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From iris.algebra Require Import auth gmap.
From iris.base_logic Require Export gen_heap.
From iris.base_logic.lib Require Export proph_map.
From iris.program_logic Require Export weakestpre.
From iris.program_logic Require Import ectx_lifting total_ectx_lifting.
From iris.heap_lang Require Export lang.
From iris.heap_lang Require Import tactics notation.
From iris.proofmode Require Import tactics.
From stdpp Require Import fin_maps.
Set Default Proof Using "Type".
Class heapG Σ := HeapG {
heapG_invG : invG Σ;
heapG_gen_heapG :> gen_heapG loc val Σ;
heapG_proph_mapG :> proph_mapG proph_id (val * val) Σ
}.
Instance heapG_irisG `{!heapG Σ} : irisG heap_lang Σ := {
iris_invG := heapG_invG;
state_interp σ κs _ :=
(gen_heap_ctx σ.(heap) ∗ proph_map_ctx κs σ.(used_proph_id))%I;
fork_post _ := True%I;
}.
(** Override the notations so that scopes and coercions work out *)
Notation "l ↦{ q } v" := (mapsto (L:=loc) (V:=val) l q v%V)
(at level 20, q at level 50, format "l ↦{ q } v") : bi_scope.
Notation "l ↦ v" :=
(mapsto (L:=loc) (V:=val) l 1 v%V) (at level 20) : bi_scope.
Notation "l ↦{ q } -" := (∃ v, l ↦{q} v)%I
(at level 20, q at level 50, format "l ↦{ q } -") : bi_scope.
Notation "l ↦ -" := (l ↦{1} -)%I (at level 20) : bi_scope.
Definition array `{!heapG Σ} (l : loc) (vs : list val) : iProp Σ :=
([∗ list] i ↦ v ∈ vs, (l +ₗ i) ↦ v)%I.
Notation "l ↦∗ vs" := (array l vs)
(at level 20, format "l ↦∗ vs") : bi_scope.
(** The tactic [inv_head_step] performs inversion on hypotheses of the shape
[head_step]. The tactic will discharge head-reductions starting from values, and
simplifies hypothesis related to conversions from and to values, and finite map
operations. This tactic is slightly ad-hoc and tuned for proving our lifting
lemmas. *)
Ltac inv_head_step :=
repeat match goal with
| _ => progress simplify_map_eq/= (* simplify memory stuff *)
| H : to_val _ = Some _ |- _ => apply of_to_val in H
| H : head_step ?e _ _ _ _ _ |- _ =>
try (is_var e; fail 1); (* inversion yields many goals if [e] is a variable
and can thus better be avoided. *)
inversion H; subst; clear H
end.
Local Hint Extern 0 (head_reducible _ _) => eexists _, _, _, _; simpl : core.
Local Hint Extern 0 (head_reducible_no_obs _ _) => eexists _, _, _; simpl : core.
(* [simpl apply] is too stupid, so we need extern hints here. *)
Local Hint Extern 1 (head_step _ _ _ _ _ _) => econstructor : core.
Local Hint Extern 0 (head_step (CAS _ _ _) _ _ _ _ _) => eapply CasS : core.
Local Hint Extern 0 (head_step (AllocN _ _) _ _ _ _ _) => apply alloc_fresh : core.
Local Hint Extern 0 (head_step NewProph _ _ _ _ _) => apply new_proph_id_fresh : core.
Local Hint Resolve to_of_val : core.
Instance into_val_val v : IntoVal (Val v) v.
Proof. done. Qed.
Instance as_val_val v : AsVal (Val v).
Proof. by eexists. Qed.
Local Ltac solve_atomic :=
apply strongly_atomic_atomic, ectx_language_atomic; [inversion 1; naive_solver
|apply ectxi_language_sub_redexes_are_values; intros [] **; naive_solver].
Instance alloc_atomic s v w : Atomic s (AllocN (Val v) (Val w)).
Proof. solve_atomic. Qed.
Instance load_atomic s v : Atomic s (Load (Val v)).
Proof. solve_atomic. Qed.
Instance store_atomic s v1 v2 : Atomic s (Store (Val v1) (Val v2)).
Proof. solve_atomic. Qed.
Instance cas_atomic s v0 v1 v2 : Atomic s (CAS (Val v0) (Val v1) (Val v2)).
Proof. solve_atomic. Qed.
Instance faa_atomic s v1 v2 : Atomic s (FAA (Val v1) (Val v2)).
Proof. solve_atomic. Qed.
Instance fork_atomic s e : Atomic s (Fork e).
Proof. solve_atomic. Qed.
Instance skip_atomic s : Atomic s Skip.
Proof. solve_atomic. Qed.
Instance new_proph_atomic s : Atomic s NewProph.
Proof. solve_atomic. Qed.
Instance binop_atomic s op v1 v2 : Atomic s (BinOp op (Val v1) (Val v2)).
Proof. solve_atomic. Qed.
Instance proph_resolve_atomic s e v1 v2 :
Atomic s e → Atomic s (Resolve e (Val v1) (Val v2)).
