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Merged
uink45 merged 1 commit into from
Mar 11, 2026
Merged

Use updated finalized slot in attestations #71

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28 changes: 13 additions & 15 deletions src/consensus/state.c
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1716,7 +1716,7 @@ static int lantern_state_process_attestations_internal(

LanternCheckpoint latest_justified = state->latest_justified;
LanternCheckpoint latest_finalized = state->latest_finalized;
uint64_t base_finalized_slot = latest_finalized.slot;
uint64_t finalized_slot = latest_finalized.slot;
double att_batch_start = lantern_time_now_seconds();
size_t att_attempted = 0;
bool finalization_attempted = false;
Expand Down Expand Up @@ -1891,15 +1891,15 @@ static int lantern_state_process_attestations_internal(
continue;
}

/* Target slot must be justifiable after the pre-loop finalized slot snapshot (leanSpec line 410) */
if (!lantern_slot_is_justifiable(vote->target.slot, base_finalized_slot)) {
/* Target slot must remain justifiable after the current finalized slot. */
if (!lantern_slot_is_justifiable(vote->target.slot, finalized_slot)) {
if (trace_finalization) {
lantern_log_debug(
"state",
&meta,
"finalization trace skip non-justifiable target_slot=%" PRIu64 " finalized=%" PRIu64,
vote->target.slot,
base_finalized_slot);
finalized_slot);
}
record_attestation_validation_metric(att_validation_start, true);
continue;
Expand Down Expand Up @@ -1991,14 +1991,11 @@ static int lantern_state_process_attestations_internal(
vote->target.slot);
}

/* Finalization: if the target is the next valid justifiable slot after source (leanSpec lines 435-439)
*
* The gap check is evaluated relative to the pre-loop finalized slot snapshot.
* leanSpec uses self.latest_finalized.slot from the immutable input state for this check,
* so use base_finalized_slot rather than the progressively updated latest_finalized.slot.
/* Finalization: if the target is the next valid justifiable slot after source
* relative to the current finalized boundary, finalize the source checkpoint.
*/
bool has_justifiable_between = has_justifiable_slot_between(
vote->source.slot, vote->target.slot, base_finalized_slot);
vote->source.slot, vote->target.slot, finalized_slot);
bool vote_has_consecutive_source = !has_justifiable_between;

if (trace_finalization) {
Expand All @@ -2016,12 +2013,13 @@ static int lantern_state_process_attestations_internal(

if (vote_has_consecutive_source) {
/* Finalize the source checkpoint */
uint64_t old_finalized_slot = latest_finalized.slot;
uint64_t old_finalized_slot = finalized_slot;
latest_finalized = vote->source;
finalized_slot = latest_finalized.slot;
finalization_attempted = true;
lean_metrics_record_finalization_attempt(true);
if (latest_finalized.slot > old_finalized_slot) {
uint64_t delta = latest_finalized.slot - old_finalized_slot;
if (finalized_slot > old_finalized_slot) {
uint64_t delta = finalized_slot - old_finalized_slot;
if (delta > SIZE_MAX) {
if (finalization_attempted) {
lean_metrics_record_finalization_attempt(false);
Expand All @@ -2041,8 +2039,8 @@ static int lantern_state_process_attestations_internal(
state->latest_finalized = latest_finalized;
if (lantern_state_prune_justification_roots(
state,
base_finalized_slot,
latest_finalized.slot,
old_finalized_slot,
finalized_slot,
validator_count,
&meta)
!= 0) {
Expand Down
203 changes: 195 additions & 8 deletions tests/unit/test_state.c
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1175,6 +1175,187 @@ static int test_attestations_finalize_across_gap(void) {
return 0;
}

static int test_attestations_use_updated_finalized_slot_for_target_justifiability(void) {
LanternState state;
lantern_state_init(&state);
expect_zero(
lantern_state_generate_genesis(&state, 748, 3),
"genesis for updated finalized target-justifiability test");

populate_historical_hashes_for_tests(&state, 9);

state.latest_finalized.slot = 0;
state.latest_finalized.root = get_historical_root_for_tests(&state, 0);
state.latest_justified.slot = 1;
state.latest_justified.root = get_historical_root_for_tests(&state, 1);
mark_slot_justified_for_tests(&state, 1);

LanternCheckpoint first_source = state.latest_justified;
LanternCheckpoint first_target = first_source;
first_target.slot = 2;
first_target.root = get_historical_root_for_tests(&state, first_target.slot);

