/@dist/@deadline. */
sprintf(path, "%s/%s", path, deadline);
sprintf(cmd, "mkdir %s >& .error.log", path);;
system(cmd);
/* create taskset/@dist/@deadline/@period. */
sprintf(path, "%s/%s", path, period);
sprintf(cmd, "mkdir %s >& .error.log", path);
system(cmd);
/* create taskset/@dist/@deadline/@parameters. */
if (strcmp(dist, "uniform") == 0) {
sprintf(path, "%s/pmin%d_pmax%d_umin%.2f_umax%.2f",
path, pmin, pmax, umin, umax);
sprintf(cmd, "mkdir %s >& .error.log", path);
}
else if (strcmp(dist, "bimodal") == 0) {
sprintf(path, "%s/pmin%d_pmax%d_umin%.2f_umax%.2f_sep%.2f_prob%.2f",
path, pmin, pmax, umin, umax, sep, prob);
sprintf(cmd, "mkdir %s >& .error.log", path);
}
else if (strcmp(deadline, "arbitrary") == 0) {
sprintf(path, "%s/pmin%d_pmax%d_mean%.2f", path,
pmin, pmax, mean);
sprintf(cmd, "mkdir %s >& .error.log", path);
}
else {
printf("Error: undefined deadline type!\n");
exit(1);
}
system(cmd);
/* create taskset/@dist/@deadline/@period/workload?. */
sprintf(dir, "%s/workload%d", path, workload);
sprintf(cmd, "mkdir %s >& .error.log", dir);
if (system(cmd) == 0) {
/* initialize random function seed. */
srand((unsigned int)time(NULL) + workload);
/* if --period=harmonic is chosen, make harmonic periods. */
if (strcmp(period, "harmonic") == 0) {
make_harmonic_periods(pmin, pmax);
}
/* generate tasksets for each workload. */
for (k = 1; k <= nr_tasksets; k++) {
/* determine utilizations based on a uniform distribution.
results will be written to a tempral file ".util". */
fp = fopen(".util", "w");
nr_tasks = 0;
utotal = 0.0;
while (1) {
nr_tasks++;
if (strcmp(dist, "uniform") == 0) {
u = uniform_dist(umin, umax);
}
else if (strcmp(dist, "bimodal") == 0) {
u = bimodal_dist(umin, umax, sep, prob);
}
else if (strcmp(dist, "exponential") == 0) {
u = exponential_dist(mean);
}
else {
printf("Error: undefined distribution!\n");
exit(1);
}
utotal += u;
if (utotal <= usys) {
fprintf(fp, "%f\n", u);
}
else {
u -= (utotal - usys);
fprintf(fp, "%f\n", u);
break;
}
}
fclose(fp);
/* task data will be stored here. */
taskdata = (taskdata_t*) malloc(sizeof(taskdata_t) * nr_tasks);
/* reopen the temporal file to determine C, T, and D. */
fp = fopen(".util", "r");
/* determine computation times and periods. */
for (i = 0; i < nr_tasks; i++) {
fgets(str, MAX_BUF, fp);
taskdata[i].U = atof(str);
if (strcmp(period, "harmonic") == 0) {
taskdata[i].T = harmonic_periods[rand()%nr_periods];
}
else {
taskdata[i].T = pmin + rand()%(pmax-pmin);
}
taskdata[i].C = taskdata[i].U * taskdata[i].T;
}
/* determine relative deadlines. */
if (strcmp(deadline, "implicit") == 0) {
for (i = 0; i < nr_tasks; i++) {
taskdata[i].D = taskdata[i].T;
}
}
else if (strcmp(deadline, "constrained") == 0) {
for (i = 0; i < nr_tasks; i++) {
taskdata[i].D = taskdata[i].C +
rand()%(taskdata[i].T - taskdata[i].C);
}
}
else if (strcmp(deadline, "arbitrary") == 0) {
for (i = 0; i < nr_tasks; i++) {
taskdata[i].D = taskdata[i].C +
rand()%(4*taskdata[i].T - taskdata[i].C);
}
}
else {
printf("Error: undefined deadline type!\n");
exit(1);
}
fclose(fp);
/* generate a taskset file. */
sprintf(file, "%s/ts%d", dir, k);
if ((fp = fopen(file, "w")) == NULL) {
printf("Cannot open %s\n", file);
return;
}
fprintf(fp, "# the number of tasks\n");
fprintf(fp, "%d\n", nr_tasks);
fprintf(fp, "# tasks (name, C, T, D)\n");
for (i = 0; i < nr_tasks; i++) {
fprintf(fp, "task%d, %d, %d, %d\n",
i, taskdata[i].C, taskdata[i].T, taskdata[i].D);
}
fclose(fp);
free(taskdata);
}
/* if --period=harmonic is chosen, free harmonic periods. */
if (strcmp(period, "harmonic") == 0) {
free(harmonic_periods);
}
}
}