Proof.
rename e into e1. intros H σ1 e2 κ σ2 efs [Ks e1' e2' Hfill -> step].
simpl in *. induction Ks as [|K Ks _] using rev_ind; simpl in Hfill.
- subst. inversion_clear step. by apply (H σ1 (Val v) κs σ2 efs), head_prim_step.
- rewrite fill_app. rewrite fill_app in Hfill.
assert (∀ v, Val v = fill Ks e1' → False) as fill_absurd.
{ intros v Hv. assert (to_val (fill Ks e1') = Some v) as Htv by by rewrite -Hv.
apply to_val_fill_some in Htv. destruct Htv as [-> ->]. inversion step. }
destruct K; (inversion Hfill; clear Hfill; subst; try
match goal with | H : Val ?v = fill Ks e1' |- _ => by apply fill_absurd in H end).
refine (_ (H σ1 (fill (Ks ++ [K]) e2') _ σ2 efs _)).
+ destruct s; intro Hs; simpl in *.
* destruct Hs as [v Hs]. apply to_val_fill_some in Hs. by destruct Hs, Ks.
* apply irreducible_resolve. by rewrite fill_app in Hs.
+ econstructor 1 with (K := Ks ++ [K]); try done. simpl. by rewrite fill_app.
Qed.
Instance resolve_proph_atomic s v1 v2 : Atomic s (ResolveProph (Val v1) (Val v2)).
Proof. by apply proph_resolve_atomic, skip_atomic. Qed.
Local Ltac solve_exec_safe := intros; subst; do 3 eexists; econstructor; eauto.
Local Ltac solve_exec_puredet := simpl; intros; by inv_head_step.
Local Ltac solve_pure_exec :=
subst; intros ?; apply nsteps_once, pure_head_step_pure_step;
constructor; [solve_exec_safe | solve_exec_puredet].
(** The behavior of the various [wp_] tactics with regard to lambda differs in
the following way:
- [wp_pures] does *not* reduce lambdas/recs that are hidden behind a definition.
- [wp_rec] and [wp_lam] reduce lambdas/recs that are hidden behind a definition.
To realize this behavior, we define the class [AsRecV v f x erec], which takes a
value [v] as its input, and turns it into a [RecV f x erec] via the instance
[AsRecV_recv : AsRecV (RecV f x e) f x e]. We register this instance via
[Hint Extern] so that it is only used if [v] is syntactically a lambda/rec, and
not if [v] contains a lambda/rec that is hidden behind a definition.
To make sure that [wp_rec] and [wp_lam] do reduce lambdas/recs that are hidden
behind a definition, we activate [AsRecV_recv] by hand in these tactics. *)
Class AsRecV (v : val) (f x : binder) (erec : expr) :=
as_recv : v = RecV f x erec.
Hint Mode AsRecV ! - - - : typeclass_instances.
Definition AsRecV_recv f x e : AsRecV (RecV f x e) f x e := eq_refl.
Hint Extern 0 (AsRecV (RecV _ _ _) _ _ _) =>
apply AsRecV_recv : typeclass_instances.
Instance pure_recc f x (erec : expr) :
PureExec True 1 (Rec f x erec) (Val $ RecV f x erec).
Proof. solve_pure_exec. Qed.
Instance pure_pairc (v1 v2 : val) :
PureExec True 1 (Pair (Val v1) (Val v2)) (Val $ PairV v1 v2).
Proof. solve_pure_exec. Qed.
Instance pure_injlc (v : val) :
PureExec True 1 (InjL $ Val v) (Val $ InjLV v).
Proof. solve_pure_exec. Qed.
Instance pure_injrc (v : val) :
PureExec True 1 (InjR $ Val v) (Val $ InjRV v).
Proof. solve_pure_exec. Qed.
Instance pure_beta f x (erec : expr) (v1 v2 : val) `{!AsRecV v1 f x erec} :
PureExec True 1 (App (Val v1) (Val v2)) (subst' x v2 (subst' f v1 erec)).
Proof. unfold AsRecV in *. solve_pure_exec. Qed.
Instance pure_unop op v v' :
PureExec (un_op_eval op v = Some v') 1 (UnOp op (Val v)) (Val v').
Proof. solve_pure_exec. Qed.
Instance pure_binop op v1 v2 v' :
PureExec (bin_op_eval op v1 v2 = Some v') 1 (BinOp op (Val v1) (Val v2)) (Val v').
Proof. solve_pure_exec. Qed.
Instance pure_if_true e1 e2 : PureExec True 1 (If (Val $ LitV $ LitBool true) e1 e2) e1.
Proof. solve_pure_exec. Qed.
Instance pure_if_false e1 e2 : PureExec True 1 (If (Val $ LitV $ LitBool false) e1 e2) e2.
Proof. solve_pure_exec. Qed.
Instance pure_fst v1 v2 :
PureExec True 1 (Fst (Val $ PairV v1 v2)) (Val v1).
Proof. solve_pure_exec. Qed.
