Replace INTERVALS_PER_SLOT with explicit slot component times (#4476)

This PR is an alternative to #3510.

* Deprecate `SECONDS_PER_SLOT` in favor of `SLOT_DURATION_MS`.
* Deprecate `INTERVALS_PER_SLOT` in favor of config vars in basis points.

Instead of presets in millisecond units, this PR defines slot component
durations (eg `ATTESTATION_DUE_BPS`) with config variables where the
unit is basis points (a common way to describe percentages). This will
make it easier to test different slot times and fine-tune slot component
durations. To test a different slot time, change `SLOT_DURATION_MS` and
the component times will automatically adjust since they are percentages
of `SLOT_DURATION_MS`.

Author: jtraglia

configs/mainnet.yaml

@@ -67,8 +67,10 @@ EIP7805_FORK_EPOCH: 18446744073709551615
 
 # Time parameters
 # ---------------------------------------------------------------
-# 12 seconds
+# 12 seconds (*deprecated*)
 SECONDS_PER_SLOT: 12
+# 12000 milliseconds, 12 seconds
+SLOT_DURATION_MS: 12000
 # 14 (estimate from Eth1 mainnet)
 SECONDS_PER_ETH1_BLOCK: 14
 # 2**8 (= 256) epochs, ~27 hours
@@ -77,6 +79,38 @@ MIN_VALIDATOR_WITHDRAWABILITY_DELAY: 256
 SHARD_COMMITTEE_PERIOD: 256
 # 2**11 (= 2,048) Eth1 blocks, ~8 hours
 ETH1_FOLLOW_DISTANCE: 2048
+# 1667 basis points, ~17% of SLOT_DURATION_MS
+PROPOSER_REORG_CUTOFF_BPS: 1667
+# 3333 basis points, ~33% of SLOT_DURATION_MS
+ATTESTATION_DUE_BPS: 3333
+# 6667 basis points, ~67% of SLOT_DURATION_MS
+AGGREGRATE_DUE_BPS: 6667
+
+# Altair
+# 3333 basis points, ~33% of SLOT_DURATION_MS
+SYNC_MESSAGE_DUE_BPS: 3333
+# 6667 basis points, ~67% of SLOT_DURATION_MS
+CONTRIBUTION_DUE_BPS: 6667
+
+# EIP-7732
+# 2500 basis points, 25% of SLOT_DURATION_MS
+ATTESTATION_DUE_BPS_EIP7732: 2500
+# 5000 basis points, 50% of SLOT_DURATION_MS
+AGGREGRATE_DUE_BPS_EIP7732: 5000
+# 2500 basis points, 25% of SLOT_DURATION_MS
+SYNC_MESSAGE_DUE_BPS_EIP7732: 2500
+# 5000 basis points, 50% of SLOT_DURATION_MS
+CONTRIBUTION_DUE_BPS_EIP7732: 5000
+# 7500 basis points, 75% of SLOT_DURATION_MS
+PAYLOAD_ATTESTATION_DUE_BPS: 7500
+
+# EIP-7805
+# 7500 basis points, 75% of SLOT_DURATION_MS
+VIEW_FREEZE_CUTOFF_BPS: 7500
+# 6667 basis points, ~67% of SLOT_DURATION_MS
+INCLUSION_LIST_SUBMISSION_DUE_BPS: 6667
+# 9167 basis points, ~92% of SLOT_DURATION_MS
+PROPOSER_INCLUSION_LIST_CUTOFF_BPS: 9167
 
 # Validator cycle
 # ---------------------------------------------------------------
@@ -182,10 +216,6 @@ MAX_REQUEST_PAYLOADS: 128
 PROPOSER_SCORE_BOOST_EIP7732: 20
 
