Section FineGrainedExecutions.
Context
{Sem : Semantics}
{initU : seq.seq nat}
{SemAx : CoreLanguage.SemAxioms}.
Existing Instance dryResources.
Existing Instance HybridFineMachine.scheduler.
Existing Instance OrdinalPool.OrdinalThreadPool.
Existing Instance DryHybridMachineSig.
Existing Instance FineDilMem.
Existing Instance dryFineMach.
(** A location that the machine has no access to (i.e. the permission is empty in all its resources) *)
Inductive deadLocation tp m b ofs : Prop :=
| Dead: forall
(Hvalid: Mem.valid_block m b)
(Hthreads: forall i (cnti: containsThread tp i),
(getThreadR cnti).1 !! b ofs = None /\ (getThreadR cnti).2 !! b ofs = None)
(Hresources: forall l pmap,
lockRes tp l = Some pmap ->
pmap.1 !! b ofs = None /\ pmap.2 !! b ofs = None),
deadLocation tp m b ofs.
(** ** Properties of specific stepss and executions *)
(** [True] whenever some resource in [tp] has above [Readable] lock-permission on [laddr]*)
(* I could not prove the stronger version, where quantification happens inside each case*)
Definition isLock tp laddr :=
forall ofs, Intv.In ofs (laddr.2, laddr.2 + lksize.LKSIZE)%Z ->
(exists i (cnti: containsThread tp i),
Mem.perm_order'' ((getThreadR cnti).2 !! (laddr.1) ofs) (Some Readable)) \/
(exists laddr' rmap, lockRes tp laddr' = Some rmap /\
Mem.perm_order'' (rmap.2 !! (laddr.1) ofs) (Some Readable)).
(*TODO: Move to ev_semantics*)
Definition in_free_list (b : block) ofs xs :=
exists x, List.In x xs /\
let '(b', lo, hi) := x in
b = b' /\
(lo <= ofs < hi)%Z.
Fixpoint in_free_list_trace (b : block) ofs es :=
match es with
| event_semantics.Free l :: es =>
in_free_list b ofs l \/ in_free_list_trace b ofs es
| _ :: es =>
in_free_list_trace b ofs es
| [:: ] =>
False
end.
(** Either the location was freed*)
(** or it wasn't and the operation denoted by the event implies the permission*)
(** or it wasn't and the operation denoted by the event implies the permission*)
(** *** Properties about permission decay and events *)

(** Lifting [lock_permission_decrease_step] to multiple steps using [multi_step] *)
Lemma lock_permission_decrease_execution:
forall U tr tpi mi U' tr' tpj mj
b ofs tidn
(cnti: containsThread tpi tidn)
(cntj: containsThread tpj tidn)
(Hexec: multi_step (U, tr, tpi) mi (U', tr ++ tr', tpj) mj)
(Hperm: Mem.perm_order'' ((getThreadR cnti).2 !! b ofs) (Some Readable))
(Hperm: ~ Mem.perm_order'' ((getThreadR cntj).2 !! b ofs) (Some Readable)),
exists tr_pre tru U'' U''' tp_pre m_pre tp_dec m_dec,
multi_step (U, tr, tpi) mi (U'', tr ++ tr_pre, tp_pre) m_pre /\
MachStep (U'', tr ++ tr_pre, tp_pre) m_pre
(U''', tr ++ tr_pre ++ tru, tp_dec) m_dec /\
multi_step (U''', tr ++ tr_pre ++ tru, tp_dec) m_dec
(U', tr ++ tr',tpj) mj /\
(exists evu,
(List.In evu tru /\ action evu = Free /\ deadLocation tpj mj b ofs) \/
(tru = [:: evu] /\ action evu = Spawn) \/
(tru = [:: evu] /\ action evu = Freelock /\ thread_id evu = tidn /\
match location evu with
| Some (addr, sz) =>
b = addr.1 /\
Intv.In ofs (addr.2, addr.2 + (Z.of_nat sz))%Z
| None => False
end) \/
(tru = [:: evu] /\ action evu = Release /\ thread_id evu = tidn /\
(exists rmap, match location evu with
| Some (laddr, sz) =>
sz = lksize.LKSIZE_nat /\
lockRes tp_dec laddr = Some rmap /\
Mem.perm_order'' (rmap.2 !! b ofs) (Some Readable)
| None => False
end))).