Instance pure_snd v1 v2 :
PureExec True 1 (Snd (Val $ PairV v1 v2)) (Val v2).
Proof. solve_pure_exec. Qed.
Instance pure_case_inl v e1 e2 :
PureExec True 1 (Case (Val $ InjLV v) e1 e2) (App e1 (Val v)).
Proof. solve_pure_exec. Qed.
Instance pure_case_inr v e1 e2 :
PureExec True 1 (Case (Val $ InjRV v) e1 e2) (App e2 (Val v)).
Proof. solve_pure_exec. Qed.
Section lifting.
Context `{!heapG Σ}.
Implicit Types P Q : iProp Σ.
Implicit Types Φ : val → iProp Σ.
Implicit Types efs : list expr.
Implicit Types σ : state.
Implicit Types v : val.
Implicit Types vs : list val.
Implicit Types l : loc.
Implicit Types sz off : nat.
(** Fork: Not using Texan triples to avoid some unnecessary [True] *)
Lemma wp_fork s E e Φ :
▷ WP e @ s; ⊤ {{ _, True }} -∗ ▷ Φ (LitV LitUnit) -∗ WP Fork e @ s; E {{ Φ }}.
Proof.
iIntros "He HΦ". iApply wp_lift_atomic_head_step; [done|].
iIntros (σ1 κ κs n) "Hσ !>"; iSplit; first by eauto.
iNext; iIntros (v2 σ2 efs Hstep); inv_head_step. by iFrame.
Qed.
Lemma twp_fork s E e Φ :
WP e @ s; ⊤ [{ _, True }] -∗ Φ (LitV LitUnit) -∗ WP Fork e @ s; E [{ Φ }].Proof.
iIntros "He HΦ". iApply twp_lift_atomic_head_step; [done|].
iIntros (σ1 κs n) "Hσ !>"; iSplit; first by eauto.
iIntros (κ v2 σ2 efs Hstep); inv_head_step. by iFrame.
Qed.
Lemma array_nil l : l ↦∗ [] ⊣⊢ emp.
Proof. by rewrite /array. Qed.
Lemma array_singleton l v : l ↦∗ [v] ⊣⊢ l ↦ v.
Proof. by rewrite /array /= right_id loc_add_0. Qed.
Lemma array_app l vs ws :
l ↦∗ (vs ++ ws) ⊣⊢ l ↦∗ vs ∗ (l +ₗ length vs) ↦∗ ws.
Proof.
rewrite /array big_sepL_app.
setoid_rewrite Nat2Z.inj_add.
by setoid_rewrite loc_add_assoc.
Qed.
Lemma array_cons l v vs : l ↦∗ (v :: vs) ⊣⊢ l ↦ v ∗ (l +ₗ 1) ↦∗ vs.
Proof.
rewrite /array big_sepL_cons loc_add_0.
setoid_rewrite loc_add_assoc.
setoid_rewrite Nat2Z.inj_succ.
by setoid_rewrite Z.add_1_l.
Qed.
Lemma heap_array_to_array l vs :
([∗ map] l' ↦ v ∈ heap_array l vs, l' ↦ v) -∗ l ↦∗ vs.
Proof.
iIntros "Hvs". iInduction vs as [|v vs] "IH" forall (l); simpl.
{ by rewrite /array. }
rewrite big_opM_union; last first.
{ apply map_disjoint_spec=> l' v1 v2 /lookup_singleton_Some [-> _].
intros (j&?&Hjl&_)%heap_array_lookup.
rewrite loc_add_assoc -{1}[l']loc_add_0 in Hjl. simplify_eq; lia. }
rewrite array_cons.
rewrite big_opM_singleton; iDestruct "Hvs" as "[$ Hvs]".
by iApply "IH".
Qed.
Lemma heap_array_to_seq_meta l vs n :
length vs = n →
([∗ map] l' ↦ _ ∈ heap_array l vs, meta_token l' ⊤) -∗
[∗ list] i ∈ seq 0 n, meta_token (l +ₗ (i : nat)) ⊤.
Proof.
iIntros (<-) "Hvs". iInduction vs as [|v vs] "IH" forall (l)=> //=.
rewrite big_opM_union; last first.
{ apply map_disjoint_spec=> l' v1 v2 /lookup_singleton_Some [-> _].
intros (j&?&Hjl&_)%heap_array_lookup.
rewrite loc_add_assoc -{1}[l']loc_add_0 in Hjl. simplify_eq; lia. }
rewrite loc_add_0 -fmap_seq big_sepL_fmap.
setoid_rewrite Nat2Z.inj_succ. setoid_rewrite <-Z.add_1_l.
setoid_rewrite <-loc_add_assoc.
rewrite big_opM_singleton; iDestruct "Hvs" as "[$ Hvs]". by iApply "IH".
Qed.
Lemma update_array l vs off v :
vs !! off = Some v →
(l ↦∗ vs -∗ ((l +ₗ off) ↦ v ∗ ∀ v', (l +ₗ off) ↦ v' -∗ l ↦∗ <[off:=v']>vs))%I.
