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Add an invariant preserved by dispatch_mut to the Dispatch trait #1

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Add an invariant preserved by dispatch_mut to the Dispatch trait #1

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10 changes: 10 additions & 0 deletions verified-node-replication/src/exec/log.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -706,6 +706,7 @@ impl<DT: Dispatch> NrLog<DT> {
) -> (result: Tracked<NrLogAppendExecDataGhost<DT>>)
requires
self.wf(),
old(actual_replica).inv(),
replica_token@ < self.local_versions.len(),
old(responses).len() == 0,
ghost_data@.append_pre(
Expand All @@ -717,6 +718,7 @@ impl<DT: Dispatch> NrLog<DT> {
),
operations.len() <= MAX_REQUESTS,
ensures
actual_replica.inv(),
result@.append_post(
ghost_data@,
replica_token@,
Expand All @@ -735,6 +737,7 @@ impl<DT: Dispatch> NrLog<DT> {
loop
invariant
self.wf(),
actual_replica.inv(),
0 <= waitgc <= WARN_THRESHOLD,
0 <= iteration <= WARN_THRESHOLD,
responses.len() == 0,
Expand Down Expand Up @@ -1072,6 +1075,7 @@ impl<DT: Dispatch> NrLog<DT> {
) -> (res: Tracked<NrLogAppendExecDataGhost<DT>>)
requires
self.wf(),
old(actual_replica).inv(),
replica_token.wf(self.num_replicas@),
ghost_data@.advance_head_pre(
replica_token.id_spec(),
Expand All @@ -1081,6 +1085,7 @@ impl<DT: Dispatch> NrLog<DT> {
self.cyclic_buffer_instance@,
),
ensures
actual_replica.inv(),
res@.advance_head_post(
ghost_data@,
replica_token.id_spec(),
Expand All @@ -1095,6 +1100,7 @@ impl<DT: Dispatch> NrLog<DT> {
loop
invariant
self.wf(),
actual_replica.inv(),
replica_token.wf(self.num_replicas@),
ghost_data_new@.cb_combiner@@.value.is_Idle(),
ghost_data_new@.combiner@@.value.is_Placed() ==> ghost_data_new@.pre_exec(
Expand Down Expand Up @@ -1264,6 +1270,7 @@ impl<DT: Dispatch> NrLog<DT> {
ghost_data: Tracked<NrLogAppendExecDataGhost<DT>>,
) -> (result: Tracked<NrLogAppendExecDataGhost<DT>>)
requires
old(actual_replica).inv(),
self.wf(),
replica_token@ < self.local_versions.len(),
ghost_data@.execute_pre(
Expand All @@ -1274,6 +1281,7 @@ impl<DT: Dispatch> NrLog<DT> {
self.cyclic_buffer_instance@,
),
ensures
actual_replica.inv(),
result@.execute_post(
ghost_data@,
replica_token@,
Expand Down Expand Up @@ -1370,6 +1378,7 @@ impl<DT: Dispatch> NrLog<DT> {
while local_version < global_tail
invariant
self.wf(),
actual_replica.inv(),
ghost_data.combiner@@.value.is_Placed() ==> {
&&& ghost_data.combiner@@.value.get_Placed_queued_ops() == request_ids
&&& combiner@.value.get_Loop_queued_ops() == request_ids
Expand Down Expand Up @@ -1428,6 +1437,7 @@ impl<DT: Dispatch> NrLog<DT> {
while !is_alive
invariant
self.wf(),
actual_replica.inv(),
local_version < global_tail,
phys_log_idx < self.slog.len(),
phys_log_idx as nat == self.index_spec(local_version as nat),
Expand Down
7 changes: 5 additions & 2 deletions verified-node-replication/src/exec/replica.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -225,7 +225,7 @@ pub open spec fn wf(&self) -> bool {
&&& self.data.0.max_threads() == self.contexts.len()
&&& 0 <= self.spec_id() < MAX_REPLICAS
&&& self.data.0.wf()
&&& (forall |v: ReplicatedDataStructure<DT>| (#[trigger] self.data.0.inv(v)) == v.wf(self.spec_id(), self.unbounded_log_instance@, self.cyclic_buffer_instance@))
&&& (forall |v: ReplicatedDataStructure<DT>| (#[trigger] self.data.0.inv(v)) == (v.wf(self.spec_id(), self.unbounded_log_instance@, self.cyclic_buffer_instance@) && v.data.inv()))

&&& self.flat_combiner_instance@.num_threads() == MAX_THREADS_PER_REPLICA
&&& (forall |i| #![trigger self.thread_tokens[i]] 0 <= i < self.thread_tokens.len() ==> {
Expand Down Expand Up @@ -316,7 +316,10 @@ impl<DT: Dispatch> Replica<DT> {
));
// TODO: get the right spec function in there!
let ghost data_structure_inv = |s: ReplicatedDataStructure<DT>|
{ s.wf(replica_token.id_spec(), unbounded_log_instance, cyclic_buffer_instance) };
{
s.wf(replica_token.id_spec(), unbounded_log_instance, cyclic_buffer_instance)
&& s.data.inv()
};
let data = CachePadded(
RwLock::new(
MAX_THREADS_PER_REPLICA,
Expand Down
9 changes: 9 additions & 0 deletions verified-node-replication/src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -154,6 +154,7 @@ pub trait Dispatch: Sized {
fn init() -> (res: Self)
ensures
res@ == Self::init_spec(),
res.inv(),
;

/// Clones a write operation to be copied to and read from the shared log.
Expand All @@ -170,13 +171,18 @@ pub trait Dispatch: Sized {

/// Executes a read-only operation against the data structure and returns the result.
fn dispatch(&self, op: Self::ReadOperation) -> (result: Self::Response)
requires
self.inv(),
ensures
Self::dispatch_spec(self@, op) == result,
;

/// Executes a write operation against the data structure and returns the result.
fn dispatch_mut(&mut self, op: Self::WriteOperation) -> (result: Self::Response)
requires
old(self).inv(),
ensures
self.inv(),
Self::dispatch_mut_spec(old(self)@, op) == (self@, result),
;

Expand All @@ -191,6 +197,9 @@ pub trait Dispatch: Sized {
Self::View,
Self::Response,
);

/// An invariant that is preserved by [`Dispatch::dispatch_mut`]
spec fn inv(&self) -> bool;
}

////////////////////////////////////////////////////////////////////////////////////////////////////
Expand Down