Support budget enforcement policies. Allows tasks to specify

how their execution budgets should be enforced: NO_ENFORCEMENT,
QUANTUM_ENFORCEMENT, and PRECISE_ENFORCEMENT (unsupported).

NOTE: Users of NO_ENFORCEMENT must call sleep_next_period() at the
end of every job to signal to the kernel that its job is complete.

2 files changed, 10 insertions, 3 deletions

diff --git a/src/litmus.c b/src/litmus.c
index 5f98b97..f71f337 100644
--- a/src/litmus.c
+++ b/src/litmus.c
@@ -42,14 +42,16 @@ int be_migrate_to(int target_cpu)
 }
 
 int sporadic_task(lt_t e, lt_t p, lt_t phase,
-                  int cpu, task_class_t cls, int set_cpu_set)
+                  int cpu, task_class_t cls,
+                  budget_policy_t budget_policy, int set_cpu_set)
 {
         return sporadic_task_ns(e * NS_PER_MS, p * NS_PER_MS, phase * NS_PER_MS,
-                                cpu, cls, set_cpu_set);
+                                cpu, cls, budget_policy, set_cpu_set);
 }
 
 int sporadic_task_ns(lt_t e, lt_t p, lt_t phase,
-                     int cpu, task_class_t cls, int set_cpu_set)
+                        int cpu, task_class_t cls,
+                        budget_policy_t budget_policy, int set_cpu_set)
 {
         struct rt_task param;
         int ret;
@@ -58,6 +60,8 @@ int sporadic_task_ns(lt_t e, lt_t p, lt_t phase,
         param.cpu       = cpu;
         param.cls       = cls;
         param.phase     = phase;
+        param.budget_policy = budget_policy;
+
         if (set_cpu_set) {             
                 ret = be_migrate_to(cpu);
                 check("migrate to cpu");
diff --git a/src/task.c b/src/task.c
index f9e4ccf..4d237bd 100644
--- a/src/task.c
+++ b/src/task.c
@@ -49,6 +49,9 @@ int __create_rt_task(rt_fn_t rt_prog, void *arg, int cpu, int wcet, int period,
         params.exec_cost = wcet;
         params.cls       = class;
         params.phase     = 0;
+        /* enforce budget for tasks that might not use sleep_next_period() */
+        params.budget_policy = QUANTUM_ENFORCEMENT;
+
         return __launch_rt_task(rt_prog, arg,
                                 (rt_setup_fn_t) set_rt_task_param, &params);
 }