Proof.
iIntros (Hlookup) "Hl".
rewrite -[X in (l ↦∗ X)%I](take_drop_middle _ off v); last done.
iDestruct (array_app with "Hl") as "[Hl1 Hl]".
iDestruct (array_cons with "Hl") as "[Hl2 Hl3]".
assert (off < length vs)%nat as H by (apply lookup_lt_is_Some; by eexists).
rewrite take_length min_l; last by lia. iFrame "Hl2".
iIntros (w) "Hl2".
clear Hlookup. assert (<[off:=w]> vs !! off = Some w) as Hlookup. { apply list_lookup_insert. lia. }
rewrite -[in (l ↦∗ <[off:=w]> vs)%I](take_drop_middle (<[off:=w]> vs) off w Hlookup).
iApply array_app. rewrite take_insert; last by lia. iFrame.
iApply array_cons. rewrite take_length min_l; last by lia. iFrame.
rewrite drop_insert; last by lia. done.
Qed.
(** Heap *)
Lemma wp_allocN s E v n :
0 < n →
{{{ True }}} AllocN (Val $ LitV $ LitInt $ n) (Val v) @ s; E
{{{ l, RET LitV (LitLoc l); l ↦∗ replicate (Z.to_nat n) v ∗
[∗ list] i ∈ seq 0 (Z.to_nat n), meta_token (l +ₗ (i : nat)) ⊤ }}}.
Proof.
iIntros (Hn Φ) "_ HΦ". iApply wp_lift_atomic_head_step_no_fork; auto.
iIntros (σ1 κ κs k) "[Hσ Hκs] !>"; iSplit; first by auto with lia.
iNext; iIntros (v2 σ2 efs Hstep); inv_head_step.
iMod (@gen_heap_alloc_gen with "Hσ") as "(Hσ & Hl & Hm)".
{ apply (heap_array_map_disjoint _ l (replicate (Z.to_nat n) v)); eauto.
rewrite replicate_length Z2Nat.id; auto with lia. }
iModIntro; iSplit; first done. iFrame "Hσ Hκs". iApply "HΦ". iSplitL "Hl".
- by iApply heap_array_to_array.
- iApply (heap_array_to_seq_meta with "Hm"). by rewrite replicate_length.
Qed.
Lemma twp_allocN s E v n :
0 < n →
[[{ True }]] AllocN (Val $ LitV $ LitInt $ n) (Val v) @ s; E
[[{ l, RET LitV (LitLoc l); l ↦∗ replicate (Z.to_nat n) v ∗
[∗ list] i ∈ seq 0 (Z.to_nat n), meta_token (l +ₗ (i : nat)) ⊤ }]].
Proof.
iIntros (Hn Φ) "_ HΦ". iApply twp_lift_atomic_head_step_no_fork; auto.
iIntros (σ1 κs k) "[Hσ Hκs] !>"; iSplit; first by destruct n; auto with lia.
iIntros (κ v2 σ2 efs Hstep); inv_head_step.
iMod (@gen_heap_alloc_gen with "Hσ") as "(Hσ & Hl & Hm)".
{ apply (heap_array_map_disjoint _ l (replicate (Z.to_nat n) v)); eauto.
rewrite replicate_length Z2Nat.id; auto with lia. }
iModIntro; do 2 (iSplit; first done). iFrame "Hσ Hκs". iApply "HΦ". iSplitL "Hl".
- by iApply heap_array_to_array.
- iApply (heap_array_to_seq_meta with "Hm"). by rewrite replicate_length.
Qed.
Lemma wp_alloc s E v :
{{{ True }}} Alloc (Val v) @ s; E {{{ l, RET LitV (LitLoc l); l ↦ v ∗ meta_token l ⊤ }}}.
Proof.
iIntros (Φ) "_ HΦ". iApply wp_allocN; auto with lia.
iIntros "!>" (l) "/= (? & ? & _)".
rewrite array_singleton loc_add_0. iApply "HΦ"; iFrame.
Qed.
Lemma twp_alloc s E v :
[[{ True }]] Alloc (Val v) @ s; E [[{ l, RET LitV (LitLoc l); l ↦ v ∗ meta_token l ⊤ }]].
Proof.
iIntros (Φ) "_ HΦ". iApply twp_allocN; auto with lia.
iIntros (l) "/= (? & ? & _)".
rewrite array_singleton loc_add_0. iApply "HΦ"; iFrame.
Qed.
Lemma wp_load s E l q v :
{{{ ▷ l ↦{q} v }}} Load (Val $ LitV $ LitLoc l) @ s; E {{{ RET v; l ↦{q} v }}}.
Proof.
iIntros (Φ) ">Hl HΦ". iApply wp_lift_atomic_head_step_no_fork; auto.
iIntros (σ1 κ κs n) "[Hσ Hκs] !>". iDestruct (@gen_heap_valid with "Hσ Hl") as %?.
iSplit; first by eauto. iNext; iIntros (v2 σ2 efs Hstep); inv_head_step.
iModIntro; iSplit=> //. iFrame. by iApply "HΦ".
