/*
* schedule_tasks
*
* Description:
* Schedule tasks using EDF.
*
* Inputs:
* sched_task - an array of tasks to schedule
* n_tasks - number of tasks to schedule
*
* Outputs:
* none
*
* Returns:
* schedule_tasks return 0 upon success.
*
* Side Effects
* Job related fields in sched_task are modified.
*/
int schedule_tasks(task_t *sched_task, int n_tasks)
{
double now; /* current time */
double end; /* time to end simulation */
double energy; /* total energy used */
int index;
task_t *cur; /* pointer to current task */
tasks = sched_task;
ntask = n_tasks;
srandom(599);
/* all tasks are initially released at t = 0 */
for (index = 0 ; index < n_tasks ; index++) {
enqueue(&ready, &tasks[index]);
release(&tasks[index]);
}
wait = NULL;
freq = 1.0;
volts = 1.0;
energy = 0.0;
/* run simulation for 2x the hyperperiod */
end = compute_hyperperiod(tasks, n_tasks) * 2;
now = 0.0;
while(now < end) {
/* run next job in ready queue */
if (wait == NULL
|| (now + (ready->cur_exec - ready->usage)/freq
<= wait->next_evt)) {
/* job runs to completion (i.e., it's not preempted) */
energy += (ready->cur_exec - ready->usage)
* freq * volts * volts;
now = completion(now);
} else {
/* scheduling decision at next_evt */
run_job(ready, ready->job, now, wait->next_evt, freq);
ready->usage += (wait->next_evt - now) * freq;
energy += (wait->next_evt-now) * freq * volts * volts;
now = wait->next_evt;
}
if (ready == NULL) {
/* skip idle time until next release */
now = wait->next_evt;
}
/* release jobs in wait queue that are at release time */
while(wait && wait->next_evt <= now) {
cur = dequeue(&wait);
cur->next_evt += cur->deadline;
release(cur);
enqueue(&ready, cur);
}
}
printf("energy used = %f\n", energy);
return 0;
}
std::vector<int> compute_all_deadlines(Iter a, Iter b)
{
std::vector<int> dl;
int h = compute_hyperperiod(a, b, b-a);
for (Iter p = a; p!=b; ++p) {
int d = get_next_deadline(*p, 0);
while (d <= h) {
dl.push_back(d);
d = get_next_deadline(*p, d);
}
}
std::sort(dl.begin(), dl.end());
std::unique(dl.begin(), dl.end());
return dl;
}