 # EIP7805
-ATTESTATION_DEADLINE: 4
-INCLUSION_LIST_SUBMISSION_DEADLINE: 8
-VIEW_FREEZE_DEADLINE: 9
-PROPOSER_INCLUSION_LIST_CUTOFF: 11
 # 2**4 (= 16)
 MAX_REQUEST_INCLUSION_LIST: 16
 # 2**13 (= 8192)

configs/minimal.yaml

@@ -63,8 +63,10 @@ EIP7805_FORK_EPOCH: 18446744073709551615
 
 # Time parameters
 # ---------------------------------------------------------------
-# [customized] 6 seconds
+# [customized] 6 seconds (*deprecated*)
 SECONDS_PER_SLOT: 6
+# [customized] 6000 milliseconds, 6 seconds
+SLOT_DURATION_MS: 6000
 # 14 (estimate from Eth1 mainnet)
 SECONDS_PER_ETH1_BLOCK: 14
 # 2**8 (= 256) epochs, ~27 hours
@@ -73,6 +75,38 @@ MIN_VALIDATOR_WITHDRAWABILITY_DELAY: 256
 SHARD_COMMITTEE_PERIOD: 64
 # [customized] 2**4 (= 16) Eth1 blocks, ~4 minutes
 ETH1_FOLLOW_DISTANCE: 16
+# 1667 basis points, ~17% of SLOT_DURATION_MS
+PROPOSER_REORG_CUTOFF_BPS: 1667
+# 3333 basis points, ~33% of SLOT_DURATION_MS
+ATTESTATION_DUE_BPS: 3333
+# 6667 basis points, ~67% of SLOT_DURATION_MS
+AGGREGRATE_DUE_BPS: 6667
+
+# Altair
+# 3333 basis points, ~33% of SLOT_DURATION_MS
+SYNC_MESSAGE_DUE_BPS: 3333
+# 6667 basis points, ~67% of SLOT_DURATION_MS
+CONTRIBUTION_DUE_BPS: 6667
+
+# EIP-7732
+# 2500 basis points, 25% of SLOT_DURATION_MS
+ATTESTATION_DUE_BPS_EIP7732: 2500
+# 5000 basis points, 50% of SLOT_DURATION_MS
+AGGREGRATE_DUE_BPS_EIP7732: 5000
+# 2500 basis points, 25% of SLOT_DURATION_MS
+SYNC_MESSAGE_DUE_BPS_EIP7732: 2500
+# 5000 basis points, 50% of SLOT_DURATION_MS
+CONTRIBUTION_DUE_BPS_EIP7732: 5000
+# 7500 basis points, 75% of SLOT_DURATION_MS
+PAYLOAD_ATTESTATION_DUE_BPS: 7500
+
+# EIP-7805
+# 7500 basis points, 75% of SLOT_DURATION_MS
+VIEW_FREEZE_CUTOFF_BPS: 7500
+# 6667 basis points, ~67% of SLOT_DURATION_MS
+INCLUSION_LIST_SUBMISSION_DUE_BPS: 6667
+# 9167 basis points, ~92% of SLOT_DURATION_MS
+PROPOSER_INCLUSION_LIST_CUTOFF_BPS: 9167
 
 # Validator cycle
 # ---------------------------------------------------------------
@@ -179,10 +213,6 @@ MAX_REQUEST_PAYLOADS: 128
 PROPOSER_SCORE_BOOST_EIP7732: 20
 
 # EIP7805
-ATTESTATION_DEADLINE: 2
-INCLUSION_LIST_SUBMISSION_DEADLINE: 2
-VIEW_FREEZE_DEADLINE: 3
-PROPOSER_INCLUSION_LIST_CUTOFF: 5
 # 2**4 (= 16)
 MAX_REQUEST_INCLUSION_LIST: 16
 # 2**13 (= 8192)