Qed.
Lemma twp_load s E l q v :
[[{ l ↦{q} v }]] Load (Val $ LitV $ LitLoc l) @ s; E [[{ RET v; l ↦{q} v }]].
Proof.
iIntros (Φ) "Hl HΦ". iApply twp_lift_atomic_head_step_no_fork; auto.
iIntros (σ1 κs n) "[Hσ Hκs] !>". iDestruct (@gen_heap_valid with "Hσ Hl") as %?.
iSplit; first by eauto. iIntros (κ v2 σ2 efs Hstep); inv_head_step. iModIntro; iSplit=> //. iSplit; first done. iFrame. by iApply "HΦ".
Qed.
Lemma wp_store s E l v' v :
{{{ ▷ l ↦ v' }}} Store (Val $ LitV (LitLoc l)) (Val v) @ s; E
{{{ RET LitV LitUnit; l ↦ v }}}.
Proof.
iIntros (Φ) ">Hl HΦ".
iApply wp_lift_atomic_head_step_no_fork; auto.
iIntros (σ1 κ κs n) "[Hσ Hκs] !>". iDestruct (@gen_heap_valid with "Hσ Hl") as %?.
iSplit; first by eauto. iNext; iIntros (v2 σ2 efs Hstep); inv_head_step.
iMod (@gen_heap_update with "Hσ Hl") as "[$ Hl]".
iModIntro. iSplit=>//. iFrame. by iApply "HΦ".
Qed.
Lemma twp_store s E l v' v :
[[{ l ↦ v' }]] Store (Val $ LitV $ LitLoc l) (Val v) @ s; E
[[{ RET LitV LitUnit; l ↦ v }]].
Proof.
iIntros (Φ) "Hl HΦ".
iApply twp_lift_atomic_head_step_no_fork; auto.
iIntros (σ1 κs n) "[Hσ Hκs] !>". iDestruct (@gen_heap_valid with "Hσ Hl") as %?.
iSplit; first by eauto. iIntros (κ v2 σ2 efs Hstep); inv_head_step.
iMod (@gen_heap_update with "Hσ Hl") as "[$ Hl]".
iModIntro. iSplit=>//. iSplit; first done. iFrame. by iApply "HΦ".
Qed.
Lemma wp_cas_fail s E l q v' v1 v2 :
val_for_compare v' ≠ val_for_compare v1 → vals_cas_compare_safe v' v1 →
{{{ ▷ l ↦{q} v' }}} CAS (Val $ LitV $ LitLoc l) (Val v1) (Val v2) @ s; E
{{{ RET v'; l ↦{q} v' }}}.
Proof.
iIntros (?? Φ) ">Hl HΦ". iApply wp_lift_atomic_head_step_no_fork; auto.
iIntros (σ1 κ κs n) "[Hσ Hκs] !>". iDestruct (@gen_heap_valid with "Hσ Hl") as %?.
iSplit; first by eauto. iNext; iIntros (v2' σ2 efs Hstep); inv_head_step.
iModIntro; iSplit=> //. iFrame. by iApply "HΦ".
Qed.
Lemma twp_cas_fail s E l q v' v1 v2 :
val_for_compare v' ≠ val_for_compare v1 → vals_cas_compare_safe v' v1 →
[[{ l ↦{q} v' }]] CAS (Val $ LitV $ LitLoc l) (Val v1) (Val v2) @ s; E
[[{ RET v'; l ↦{q} v' }]].
Proof.
iIntros (?? Φ) "Hl HΦ". iApply twp_lift_atomic_head_step_no_fork; auto.
iIntros (σ1 κs n) "[Hσ Hκs] !>". iDestruct (@gen_heap_valid with "Hσ Hl") as %?.
iSplit; first by eauto. iIntros (κ v2' σ2 efs Hstep); inv_head_step.
iModIntro; iSplit=> //. iSplit; first done. iFrame. by iApply "HΦ".
Qed.
Lemma wp_cas_suc s E l v1 v2 v' :
val_for_compare v' = val_for_compare v1 → vals_cas_compare_safe v' v1 →
{{{ ▷ l ↦ v' }}} CAS (Val $ LitV $ LitLoc l) (Val v1) (Val v2) @ s; E
{{{ RET v'; l ↦ v2 }}}.
Proof.
iIntros (?? Φ) ">Hl HΦ". iApply wp_lift_atomic_head_step_no_fork; auto.
iIntros (σ1 κ κs n) "[Hσ Hκs] !>". iDestruct (@gen_heap_valid with "Hσ Hl") as %?.
iSplit; first by eauto. iNext; iIntros (v2' σ2 efs Hstep); inv_head_step.
iMod (@gen_heap_update with "Hσ Hl") as "[$ Hl]".
iModIntro. iSplit=>//. iFrame. by iApply "HΦ".
Qed.
Lemma twp_cas_suc s E l v1 v2 v' :
val_for_compare v' = val_for_compare v1 → vals_cas_compare_safe v' v1 →
[[{ l ↦ v' }]] CAS (Val $ LitV $ LitLoc l) (Val v1) (Val v2) @ s; E
[[{ RET v'; l ↦ v2 }]].
