From 4c3e55e7621418176aeed0bfd01555b79e1bae35 Mon Sep 17 00:00:00 2001
From: Felipe Cerqueira <felipec@mpi-sws.org>
Date: Fri, 21 Oct 2016 15:37:02 +0200
Subject: [PATCH] Remove repeated lemmas
---
model/arrival_bounds.v | 99 ++++--------------------------------------
1 file changed, 8 insertions(+), 91 deletions(-)
diff --git a/model/arrival_bounds.v b/model/arrival_bounds.v
index a7bdebc83..a0b90b993 100644
--- a/model/arrival_bounds.v
+++ b/model/arrival_bounds.v
@@ -24,7 +24,7 @@ Module ArrivalBounds.
(* In this section, we prove an upper bound on the number of jobs that can arrive
in any interval. *)
- Section SporadicArrivalsAfterQuietTime.
+ Section BoundOnSporadicArrivals.
(* Assume that jobs are sporadic. *)
Hypothesis H_sporadic_tasks: sporadic_task_model task_period arr_seq job_task.
@@ -119,106 +119,23 @@ Module ArrivalBounds.
Let a_first := job_arrival j_first.
Let a_last := job_arrival j_last.
- (* Next, we prove some auxiliary lemmas.
- First, we show that the jobs in the sequence satisfy some basic properties... *)
- Local Corollary sporadic_arrival_bound_properties_of_nth:
+ (* Recall from task_arrival.v the properties of the n-th job ...*)
+ Corollary sporadic_arrival_bound_properties_of_nth:
forall idx,
idx < num_arrivals ->
t1 <= job_arrival (nth_task idx) < t2 /\
job_task (nth_task idx) = tsk.
Proof.
intros idx LTidx.
- have IN: nth_task idx \in sorted_jobs by rewrite mem_nth // size_sort.
- rewrite mem_sort in IN.
- rewrite 2!mem_filter in IN.
- move: IN => /andP [JOB /andP [GE LT]]; apply JobIn_arrived in LT.
- split; last by apply/eqP.
- by apply/andP; split.
+ by apply sorted_arrivals_properties_of_nth.
Qed.
- (* ...and that consecutive jobs in the sequence are different. *)
- Local Corollary sporadic_arrival_bound_current_differs_from_next:
- forall idx,
- idx < num_arrivals.-1 ->
- nth_task idx <> nth_task idx.+1.
- Proof.
- rename H_at_least_two_jobs into TWO.
- intros idx LT; apply/eqP.
- rewrite nth_uniq ?size_sort /arriving_jobs -/(num_arrivals_of_task _ _ _ _ _)
- -/num_arrivals; first by rewrite neq_ltn ltnSn orTb.
- {
- apply leq_trans with (n := num_arrivals.-1); first by done.
- by destruct num_arrivals; first by rewrite ltn0 in TWO.
- }
- {
- destruct num_arrivals; first by rewrite ltn0 in TWO.
- by simpl in LT; rewrite ltnS.
- }
- {
- rewrite sort_uniq filter_uniq // filter_uniq //.
- by apply JobIn_uniq.
- }
- Qed.
-
- (* Since the list is sorted, we prove that each job arrives at
- least (task_period tsk) time units after the previous job. *)
- Lemma sporadic_arrival_bound_separated_by_period:
- forall idx,
- idx < num_arrivals.-1 ->
- job_arrival (nth_task idx.+1) >= job_arrival (nth_task idx) + task_period tsk.
- Proof.
- have NTH := sporadic_arrival_bound_properties_of_nth.
- have NEQ := sporadic_arrival_bound_current_differs_from_next.
- rename H_sporadic_tasks into SPO, H_at_least_two_jobs into TWO.
- intros idx LT.
- exploit (NTH idx); last intro NTH1.
- {
- apply leq_trans with (n := num_arrivals.-1); first by done.
- by destruct num_arrivals; first by rewrite ltn0 in TWO.
- }
- exploit (NTH idx.+1); last intro NTH2.
- {
- destruct num_arrivals; first by rewrite ltn0 in TWO.
- by simpl in LT; rewrite ltnS.
- }
- move: NTH1 NTH2 => [_ JOB1] [_ JOB2].
- rewrite -JOB1.
- apply SPO; [by apply NEQ | by rewrite JOB1 JOB2 |].
- suff ORDERED: by_arrival_time (nth_task idx) (nth_task idx.+1) by done.
- apply sort_ordered;
- first by apply sort_sorted; intros x y; apply leq_total.
- by rewrite size_sort.
- Qed.
-
- (* By induction, we prove that that each job with index 'idx' arrives at
- least idx*(task_period tsk) units after the first job. *)
- Lemma sporadic_arrival_bound_distance_from_first_job:
- forall idx,
- idx < num_arrivals ->
- job_arrival (nth_task idx) >= a_first + idx * task_period tsk.
- Proof.
- have SEP := sporadic_arrival_bound_separated_by_period.
- unfold sporadic_task_model in *.
- rename H_sporadic_tasks into SPO.
- induction idx; first by intros _; rewrite mul0n addn0.
- intros LT.
- have LT': idx < num_arrivals by apply leq_ltn_trans with (n := idx.+1).
- specialize (IHidx LT').
- apply leq_trans with (n := job_arrival (nth_task idx) + task_period tsk);
- first by rewrite mulSn [task_period _ + _]addnC addnA leq_add2r.
- apply SEP.
- by rewrite -(ltn_add2r 1) 2!addn1 (ltn_predK LT).
- Qed.
-
- (* Therefore, the first and last jobs are separated by at least
- (num_arrivals - 1) periods. *)
+ (* ...and the distance between the first and last jobs. *)
Corollary sporadic_arrival_bound_distance_between_first_and_last:
a_last >= a_first + (num_arrivals-1) * task_period tsk.
Proof.
- have DIST := sporadic_arrival_bound_distance_from_first_job.
- rename H_at_least_two_jobs into TWO.
- rewrite subn1; apply DIST.
- by destruct num_arrivals; first by rewrite ltn0 in TWO.
+ apply sorted_arrivals_distance_between_first_and_last; try (by done).
+ by apply leq_ltn_trans with (n := 1).
Qed.
(* Because the number of arrivals is larger than the ceiling term,
@@ -300,7 +217,7 @@ Module ArrivalBounds.
by apply sporadic_task_arrival_bound_at_least_two_jobs; rewrite CEIL.
Qed.
- End SporadicArrivalsAfterQuietTime.
+ End BoundOnSporadicArrivals.
End Lemmas.
--
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