specs/_features/eip7732/fork-choice.md

@@ -50,7 +50,6 @@ This is the modification of the fork-choice accompanying the EIP-7732 upgrade.
 | Name                       | Value                   |
 | -------------------------- | ----------------------- |
 | `PAYLOAD_TIMELY_THRESHOLD` | `PTC_SIZE // 2` (= 256) |
-| `INTERVALS_PER_SLOT`       | `4`                     |
 | `PAYLOAD_STATUS_PENDING`   | `PayloadStatus(0)`      |
 | `PAYLOAD_STATUS_EMPTY`     | `PayloadStatus(1)`      |
 | `PAYLOAD_STATUS_FULL`      | `PayloadStatus(2)`      |
@@ -485,8 +484,11 @@ def on_block(store: Store, signed_block: SignedBeaconBlock) -> None:
     # Notify the store about the payload_attestations in the block
     notify_ptc_messages(store, state, block.body.payload_attestations)
     # Add proposer score boost if the block is timely
-    time_into_slot = (store.time - store.genesis_time) % SECONDS_PER_SLOT
-    is_before_attesting_interval = time_into_slot < SECONDS_PER_SLOT // INTERVALS_PER_SLOT
+    seconds_since_genesis = store.time - store.genesis_time
+    time_into_slot_ms = seconds_to_milliseconds(seconds_since_genesis) % SLOT_DURATION_MS
+    # [Modified in EIP7732]
+    attestation_threshold_ms = get_slot_component_duration_ms(ATTESTATION_DUE_BPS_EIP7732)
+    is_before_attesting_interval = time_into_slot_ms < attestation_threshold_ms
     is_timely = get_current_slot(store) == block.slot and is_before_attesting_interval
     store.block_timeliness[hash_tree_root(block)] = is_timely
 

specs/_features/eip7732/validator.md

@@ -5,6 +5,8 @@
 <!-- mdformat-toc start --slug=github --no-anchors --maxlevel=6 --minlevel=2 -->
 
 - [Introduction](#introduction)
+- [Configuration](#configuration)
+  - [Time parameters](#time-parameters)
 - [Validator assignment](#validator-assignment)
   - [Lookahead](#lookahead)
 - [Beacon chain responsibilities](#beacon-chain-responsibilities)
@@ -26,6 +28,18 @@
 This document represents the changes and additions to the Honest validator guide
 included in the EIP-7732 fork.
 
+## Configuration
+
+### Time parameters
+
+| Name                           | Value          |     Unit     |         Duration          |
+| ------------------------------ | -------------- | :----------: | :-----------------------: |
+| `ATTESTATION_DUE_BPS_EIP7732`  | `uint64(2500)` | basis points | 25% of `SLOT_DURATION_MS` |
+| `AGGREGRATE_DUE_BPS_EIP7732`   | `uint64(5000)` | basis points | 50% of `SLOT_DURATION_MS` |
+| `SYNC_MESSAGE_DUE_BPS_EIP7732` | `uint64(2500)` | basis points | 25% of `SLOT_DURATION_MS` |
+| `CONTRIBUTION_DUE_BPS_EIP7732` | `uint64(5000)` | basis points | 50% of `SLOT_DURATION_MS` |
+| `PAYLOAD_ATTESTATION_DUE_BPS`  | `uint64(7500)` | basis points | 75% of `SLOT_DURATION_MS` |
+
 ## Validator assignment
 
 A validator may be a member of the new Payload Timeliness Committee (PTC) for a
@@ -69,16 +83,17 @@ All validator responsibilities remain unchanged other than the following:
   becomes a builder's duty.
 - Some validators are selected per slot to become PTC members, these validators
   must broadcast `PayloadAttestationMessage` objects during the assigned slot
-  before the deadline of `3 * SECONDS_PER_SLOT // INTERVALS_PER_SLOT` seconds
+  before the deadline of
+  `get_slot_component_duration_ms(PAYLOAD_ATTESTATION_DUE_BPS)` milliseconds
   into the slot.
 