Proof.
iIntros (?? Φ) "Hl HΦ". iApply twp_lift_atomic_head_step_no_fork; auto.
iIntros (σ1 κs n) "[Hσ Hκs] !>". iDestruct (@gen_heap_valid with "Hσ Hl") as %?.
iSplit; first by eauto. iIntros (κ v2' σ2 efs Hstep); inv_head_step.
iMod (@gen_heap_update with "Hσ Hl") as "[$ Hl]".
iModIntro. iSplit=>//. iSplit; first done. iFrame. by iApply "HΦ".
Qed.
Lemma wp_faa s E l i1 i2 :
{{{ ▷ l ↦ LitV (LitInt i1) }}} FAA (Val $ LitV $ LitLoc l) (Val $ LitV $ LitInt i2) @ s; E
{{{ RET LitV (LitInt i1); l ↦ LitV (LitInt (i1 + i2)) }}}.
Proof.
iIntros (Φ) ">Hl HΦ". iApply wp_lift_atomic_head_step_no_fork; auto.
iIntros (σ1 κ κs n) "[Hσ Hκs] !>". iDestruct (@gen_heap_valid with "Hσ Hl") as %?.
iSplit; first by eauto. iNext; iIntros (v2' σ2 efs Hstep); inv_head_step.
iMod (@gen_heap_update with "Hσ Hl") as "[$ Hl]".
iModIntro. iSplit=>//. iFrame. by iApply "HΦ".
Qed.
Lemma twp_faa s E l i1 i2 :
[[{ l ↦ LitV (LitInt i1) }]] FAA (Val $ LitV $ LitLoc l) (Val $ LitV $ LitInt i2) @ s; E
[[{ RET LitV (LitInt i1); l ↦ LitV (LitInt (i1 + i2)) }]].
Proof.
iIntros (Φ) "Hl HΦ". iApply twp_lift_atomic_head_step_no_fork; auto.
iIntros (σ1 κs n) "[Hσ Hκs] !>". iDestruct (@gen_heap_valid with "Hσ Hl") as %?.
iSplit; first by eauto. iIntros (κ e2 σ2 efs Hstep); inv_head_step.
iMod (@gen_heap_update with "Hσ Hl") as "[$ Hl]".
iModIntro. iSplit=>//. iSplit; first done. iFrame. by iApply "HΦ".
Qed.
Lemma wp_new_proph s E :
{{{ True }}}
NewProph @ s; E
{{{ pvs p, RET (LitV (LitProphecy p)); proph p pvs }}}.
Proof.
iIntros (Φ) "_ HΦ". iApply wp_lift_atomic_head_step_no_fork; auto.
iIntros (σ1 κ κs n) "[Hσ HR] !>". iSplit; first by eauto.
iNext; iIntros (v2 σ2 efs Hstep). inv_head_step.
iMod (proph_map_new_proph p with "HR") as "[HR Hp]"; first done.
iModIntro; iSplit=> //. iFrame. by iApply "HΦ".
Qed.
(* In the following, strong atomicity is required due to the fact that [e] must
be able to make a head step for [Resolve e _ _] not to be (head) stuck. *)
Lemma resolve_reducible e σ p v :
Atomic StronglyAtomic e → reducible e σ →
reducible (Resolve e (Val (LitV (LitProphecy p))) (Val v)) σ.
Proof.
intros A (κ & e' & σ' & efs & H).
exists (κ ++ [(p, (default v (to_val e'), v))]), e', σ', efs.
eapply Ectx_step with (K:=[]); try done.
assert (∃w, Val w = e') as [w <-].
{ unfold Atomic in A. apply (A σ e' κ σ' efs) in H. unfold is_Some in H.
destruct H as [w H]. exists w. simpl in H. by apply (of_to_val _ _ H). }
simpl. constructor. by apply prim_step_to_val_is_head_step.
Qed.
Lemma step_resolve e p v σ1 κ e2 σ2 efs :
Atomic StronglyAtomic e →
prim_step (Resolve e (Val p) (Val v)) σ1 κ e2 σ2 efs →
head_step (Resolve e (Val p) (Val v)) σ1 κ e2 σ2 efs.
Proof.
intros A [Ks e1' e2' Hfill -> step]. simpl in *.
induction Ks as [|K Ks _] using rev_ind.
+ simpl in *. subst. inversion step. by constructor.
+ rewrite fill_app /= in Hfill. destruct K; inversion Hfill; subst; clear Hfill.
- assert (fill_item K (fill Ks e1') = fill (Ks ++ [K]) e1') as Eq1;
first by rewrite fill_app.
assert (fill_item K (fill Ks e2') = fill (Ks ++ [K]) e2') as Eq2;
first by rewrite fill_app.
rewrite fill_app /=. rewrite Eq1 in A.
assert (is_Some (to_val (fill (Ks ++ [K]) e2'))) as H.