LanternCheckpoint second_source = first_target;
LanternCheckpoint second_target = second_source;
second_target.slot = 9;
second_target.root = get_historical_root_for_tests(&state, second_target.slot);

LanternAttestations attestations;
lantern_attestations_init(&attestations);
LanternSignatureList signatures;
lantern_signature_list_init(&signatures);
expect_zero(
lantern_attestations_resize(&attestations, 4),
"resize updated finalized target-justifiability attestations");
expect_zero(
lantern_signature_list_resize(&signatures, 4),
"resize updated finalized target-justifiability signatures");

build_vote(
&attestations.data[0],
&signatures.data[0],
0,
first_target.slot,
&first_source,
&first_target,
0xA8);
build_vote(
&attestations.data[1],
&signatures.data[1],
1,
first_target.slot,
&first_source,
&first_target,
0xA9);
build_vote(
&attestations.data[2],
&signatures.data[2],
0,
second_target.slot,
&second_source,
&second_target,
0xAA);
build_vote(
&attestations.data[3],
&signatures.data[3],
1,
second_target.slot,
&second_source,
&second_target,
0xAB);

expect_zero(
lantern_state_process_attestations(&state, &attestations, &signatures),
"process updated finalized target-justifiability attestations");

assert(state.latest_finalized.slot == first_source.slot);
assert(state.latest_justified.slot == first_target.slot);
assert(state.justification_roots.length == 0);

bool target_justified = true;
expect_zero(
lantern_state_get_justified_slot_bit(&state, second_target.slot, &target_justified),
"read skipped target justification bit");
assert(!target_justified);

lantern_attestations_reset(&attestations);
lantern_signature_list_reset(&signatures);
lantern_state_reset(&state);
return 0;
}

static int test_attestations_use_updated_finalized_slot_for_gap_check(void) {
LanternState state;
lantern_state_init(&state);
expect_zero(
lantern_state_generate_genesis(&state, 749, 3),
"genesis for updated finalized gap-check test");

populate_historical_hashes_for_tests(&state, 9);

state.latest_finalized.slot = 0;
state.latest_finalized.root = get_historical_root_for_tests(&state, 0);
state.latest_justified.slot = 3;
state.latest_justified.root = get_historical_root_for_tests(&state, 3);

expect_zero(
lantern_bitlist_resize(&state.justified_slots, 6),
"resize justified slots for updated finalized gap-check test");
assert(state.justified_slots.bytes != NULL);
memset(state.justified_slots.bytes, 0, state.justified_slots.capacity);
mark_slot_justified_for_tests(&state, 3);
mark_slot_justified_for_tests(&state, 6);

LanternCheckpoint first_source = state.latest_justified;
LanternCheckpoint first_target = first_source;
first_target.slot = 4;
first_target.root = get_historical_root_for_tests(&state, first_target.slot);

LanternCheckpoint second_source = first_source;
second_source.slot = 6;
second_source.root = get_historical_root_for_tests(&state, second_source.slot);

LanternCheckpoint second_target = second_source;
second_target.slot = 9;
second_target.root = get_historical_root_for_tests(&state, second_target.slot);

LanternAttestations attestations;
lantern_attestations_init(&attestations);
LanternSignatureList signatures;
lantern_signature_list_init(&signatures);
expect_zero(
lantern_attestations_resize(&attestations, 4),
"resize updated finalized gap-check attestations");
expect_zero(
lantern_signature_list_resize(&signatures, 4),
"resize updated finalized gap-check signatures");

build_vote(
&attestations.data[0],
&signatures.data[0],
0,
first_target.slot,
&first_source,
&first_target,
0xAC);
build_vote(
&attestations.data[1],
&signatures.data[1],
1,
first_target.slot,
&first_source,
&first_target,
0xAD);
build_vote(
&attestations.data[2],
&signatures.data[2],
0,
second_target.slot,
&second_source,
&second_target,
0xAE);
build_vote(
&attestations.data[3],
&signatures.data[3],
1,
second_target.slot,
&second_source,
&second_target,
0xAF);

expect_zero(
lantern_state_process_attestations(&state, &attestations, &signatures),
"process updated finalized gap-check attestations");

assert(state.latest_finalized.slot == first_source.slot);
assert(state.latest_justified.slot == second_target.slot);