 ### Attestation
 
-The attestation deadline is implicitly changed by the change in
-`INTERVALS_PER_SLOT`. Moreover, the `attestation.data.index` field is now used
-to signal the payload status of the block being attested to
-(`attestation.data.beacon_block_root`). With the alias
-`data = attestation.data`, the validator should set this field as follows:
+The attestation deadline is changed with `ATTESTATION_DUE_BPS_EIP7732`.
+Moreover, the `attestation.data.index` field is now used to signal the payload
+status of the block being attested to (`attestation.data.beacon_block_root`).
+With the alias `data = attestation.data`, the validator should set this field as
+follows:
 
 - If `block.slot == current_slot` (i.e., `data.slot`), then always set
   `data.index = 0`.
@@ -92,7 +107,7 @@ to signal the payload status of the block being attested to
 ### Sync Committee participations
 
 Sync committee duties are not changed for validators, however the submission
-deadline is implicitly changed by the change in `INTERVALS_PER_SLOT`.
+deadline is changed with `SYNC_MESSAGE_DUE_BPS_EIP7732`.
 
 ### Block proposal
 
@@ -152,16 +167,17 @@ prepared to submit their PTC attestations during the next epoch.
 
 A validator should create and broadcast the `payload_attestation_message` to the
 global execution attestation subnet not after
-`SECONDS_PER_SLOT * 3 / INTERVALS_PER_SLOT` seconds since the start of `slot`
+`get_slot_component_duration_ms(PAYLOAD_ATTESTATION_DUE_BPS)` milliseconds since
+the start of `slot`.
 
 #### Constructing a payload attestation
 
 If a validator is in the payload attestation committee for the current slot (as
 obtained from `get_ptc_assignment` above) then the validator should prepare a
 `PayloadAttestationMessage` for the current slot, according to the logic in
 `get_payload_attestation_message` below and broadcast it not after
-`SECONDS_PER_SLOT * 3 / INTERVALS_PER_SLOT` seconds since the start of the slot,
-to the global `payload_attestation_message` pubsub topic.
+`get_slot_component_duration_ms(PAYLOAD_ATTESTATION_DUE_BPS)` milliseconds since
+the start of the slot, to the global `payload_attestation_message` pubsub topic.
 
 The validator creates `payload_attestation_message` as follows:
 

specs/_features/eip7805/fork-choice.md

@@ -30,9 +30,9 @@ This is the modification of the fork choice accompanying the EIP-7805 upgrade.
 
 ### Time parameters
 
-| Name                   | Value                           |  Unit   | Duration  |
-| ---------------------- | ------------------------------- | :-----: | :-------: |
-| `VIEW_FREEZE_DEADLINE` | `SECONDS_PER_SLOT * 2 // 3 + 1` | seconds | 9 seconds |
+| Name                     | Value          |     Unit     |         Duration          |
+| ------------------------ | -------------- | :----------: | :-----------------------: |
+| `VIEW_FREEZE_CUTOFF_BPS` | `uint64(7500)` | basis points | 75% of `SLOT_DURATION_MS` |
 
 ## Protocols
 
@@ -270,12 +270,12 @@ def on_inclusion_list(store: Store, signed_inclusion_list: SignedInclusionList)
 
     inclusion_list_store = get_inclusion_list_store()
 
-    time_into_slot = (store.time - store.genesis_time) % SECONDS_PER_SLOT
-    is_before_view_freeze_deadline = (
-        get_current_slot(store) == inclusion_list.slot and time_into_slot < VIEW_FREEZE_DEADLINE
-    )
+    seconds_since_genesis = store.time - store.genesis_time
+    time_into_slot_ms = seconds_to_milliseconds(seconds_since_genesis) % SLOT_DURATION_MS
+    view_freeze_cutoff_ms = get_slot_component_duration_ms(VIEW_FREEZE_CUTOFF_BPS)
+    is_before_view_freeze_cutoff = time_into_slot_ms < view_freeze_cutoff_ms
 
