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#include "tasks.h"
#include "schedulability.h"
#include "edf/load.h"
#include <iostream>
#include <algorithm>
/* This implements the LOAD test presented in:
*
* Baker & Baruah (2009), An analysis of global EDF schedulability for
* arbitrary-deadline sporadic task systems, Real-Time Systems, volume 43,
* pages 3-24.
*/
bool LoadGedf::is_schedulable(const TaskSet &ts, bool check_preconditions)
{
if (check_preconditions)
{
if (!(ts.has_only_feasible_tasks()
&& ts.is_not_overutilized(m)))
return false;
}
fractional_t load, max_density, mu, bound, cond1, cond2;
integral_t mu_ceil;
// get the load of the task set
ts.approx_load(load, epsilon);
// compute bound (corollary 2)
ts.get_max_density(max_density);
mu = m - (m - 1) * max_density;
mu_ceil = mu.get_num();
// divide with ceiling
mpz_cdiv_q(mu_ceil.get_mpz_t(),
mu.get_num().get_mpz_t(),
mu.get_den().get_mpz_t());
cond1 = mu - (mu_ceil - 1) * max_density;
cond2 = (mu_ceil - 1) - (mu_ceil - 2) * max_density;
bound = std::max(cond1, cond2);
return load <= bound;
}
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