Commit 6eee4a54 authored by Robbert Krebbers's avatar Robbert Krebbers

More powerful allocation rule for spin lock. Add deallocation rule for spin_lock.

parent e29d18e2
......@@ -6,7 +6,7 @@ From iris.base_logic.lib Require Import cancelable_invariants.
From iris.bi.lib Require Import fractional.
Set Default Proof Using "Type".
Definition newlock : val := λ: <>, ref #false.
Definition new_lock : val := λ: <>, ref #false.
Definition try_acquire : val := λ: "l", CAS "l" #false #true.
Definition acquire : val :=
rec: "acquire" "l" := if: try_acquire "l" then #() else "acquire" "l".
......@@ -63,21 +63,33 @@ Section proof.
Global Instance unlocked_timeless lk q : Timeless (unlocked lk q).
Proof. apply _. Qed.
Lemma newlock_spec (R : iProp Σ):
{{{ R }}}
newlock #()
{{{ lk, RET #lk; is_lock lk R unlocked lk 1 }}}.
Lemma lock_cancel E lk R : N E is_lock lk R - unlocked lk 1 ={E}= R.
Proof.
iIntros (Φ) "HR HΦ". rewrite -wp_fupd /newlock /=.
wp_lam. wp_apply (wp_alloc with "[//]"); iIntros (l) "[Hl Hm]".
intros. iDestruct 1 as (γ γi) "#[Hm Hinv]". iDestruct 1 as (γ' γi') "[Hm' Hq]".
iDestruct (meta_agree with "Hm Hm'") as %[= <- <-]; iClear "Hm'".
iMod (cinv_open_strong with "[$] [$]") as "(HR & Hq & Hclose)"; first done.
iDestruct "HR" as ([]) "[Hl HR]".
- iDestruct "HR" as (p) "[_ Hq']". iDestruct (cinv_own_1_l with "Hq Hq'") as ">[]".
- iDestruct "HR" as "[_ $]". iApply "Hclose"; auto.
Qed.
Lemma new_lock_spec :
{{{ True }}}
new_lock #()
{{{ lk, RET #lk; unlocked lk 1 ( R, R ={}= is_lock lk R) }}}.
Proof.
iIntros (Φ) "_ HΦ". iApply wp_fupd. wp_lam.
wp_apply (wp_alloc with "[//]"); iIntros (l) "[Hl Hm]".
iDestruct (meta_token_difference _ (N) with "Hm") as "[Hm1 Hm2]"; first done.
iMod (own_alloc ( None)) as (γ) "Hγ"; first by apply auth_auth_valid.
iMod (cinv_alloc_strong (λ _, True))
as (γi _) "[Hγi H]"; first by apply pred_infinite_True.
iMod (meta_set _ _ (γ,γi) with "Hm1") as "#Hm1"; first done.
iApply "HΦ"; iSplitL "Hγi"; first by (iExists γ, γi; auto).
iIntros "!>" (R) "HR".
iMod ("H" $! (lock_inv γ γi l R) with "[HR Hl Hγ]") as "#?".
{ iIntros "!>". iExists false. by iFrame. }
iModIntro. iApply "HΦ". iSplit; iExists γ, γi; auto.
iModIntro. iExists γ, γi; auto.
Qed.
Lemma try_acquire_spec lk R q :
......
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