-    process_inclusion_list(inclusion_list_store, inclusion_list, is_before_view_freeze_deadline)
+    process_inclusion_list(inclusion_list_store, inclusion_list, is_before_view_freeze_cutoff)
 ```
 
 ### Modified `on_block`
@@ -324,8 +324,10 @@ def on_block(store: Store, signed_block: SignedBeaconBlock) -> None:
     store.block_states[block_root] = state
 
     # Add block timeliness to the store
-    time_into_slot = (store.time - store.genesis_time) % SECONDS_PER_SLOT
-    is_before_attesting_interval = time_into_slot < SECONDS_PER_SLOT // INTERVALS_PER_SLOT
+    seconds_since_genesis = store.time - store.genesis_time
+    time_into_slot_ms = seconds_to_milliseconds(seconds_since_genesis) % SLOT_DURATION_MS
+    attestation_threshold_ms = get_slot_component_duration_ms(ATTESTATION_DUE_BPS)
+    is_before_attesting_interval = time_into_slot_ms < attestation_threshold_ms
     is_timely = get_current_slot(store) == block.slot and is_before_attesting_interval
     store.block_timeliness[hash_tree_root(block)] = is_timely
 

specs/_features/eip7805/p2p-interface.md

@@ -21,10 +21,6 @@ EIP-7805.
 
 ### Configuration
 
-| Name                   | Value                   |  Unit   | Duration  |
-| ---------------------- | ----------------------- | :-----: | :-------: |
-| `ATTESTATION_DEADLINE` | `SECONDS_PER_SLOT // 3` | seconds | 4 seconds |
-
 | Name                           | Value            | Description                                                |
 | ------------------------------ | ---------------- | ---------------------------------------------------------- |
 | `MAX_REQUEST_INCLUSION_LIST`   | `2**4` (= 16)    | Maximum number of inclusion list in a single request       |
@@ -56,7 +52,8 @@ the network, assuming the alias `message = signed_inclusion_list.message`:
 - _[REJECT]_ The slot `message.slot` is equal to the previous or current slot.
 - _[IGNORE]_ The slot `message.slot` is equal to the current slot, or it is
   equal to the previous slot and the current time is less than
-  `ATTESTATION_DEADLINE` seconds into the slot.
+  `get_slot_component_duration_ms(ATTESTATION_DUE_BPS)` milliseconds into the
+  slot.
 - _[IGNORE]_ The `inclusion_list_committee` for slot `message.slot` on the
   current branch corresponds to `message.inclusion_list_committee_root`, as
   determined by

specs/_features/eip7805/validator.md

@@ -50,10 +50,10 @@ continuing and use them as a reference throughout.
 
 ### Time parameters
 
-| Name                                 | Value                       |  Unit   |  Duration  |
-| ------------------------------------ | --------------------------- | :-----: | :--------: |
-| `INCLUSION_LIST_SUBMISSION_DEADLINE` | `SECONDS_PER_SLOT * 2 // 3` | seconds | 8 seconds  |
-| `PROPOSER_INCLUSION_LIST_CUTOFF`     | `SECONDS_PER_SLOT - 1`      | seconds | 11 seconds |
+| Name                                 | Value          |     Unit     |          Duration          |
+| ------------------------------------ | -------------- | :----------: | :------------------------: |
+| `INCLUSION_LIST_SUBMISSION_DUE_BPS`  | `uint64(6667)` | basis points | ~67% of `SLOT_DURATION_MS` |
+| `PROPOSER_INCLUSION_LIST_CUTOFF_BPS` | `uint64(9167)` | basis points | ~92% of `SLOT_DURATION_MS` |
 
 ## Helpers
 
@@ -150,7 +150,8 @@ processed through any empty slots up to the assigned slot using
 
 *Note*: A proposer should produce an execution payload that satisfies the
 inclusion list constraints with respect to the inclusion lists gathered up to
-`PROPOSER_INCLUSION_LIST_CUTOFF` into the slot.
+`get_slot_component_duration_ms(PROPOSER_INCLUSION_LIST_CUTOFF_BPS)`
+milliseconds into the slot.
 