{ apply (A σ1 _ κ σ2 efs). eapply Ectx_step with (K0 := Ks ++ [K]); done. }
destruct H as [v H]. apply to_val_fill_some in H. by destruct H, Ks.
- assert (to_val (fill Ks e1') = Some p); first by rewrite -H1 //.
apply to_val_fill_some in H. destruct H as [-> ->]. inversion step.
- assert (to_val (fill Ks e1') = Some v); first by rewrite -H2 //.
apply to_val_fill_some in H. destruct H as [-> ->]. inversion step.Qed.
Lemma wp_resolve s E e Φ p v pvs :
Atomic StronglyAtomic e →
to_val e = None →
proph p pvs -∗
WP e @ s; E {{ r, ∀ pvs', ⌜pvs = (r, v)::pvs'⌝ -∗ proph p pvs' -∗ Φ r }} -∗
WP Resolve e (Val $ LitV $ LitProphecy p) (Val v) @ s; E {{ Φ }}.
Proof.
(* TODO we should try to use a generic lifting lemma (and avoid [wp_unfold])
here, since this breaks the WP abstraction. *)
iIntros (A He) "Hp WPe". rewrite !wp_unfold /wp_pre /= He. simpl in *.
iIntros (σ1 κ κs n) "[Hσ Hκ]". destruct κ as [|[p' [w' v']] κ' _] using rev_ind.
- iMod ("WPe" $! σ1 [] κs n with "[$Hσ $Hκ]") as "[Hs WPe]". iModIntro. iSplit.
{ iDestruct "Hs" as "%". iPureIntro. destruct s; [ by apply resolve_reducible | done]. }
iIntros (e2 σ2 efs step). exfalso. apply step_resolve in step; last done.
inversion step. match goal with H: ?κs ++ [_] = [] |- _ => by destruct κs end.
- rewrite -app_assoc.
iMod ("WPe" $! σ1 _ _ n with "[$Hσ $Hκ]") as "[Hs WPe]". iModIntro. iSplit.
{ iDestruct "Hs" as %?. iPureIntro. destruct s; [ by apply resolve_reducible | done]. }
iIntros (e2 σ2 efs step). apply step_resolve in step; last done.
inversion step; simplify_list_eq.
iMod ("WPe" $! (Val w') σ2 efs with "[%]") as "WPe".
{ by eexists [] _ _. }
iModIntro. iNext. iMod "WPe" as "[[$ Hκ] WPe]".
iMod (proph_map_resolve_proph p' (w',v') κs with "[$Hκ $Hp]") as (vs' ->) "[$ HPost]".
iModIntro. rewrite !wp_unfold /wp_pre /=. iDestruct "WPe" as "[HΦ $]".
iMod "HΦ". iModIntro. by iApply "HΦ".
Qed.
Lemma wp_resolve_proph s E p pvs v :
{{{ proph p pvs }}}
ResolveProph (Val $ LitV $ LitProphecy p) (Val v) @ s; E
{{{ pvs', RET (LitV LitUnit); ⌜pvs = (LitV LitUnit, v)::pvs'⌝ ∗ proph p pvs' }}}.
Proof.
iIntros (Φ) "Hp HΦ". iApply (wp_resolve with "Hp"); first done.
iApply wp_pure_step_later=> //=. iApply wp_value.
iIntros "!>" (vs') "HEq Hp". iApply "HΦ". iFrame.
Qed.
Lemma wp_allocN_vec s E v n :
0 < n →
{{{ True }}}
AllocN #n v @ s ; E
{{{ l, RET #l; l ↦∗ vreplicate (Z.to_nat n) v ∗
[∗ list] i ∈ seq 0 (Z.to_nat n), meta_token (l +ₗ (i : nat)) ⊤ }}}.
Proof.
iIntros (Hzs Φ) "_ HΦ". iApply wp_allocN; [ lia | done | .. ]. iNext.
iIntros (l) "[Hl Hm]". iApply "HΦ". rewrite vec_to_list_replicate. iFrame.
Qed.
Lemma wp_load_offset s E l off vs v :
vs !! off = Some v →
{{{ ▷ l ↦∗ vs }}} ! #(l +ₗ off) @ s; E {{{ RET v; l ↦∗ vs }}}.
Proof.
iIntros (Hlookup Φ) "Hl HΦ".
iDestruct (update_array l _ _ _ Hlookup with "Hl") as "[Hl1 Hl2]".
iApply (wp_load with "Hl1"). iIntros "!> Hl1". iApply "HΦ".
iDestruct ("Hl2" $! v) as "Hl2". rewrite list_insert_id; last done.
iApply "Hl2". iApply "Hl1".
Qed.
Lemma wp_load_offset_vec s E l sz (off : fin sz) (vs : vec val sz) :
{{{ ▷ l ↦∗ vs }}} ! #(l +ₗ off) @ s; E {{{ RET (vs !!! off); l ↦∗ vs }}}.
Proof. apply wp_load_offset. by apply vlookup_lookup. Qed.
