SessionTypes: a fuller multiparty example

This commit is contained in:
Adam Chlipala 2018-05-13 18:38:58 -04:00
parent a86ecf84ad
commit 1fdf19f4f0

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@ -274,7 +274,7 @@ Section parties.
| HtRecv : forall mayNotSend ch sr (A : Set) (k : A -> _) t (witness : A),
channels ch = {| Sender := sr; Receiver := p |}
-> sr <> p
-> (forall v, hasty p mayNotSend (k v) (t v))
-> (forall v, hasty p false (k v) (t v))
-> hasty p mayNotSend (Recv ch k) (Communicate ch t)
| HtSkip : forall mayNotSend ch sr rr (A : Set) pr (t : A -> _) (witness : A),
channels ch = {| Sender := sr; Receiver := rr |}
@ -286,6 +286,7 @@ Section parties.
hasty p mayNotSend Done TDone.
End parties.
(** * Parallel execution preserves the existence of complementary session types. *)
Definition trsys_of pr := {|
@ -378,6 +379,32 @@ Inductive typed_multistate party (channels : channel -> parties party) (t : type
Hint Constructors typed_multistate.
Ltac side :=
match goal with
| [ |- ?E = {| Sender := _; Receiver := _ |} ] =>
let E' := eval hnf in E in change E with E';
repeat match goal with
| [ |- context[if ?E then _ else _] ] => cases E; try (exfalso; equality)
end;
try (exfalso; equality);
repeat match goal with
| [ H : NoDup _ |- _ ] => invert H
end; simplify; try (exfalso; equality); equality
| [ |- _ <> _ ] => equality
end.
Ltac hasty := simplify; repeat match goal with
| [ |- typed_multistate _ _ _ _ ] => econstructor; simplify
| [ |- hasty _ _ _ _ _ ] =>
apply HtDone
|| (eapply HtSend; [ side | side | ])
|| (eapply HtRecv; [ constructor | side | side | simplify ])
|| (eapply HtSkip; [ constructor | side | side | side | simplify ])
| [ |- hasty _ _ _ _ (match ?E with _ => _ end) ] => cases E
| [ |- hasty _ _ _ (match ?E with _ => _ end) _ ] => cases E
end.
Lemma no_silent_steps : forall party (channels : _ -> parties party) p mns pr t,
hasty channels p mns pr t
-> forall pr', lstep pr Silent pr'
@ -415,7 +442,6 @@ Proof.
induct 1; eauto; invert 1.
Unshelve.
assumption.
assumption.
Qed.
Hint Immediate mayNotSend_really.
@ -1014,31 +1040,6 @@ Section online_store.
{| Sender := Merchant;
Receiver := Customer |}.
Ltac side :=
match goal with
| [ |- ?E = {| Sender := _; Receiver := _ |} ] =>
let E' := eval hnf in E in change E with E';
repeat match goal with
| [ |- context[if ?E then _ else _] ] => cases E; try equality
end;
try equality;
repeat match goal with
| [ H : NoDup _ |- _ ] => invert H
end; simplify; equality
| [ |- _ <> _ ] => equality
end.
Ltac hasty := simplify; repeat match goal with
| [ |- typed_multistate _ _ _ _ ] => econstructor; simplify
| [ |- hasty _ _ _ _ _ ] =>
apply HtDone
|| (eapply HtSend; [ side | side | ])
|| (eapply HtRecv; [ constructor | side | side | simplify ])
|| (eapply HtSkip; [ constructor | side | side | side | ])
| [ |- hasty _ _ _ _ (match ?E with _ => _ end) ] => cases E
| [ |- hasty _ _ _ (match ?E with _ => _ end) _ ] => cases E
end.
Example online_store_no_deadlock : forall product payment_info in_stock payment_checker,
NoDup [request_product; in_stock_or_not; send_payment_info; payment_success; add_review]
-> invariantFor (trsys_of (customer product payment_info
@ -1061,4 +1062,110 @@ Section online_store.
Qed.
End online_store.
Inductive store_party' := Customer' | Merchant' | Warehouse.
Section online_store_with_warehouse.
Variables request_product in_stock_or_not send_payment_info payment_success add_review
merchant_to_warehouse warehouse_to_merchant : channel.
Definition customer' (product payment_info : string) :=
!!request_product(product);
??in_stock_or_not(worked : bool);
if worked then
!!send_payment_info(payment_info);
??payment_success(worked_again : bool);
if worked_again then
!!add_review((product, "awesome"));
Done
else
Done
else
Done.
Definition merchant' (payment_checker : string -> bool) :=
??request_product(product : string);
!!merchant_to_warehouse(product);
??warehouse_to_merchant(in_stock : bool);
if in_stock then
!!in_stock_or_not(true);
??send_payment_info(payment_info : string);
if payment_checker payment_info then
!!payment_success(true);
??add_review(_ : (string * string)%type);
Done
else
!!payment_success(false);
Done
else
!!in_stock_or_not(false);
Done.
Definition warehouse (in_stock : string -> bool) :=
??merchant_to_warehouse(product : string);
if in_stock product then
!!warehouse_to_merchant(true);
Done
else
!!warehouse_to_merchant(false);
Done.
Definition online_store_type' :=
(!!!request_product(_ : string);
!!!merchant_to_warehouse(_ : string);
!!!warehouse_to_merchant(_ : bool);
!!!in_stock_or_not(worked : bool);
if worked then
!!!send_payment_info(_ : string);
!!!payment_success(worked_again : bool);
if worked_again then
!!!add_review(_ : (string * string)%type);
TDone
else
TDone
else
TDone)%st.
Definition online_store_channels' (ch : channel) :=
if ch ==n request_product then
{| Sender := Customer';
Receiver := Merchant' |}
else if ch ==n send_payment_info then
{| Sender := Customer';
Receiver := Merchant' |}
else if ch ==n add_review then
{| Sender := Customer';
Receiver := Merchant' |}
else if ch ==n merchant_to_warehouse then
{| Sender := Merchant';
Receiver := Warehouse |}
else if ch ==n warehouse_to_merchant then
{| Sender := Warehouse;
Receiver := Merchant' |}
else
{| Sender := Merchant';
Receiver := Customer' |}.
Example online_store_no_deadlock' : forall product payment_info in_stock good_infos,
NoDup [request_product; in_stock_or_not; send_payment_info; payment_success; add_review;
merchant_to_warehouse; warehouse_to_merchant]
-> invariantFor (trsys_of (customer' product payment_info
|| (merchant' in_stock
|| (warehouse good_infos || Done))))
(fun pr => inert pr
\/ exists pr', lstep pr Silent pr').
Proof.
simplify.
eapply no_deadlock with (t := online_store_type')
(all_parties := [Customer'; Merchant'; Warehouse])
(channels := online_store_channels');
simplify.
repeat constructor; simplify; equality.
cases p; auto.
hasty; constructor.
Qed.
End online_store_with_warehouse.
End Multiparty.