 ```python
 def prepare_execution_payload(
@@ -198,12 +199,14 @@ of any `slot` for which
 
 If a validator is in the current inclusion list committee, the validator should
 create and broadcast the `signed_inclusion_list` to the global `inclusion_list`
-subnet by `INCLUSION_LIST_SUBMISSION_DEADLINE` seconds into the slot after
-processing the block for the current slot and confirming it as the head. If no
-block is received by `INCLUSION_LIST_SUBMISSION_DEADLINE - 1` seconds into the
-slot, the validator should run `get_head` to determine the local head and
-construct and broadcast the inclusion list based on this local head by
-`INCLUSION_LIST_SUBMISSION_DEADLINE` seconds into the slot.
+subnet by `get_slot_component_duration_ms(INCLUSION_LIST_SUBMISSION_DUE_BPS)`
+milliseconds into the slot after processing the block for the current slot and
+confirming it as the head. If no block is received by
+`get_slot_component_duration_ms(INCLUSION_LIST_SUBMISSION_DUE_BPS) - 1000`
+milliseconds into the slot, the validator should run `get_head` to determine the
+local head and construct and broadcast the inclusion list based on this local
+head by `get_slot_component_duration_ms(INCLUSION_LIST_SUBMISSION_DUE_BPS)`
+milliseconds into the slot.
 
 #### Constructing the `SignedInclusionList`
 

specs/altair/light-client/p2p-interface.md

@@ -64,9 +64,9 @@ the network.
   `finality_update` for that slot did not indicate supermajority
 - _[IGNORE]_ The `finality_update` is received after the block at
   `signature_slot` was given enough time to propagate through the network --
-  i.e. validate that one-third of `finality_update.signature_slot` has
-  transpired (`SECONDS_PER_SLOT / INTERVALS_PER_SLOT` seconds after the start of
-  the slot, with a `MAXIMUM_GOSSIP_CLOCK_DISPARITY` allowance)
+  i.e. validatate that `get_slot_component_duration_ms(SYNC_MESSAGE_DUE_BPS)`
+  milliseconds (with a `MAXIMUM_GOSSIP_CLOCK_DISPARITY` allowance) has
+  transpired since the start of `signature_slot`.
 
 For full nodes, the following validations MUST additionally pass before
 forwarding the `finality_update` on the network.
@@ -111,9 +111,9 @@ the network.
   previously forwarded `optimistic_update`s
 - _[IGNORE]_ The `optimistic_update` is received after the block at
   `signature_slot` was given enough time to propagate through the network --
-  i.e. validate that one-third of `optimistic_update.signature_slot` has
-  transpired (`SECONDS_PER_SLOT / INTERVALS_PER_SLOT` seconds after the start of
-  the slot, with a `MAXIMUM_GOSSIP_CLOCK_DISPARITY` allowance)
+  i.e. validatate that `get_slot_component_duration_ms(SYNC_MESSAGE_DUE_BPS)`
+  milliseconds (with a `MAXIMUM_GOSSIP_CLOCK_DISPARITY` allowance) has
+  transpired since the start of `optimistic_update.signature_slot`.
 
 For full nodes, the following validations MUST additionally pass before
 forwarding the `optimistic_update` on the network.
@@ -371,9 +371,9 @@ follows:
   SHOULD be broadcasted to the pubsub topic `light_client_optimistic_update` if
   no matching message has not yet been forwarded as part of gossip validation.
 
-These messages SHOULD be broadcasted after one-third of `slot` has transpired
-(`SECONDS_PER_SLOT / INTERVALS_PER_SLOT` seconds after the start of the slot).
-To ensure that the corresponding block was given enough time to propagate
-through the network, they SHOULD NOT be sent earlier. Note that this is
-different from how other messages are handled, e.g., attestations, which may be
-sent early.
+These messages SHOULD be broadcasted
+`get_slot_component_duration_ms(SYNC_MESSAGE_DUE_BPS)` milliseconds after the
+start of the slot. To ensure that the corresponding block was given enough time
+to propagate through the network, they SHOULD NOT be sent earlier. Note that
+this is different from how other messages are handled, e.g., attestations, which
+may be sent early.