Lemma wp_store_offset s E l off vs v :
is_Some (vs !! off) →
{{{ ▷ l ↦∗ vs }}} #(l +ₗ off) <- v @ s; E {{{ RET #(); l ↦∗ <[off:=v]> vs }}}.
Proof. iIntros ([w Hlookup] Φ) ">Hl HΦ".
iDestruct (update_array l _ _ _ Hlookup with "Hl") as "[Hl1 Hl2]".
iApply (wp_store with "Hl1"). iNext. iIntros "Hl1".
iApply "HΦ". iApply "Hl2". iApply "Hl1".
Qed.
Lemma wp_store_offset_vec s E l sz (off : fin sz) (vs : vec val sz) v :
{{{ ▷ l ↦∗ vs }}} #(l +ₗ off) <- v @ s; E {{{ RET #(); l ↦∗ vinsert off v vs }}}.
Proof.
setoid_rewrite vec_to_list_insert. apply wp_store_offset.
eexists. by apply vlookup_lookup.
Qed.
Lemma wp_cas_suc_offset s E l off vs v' v1 v2 :
vs !! off = Some v' →
val_for_compare v' = val_for_compare v1 →
vals_cas_compare_safe v' v1 →
{{{ ▷ l ↦∗ vs }}}
CAS #(l +ₗ off) v1 v2 @ s; E
{{{ RET v'; l ↦∗ <[off:=v2]> vs }}}.
Proof.
iIntros (Hlookup ?? Φ) "Hl HΦ".
iDestruct (update_array l _ _ _ Hlookup with "Hl") as "[Hl1 Hl2]".
iApply (wp_cas_suc with "Hl1"); [done..|].
iNext. iIntros "Hl1". iApply "HΦ". iApply "Hl2". iApply "Hl1".
Qed.
Lemma wp_cas_suc_offset_vec s E l sz (off : fin sz) (vs : vec val sz) v1 v2 :
val_for_compare (vs !!! off) = val_for_compare v1 →
vals_cas_compare_safe (vs !!! off) v1 →
{{{ ▷ l ↦∗ vs }}}
CAS #(l +ₗ off) v1 v2 @ s; E
{{{ RET (vs !!! off); l ↦∗ vinsert off v2 vs }}}.
Proof.
intros. setoid_rewrite vec_to_list_insert. eapply wp_cas_suc_offset=> //.
by apply vlookup_lookup.
Qed.
Lemma wp_cas_fail_offset s E l off vs v0 v1 v2 :
vs !! off = Some v0 →
val_for_compare v0 ≠ val_for_compare v1 →
vals_cas_compare_safe v0 v1 →
{{{ ▷ l ↦∗ vs }}}
CAS #(l +ₗ off) v1 v2 @ s; E
{{{ RET v0; l ↦∗ vs }}}.
Proof.
iIntros (Hlookup HNEq Hcmp Φ) ">Hl HΦ".
iDestruct (update_array l _ _ _ Hlookup with "Hl") as "[Hl1 Hl2]".
iApply (wp_cas_fail with "Hl1"); first done.
{ destruct Hcmp; by [ left | right ]. }
iIntros "!> Hl1". iApply "HΦ". iDestruct ("Hl2" $! v0) as "Hl2".
rewrite list_insert_id; last done. iApply "Hl2". iApply "Hl1".
Qed.
Lemma wp_cas_fail_offset_vec s E l sz (off : fin sz) (vs : vec val sz) v1 v2 :
val_for_compare (vs !!! off) ≠ val_for_compare v1 →
vals_cas_compare_safe (vs !!! off) v1 →
{{{ ▷ l ↦∗ vs }}}
CAS #(l +ₗ off) v1 v2 @ s; E
{{{ RET (vs !!! off); l ↦∗ vs }}}.
Proof. intros. eapply wp_cas_fail_offset=> //. by apply vlookup_lookup. Qed.
Lemma wp_faa_offset s E l off vs (i1 i2 : Z) :
vs !! off = Some #i1 →
{{{ ▷ l ↦∗ vs }}} FAA #(l +ₗ off) #i2 @ s; E
{{{ RET LitV (LitInt i1); l ↦∗ <[off:=#(i1 + i2)]> vs }}}.
Proof.
iIntros (Hlookup Φ) "Hl HΦ".
iDestruct (update_array l _ _ _ Hlookup with "Hl") as "[Hl1 Hl2]".
iApply (wp_faa with "Hl1"). iNext. iIntros "Hl1". iApply "HΦ". iApply "Hl2". iApply "Hl1".
Qed.
Lemma wp_faa_offset_vec s E l sz (off : fin sz) (vs : vec val sz) (i1 i2 : Z) :
vs !!! off = #i1 →
{{{ ▷ l ↦∗ vs }}} FAA #(l +ₗ off) #i2 @ s; E
{{{ RET LitV (LitInt i1); l ↦∗ vinsert off #(i1 + i2) vs }}}.
Proof.
intros. setoid_rewrite vec_to_list_insert. apply wp_faa_offset=> //.
by apply vlookup_lookup.
Qed.
End lifting.