lantern_attestations_reset(&attestations);
lantern_signature_list_reset(&signatures);
lantern_state_reset(&state);
return 0;
}

static int test_pruning_keeps_pending_justifications(void) {
LanternState state;
lantern_state_init(&state);
Expand Down Expand Up @@ -1270,7 +1451,7 @@ static int test_pending_votes_survive_interleaved_justification_and_finalization
const uint64_t finalized_slot = 334u;
const uint64_t justified_slot = 340u;
const uint64_t target_justified_slot = 343u;
const uint64_t target_pending_slot = 350u;
const uint64_t target_pending_slot = 346u;
const uint64_t block_slot = 354u;
const uint64_t anchor = finalized_slot + 1u;
const size_t validator_count_sz = (size_t)validator_count;
Expand Down Expand Up @@ -1313,7 +1494,7 @@ static int test_pending_votes_survive_interleaved_justification_and_finalization

/* Pre-slot-354 pending votes:
* root@343 -> validators {0,2,4}
* root@350 -> validators {0,3}
* root@346 -> validators {0,3}
*/
expect_zero(
lantern_bitlist_set(&state.justification_validators, 0, true),
Expand All @@ -1326,10 +1507,10 @@ static int test_pending_votes_survive_interleaved_justification_and_finalization
"seed root@343 vote for validator 4");
expect_zero(
lantern_bitlist_set(&state.justification_validators, validator_count_sz + 0u, true),
"seed root@350 vote for validator 0");
"seed root@346 vote for validator 0");
expect_zero(
lantern_bitlist_set(&state.justification_validators, validator_count_sz + 3u, true),
"seed root@350 vote for validator 3");
"seed root@346 vote for validator 3");

LanternAttestations attestations;
lantern_attestations_init(&attestations);
Expand Down Expand Up @@ -1423,7 +1604,7 @@ static int test_pending_votes_preserved_when_new_root_inserts_before_existing_ro
const uint64_t finalized_slot = 334u;
const uint64_t justified_slot = 340u;
const uint64_t target_justified_slot = 343u;
const uint64_t target_pending_slot = 350u;
const uint64_t target_pending_slot = 346u;
const uint64_t anchor = finalized_slot + 1u;
const size_t validator_count_sz = (size_t)validator_count;

Expand Down Expand Up @@ -1456,7 +1637,7 @@ static int test_pending_votes_preserved_when_new_root_inserts_before_existing_ro
LanternSignatureList signatures;
lantern_signature_list_init(&signatures);

/* Step 1: create pending root@350 with votes {0,3}. */
/* Step 1: create pending root@346 with votes {0,3}. */
expect_zero(lantern_attestations_resize(&attestations, 2), "resize step1 attestations");
expect_zero(lantern_signature_list_resize(&signatures, 2), "resize step1 signatures");
build_vote(
Expand All @@ -1479,7 +1660,7 @@ static int test_pending_votes_preserved_when_new_root_inserts_before_existing_ro
lantern_state_process_attestations(&state, &attestations, &signatures),
"process insertion-order step1");

/* Step 2: add root@343 with votes {0,2,4}. This must insert before root@350. */
/* Step 2: add root@343 with votes {0,2,4}. This must insert before root@346. */
expect_zero(lantern_attestations_resize(&attestations, 3), "resize step2 attestations");
expect_zero(lantern_signature_list_resize(&signatures, 3), "resize step2 signatures");
build_vote(
Expand Down Expand Up @@ -1510,7 +1691,7 @@ static int test_pending_votes_preserved_when_new_root_inserts_before_existing_ro
lantern_state_process_attestations(&state, &attestations, &signatures),
"process insertion-order step2");

/* Step 3: justify root@343 and add one more vote to root@350. */
/* Step 3: justify root@343 and add one more vote to root@346. */
expect_zero(lantern_attestations_resize(&attestations, 2), "resize step3 attestations");
expect_zero(lantern_signature_list_resize(&signatures, 2), "resize step3 signatures");
build_vote(
Expand Down Expand Up @@ -3237,6 +3418,12 @@ int main(void) {
if (test_attestations_finalize_across_gap() != 0) {
return 1;
}
if (test_attestations_use_updated_finalized_slot_for_target_justifiability() != 0) {
return 1;
}
if (test_attestations_use_updated_finalized_slot_for_gap_check() != 0) {
return 1;
}
if (test_pruning_keeps_pending_justifications() != 0) {
return 1;
}
Expand Down
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