Merge branch 'hwq' into 'master'

Herlihy-Wing queue example (involving prophecy variables)

See merge request !25

_CoqProject

@@ -110,3 +110,5 @@ theories/logatom/conditional_increment/cinc.v
 theories/logatom/rdcss/rdcss.v
 theories/logatom/rdcss/spec.v
 theories/logatom/proph_erasure.v
+theories/logatom/herlihy_wing_queue/spec.v
+theories/logatom/herlihy_wing_queue/hwq.v

theories/logatom/herlihy_wing_queue/spec.v

+From iris.heap_lang Require Export lifting notation.
+From iris.program_logic Require Export atomic.
+Set Default Proof Using "Type".
+
+(** A general logically atomic interface for Herlihy-Wing queues. *)
+Record atomic_hwq {Σ} `{!heapG Σ} := AtomicHWQ {
+  (* -- operations -- *)
+  new_queue : val;
+  enqueue : val;
+  dequeue : val;
+  (* -- other data -- *)
+  name : Type;
+  name_eqdec : EqDecision name;
+  name_countable : Countable name;
+  (* -- predicates -- *)
+  is_hwq (N : namespace) (sz : nat) (γ : name) (v : val) : iProp Σ;
+  hwq_content (γ : name) (ls : list loc) : iProp Σ;
+  (* -- predicate properties -- *)
+  is_hwq_persistent N sz γ v : Persistent (is_hwq N sz γ v);
+  hwq_content_timeless γ ls : Timeless (hwq_content γ ls);
+  hwq_content_exclusive γ ls1 ls2 :
+    hwq_content γ ls1 -∗ hwq_content γ ls2 -∗ False;
+  (* -- operation specs -- *)
+  new_queue_spec N (sz : nat) :
+    0 < sz →
+    {{{ True }}}
+      new_queue #sz
+    {{{ v γ, RET v; is_hwq N sz γ v ∗ hwq_content γ [] }}};
+  enqueue_spec N (sz : nat) (γ : name) (q : val) (l : loc) :
+    is_hwq N sz γ q -∗
+    <<< ∀ (ls : list loc), hwq_content γ ls >>>
+      enqueue q #l @ ⊤ ∖ ↑N
+    <<< hwq_content γ (ls ++ [l]), RET #() >>>;
+  dequeue_spec N (sz : nat) (γ : name) (q : val) :
+    is_hwq N sz γ q -∗
+    <<< ∀ (ls : list loc), hwq_content γ ls >>>
+      dequeue q @ ⊤ ∖ ↑N
+    <<< ∃ (l : loc) ls', ⌜ls = l :: ls'⌝ ∗ hwq_content γ ls', RET #l >>>;
+}.
+Arguments atomic_hwq _ {_}.
+
+Existing Instances is_hwq_persistent hwq_content_timeless.