Commit de653fa6 authored by Ralf Jung's avatar Ralf Jung
Browse files

add a client to the atomic increment

parent 504296c5
......@@ -24,21 +24,21 @@ Structure atomic_heap {Σ} `{!heapG Σ} := AtomicHeap {
atomic_wp (load #l)%E
(λ '(v, q), mapsto l q v)
(λ '(v, q) (_:()), mapsto l q v)
(λ '(v, q) _, v);
store_spec (l : loc) (e : expr) (w : val) :
IntoVal e w
atomic_wp (store (#l, e))%E
(λ v, mapsto l 1 v)
(λ v (_:()), mapsto l 1 w)
(λ _ _, #()%V);
cas_spec (l : loc) (e1 e2 : expr) (w1 w2 : val) :
IntoVal e1 w1 IntoVal e2 w2
atomic_wp (cas (#l, e1, e2))%E
(λ v, mapsto l 1 v)
(λ v (_:()), if decide (v = w1) then mapsto l 1 w2 else mapsto l 1 v)
(λ v _, #(if decide (v = w1) then true else false)%V);
}.
Arguments atomic_heap _ {_}.
......@@ -66,7 +66,7 @@ Section proof.
atomic_wp (primitive_load #l)%E
(λ '(v, q), l {q} v)%I
(λ '(v, q) (_:()), l {q} v)%I
(λ '(v, q) _, v).
Proof.
iIntros (Φ) "Aupd". wp_let.
......@@ -79,7 +79,7 @@ Section proof.
atomic_wp (primitive_store (#l, e))%E
(λ v, l v)%I
(λ v (_:()), l w)%I
(λ _ _, #()%V).
Proof.
iIntros (<-%of_to_val Φ) "Aupd". wp_let. wp_proj. wp_proj.
......@@ -92,7 +92,7 @@ Section proof.
atomic_wp (primitive_cas (#l, e1, e2))%E
(λ v, l v)%I
(λ v (_:()), if decide (v = w1) then l w2 else l v)%I
(λ v _, #(if decide (v = w1) then true else false)%V).
Proof.
iIntros (<-%of_to_val <-%of_to_val Φ) "Aupd". wp_let. repeat wp_proj.
......
......@@ -2,7 +2,7 @@ From iris.heap_lang Require Export lifting notation.
From iris.base_logic.lib Require Export invariants.
From iris.program_logic Require Export atomic.
From iris.proofmode Require Import tactics.
From iris.heap_lang Require Import proofmode notation atomic_heap.
From iris.heap_lang Require Import proofmode notation atomic_heap par.
Set Default Proof Using "Type".
(** Show taht implementing fetch-and-add on top of CAS preserves logical
......@@ -10,7 +10,7 @@ atomicity. *)
(* TODO: Move this to iris-examples once gen_proofmode is merged. *)
Section increment.
Context `{!heapG Σ} {aheap: atomic_heap Σ}.
Context `{!heapG Σ} (aheap: atomic_heap Σ).
Definition incr: val :=
rec: "incr" "l" :=
......@@ -23,7 +23,7 @@ Section increment.
atomic_wp (incr #l)
(λ (v: Z), aheap.(mapsto) l 1 #v)%I
(λ v (_:()), aheap.(mapsto) l 1 #(v + 1))%I
(λ v _, #v).
Proof.
iIntros (Φ) "AUpd". iLöb as "IH". wp_let.
......@@ -56,3 +56,40 @@ Section increment.
End increment.
Section increment_client.
Context `{!heapG Σ, !spawnG Σ}.
Definition incr_client : val :=
λ: "x",
let: "l" := ref "x" in
incr primitive_atomic_heap "l" ||| incr primitive_atomic_heap "l".
Lemma incr_client_safe (x: Z):
WP incr_client #x {{ _, True }}%I.
Proof using Type*.
wp_let. wp_alloc l as "Hl". wp_let.
iMod (inv_alloc nroot _ (x':Z, l #x')%I with "[Hl]") as "#?"; first eauto.
(* FIXME: I am only usign persistent stuff, so I should be allowed
to move this to the persisten context even without the additional □. *)
iAssert ( atomic_update (λ (v: Z), l #v)
(λ v (_:()), l #(v + 1))
(λ _ _, True))%I as "#Aupd".
{ iAlways. iExists True%I, True%I. repeat (iSplit; first done). clear x.
iIntros (E) "!# % _".
assert (E = ) as -> by set_solver.
iInv nroot as (x) ">H↦" "Hclose".
iMod fupd_intro_mask' as "Hclose2"; last iModIntro; first set_solver.
iExists _. iFrame. iSplit.
{ iIntros "H↦". iMod "Hclose2" as "_". iMod ("Hclose" with "[-]"); last done.
iNext. iExists _. iFrame. }
iIntros (_) "H↦". iMod "Hclose2" as "_".
iMod ("Hclose" with "[-]"); last done. iNext. iExists _. iFrame. }
wp_apply (wp_par (λ _, True)%I (λ _, True)%I).
- wp_apply incr_spec. iAssumption. (* FIXME: without giving the
postconditions above, this diverges. *)
- wp_apply incr_spec. iAssumption.
- iIntros (??) "_ !>". done.
Qed.
End increment_client.
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