lighthouse-pulse/beacon_node/beacon_chain/tests/op_verification.rs
Paul Hauner be4e261e74 Use async code when interacting with EL (#3244)
## Overview

This rather extensive PR achieves two primary goals:

1. Uses the finalized/justified checkpoints of fork choice (FC), rather than that of the head state.
2. Refactors fork choice, block production and block processing to `async` functions.

Additionally, it achieves:

- Concurrent forkchoice updates to the EL and cache pruning after a new head is selected.
- Concurrent "block packing" (attestations, etc) and execution payload retrieval during block production.
- Concurrent per-block-processing and execution payload verification during block processing.
- The `Arc`-ification of `SignedBeaconBlock` during block processing (it's never mutated, so why not?):
    - I had to do this to deal with sending blocks into spawned tasks.
    - Previously we were cloning the beacon block at least 2 times during each block processing, these clones are either removed or turned into cheaper `Arc` clones.
    - We were also `Box`-ing and un-`Box`-ing beacon blocks as they moved throughout the networking crate. This is not a big deal, but it's nice to avoid shifting things between the stack and heap.
    - Avoids cloning *all the blocks* in *every chain segment* during sync.
    - It also has the potential to clean up our code where we need to pass an *owned* block around so we can send it back in the case of an error (I didn't do much of this, my PR is already big enough 😅)
- The `BeaconChain::HeadSafetyStatus` struct was removed. It was an old relic from prior merge specs.

For motivation for this change, see https://github.com/sigp/lighthouse/pull/3244#issuecomment-1160963273

## Changes to `canonical_head` and `fork_choice`

Previously, the `BeaconChain` had two separate fields:

```
canonical_head: RwLock<Snapshot>,
fork_choice: RwLock<BeaconForkChoice>
```

Now, we have grouped these values under a single struct:

```
canonical_head: CanonicalHead {
  cached_head: RwLock<Arc<Snapshot>>,
  fork_choice: RwLock<BeaconForkChoice>
} 
```

Apart from ergonomics, the only *actual* change here is wrapping the canonical head snapshot in an `Arc`. This means that we no longer need to hold the `cached_head` (`canonical_head`, in old terms) lock when we want to pull some values from it. This was done to avoid deadlock risks by preventing functions from acquiring (and holding) the `cached_head` and `fork_choice` locks simultaneously.

## Breaking Changes

### The `state` (root) field in the `finalized_checkpoint` SSE event

Consider the scenario where epoch `n` is just finalized, but `start_slot(n)` is skipped. There are two state roots we might in the `finalized_checkpoint` SSE event:

1. The state root of the finalized block, which is `get_block(finalized_checkpoint.root).state_root`.
4. The state root at slot of `start_slot(n)`, which would be the state from (1), but "skipped forward" through any skip slots.

Previously, Lighthouse would choose (2). However, we can see that when [Teku generates that event](de2b2801c8/data/beaconrestapi/src/main/java/tech/pegasys/teku/beaconrestapi/handlers/v1/events/EventSubscriptionManager.java (L171-L182)) it uses [`getStateRootFromBlockRoot`](de2b2801c8/data/provider/src/main/java/tech/pegasys/teku/api/ChainDataProvider.java (L336-L341)) which uses (1).

I have switched Lighthouse from (2) to (1). I think it's a somewhat arbitrary choice between the two, where (1) is easier to compute and is consistent with Teku.

## Notes for Reviewers

I've renamed `BeaconChain::fork_choice` to `BeaconChain::recompute_head`. Doing this helped ensure I broke all previous uses of fork choice and I also find it more descriptive. It describes an action and can't be confused with trying to get a reference to the `ForkChoice` struct.

I've changed the ordering of SSE events when a block is received. It used to be `[block, finalized, head]` and now it's `[block, head, finalized]`. It was easier this way and I don't think we were making any promises about SSE event ordering so it's not "breaking".

I've made it so fork choice will run when it's first constructed. I did this because I wanted to have a cached version of the last call to `get_head`. Ensuring `get_head` has been run *at least once* means that the cached values doesn't need to wrapped in an `Option`. This was fairly simple, it just involved passing a `slot` to the constructor so it knows *when* it's being run. When loading a fork choice from the store and a slot clock isn't handy I've just used the `slot` that was saved in the `fork_choice_store`. That seems like it would be a faithful representation of the slot when we saved it.

I added the `genesis_time: u64` to the `BeaconChain`. It's small, constant and nice to have around.

Since we're using FC for the fin/just checkpoints, we no longer get the `0x00..00` roots at genesis. You can see I had to remove a work-around in `ef-tests` here: b56be3bc2. I can't find any reason why this would be an issue, if anything I think it'll be better since the genesis-alias has caught us out a few times (0x00..00 isn't actually a real root). Edit: I did find a case where the `network` expected the 0x00..00 alias and patched it here: 3f26ac3e2.

You'll notice a lot of changes in tests. Generally, tests should be functionally equivalent. Here are the things creating the most diff-noise in tests:
- Changing tests to be `tokio::async` tests.
- Adding `.await` to fork choice, block processing and block production functions.
- Refactor of the `canonical_head` "API" provided by the `BeaconChain`. E.g., `chain.canonical_head.cached_head()` instead of `chain.canonical_head.read()`.
- Wrapping `SignedBeaconBlock` in an `Arc`.
- In the `beacon_chain/tests/block_verification`, we can't use the `lazy_static` `CHAIN_SEGMENT` variable anymore since it's generated with an async function. We just generate it in each test, not so efficient but hopefully insignificant.

I had to disable `rayon` concurrent tests in the `fork_choice` tests. This is because the use of `rayon` and `block_on` was causing a panic.

Co-authored-by: Mac L <mjladson@pm.me>
2022-07-03 05:36:50 +00:00

235 lines
7.3 KiB
Rust

//! Tests for gossip verification of voluntary exits, propser slashings and attester slashings.
#![cfg(not(debug_assertions))]
use beacon_chain::observed_operations::ObservationOutcome;
use beacon_chain::test_utils::{
test_spec, AttestationStrategy, BeaconChainHarness, BlockStrategy, DiskHarnessType,
};
use lazy_static::lazy_static;
use sloggers::{null::NullLoggerBuilder, Build};
use std::sync::Arc;
use store::{LevelDB, StoreConfig};
use tempfile::{tempdir, TempDir};
use types::*;
pub const VALIDATOR_COUNT: usize = 24;
lazy_static! {
/// A cached set of keys.
static ref KEYPAIRS: Vec<Keypair> =
types::test_utils::generate_deterministic_keypairs(VALIDATOR_COUNT);
}
type E = MinimalEthSpec;
type TestHarness = BeaconChainHarness<DiskHarnessType<E>>;
type HotColdDB = store::HotColdDB<E, LevelDB<E>, LevelDB<E>>;
fn get_store(db_path: &TempDir) -> Arc<HotColdDB> {
let spec = test_spec::<E>();
let hot_path = db_path.path().join("hot_db");
let cold_path = db_path.path().join("cold_db");
let config = StoreConfig::default();
let log = NullLoggerBuilder.build().expect("logger should build");
HotColdDB::open(&hot_path, &cold_path, |_, _, _| Ok(()), config, spec, log)
.expect("disk store should initialize")
}
fn get_harness(store: Arc<HotColdDB>, validator_count: usize) -> TestHarness {
let harness = BeaconChainHarness::builder(MinimalEthSpec)
.default_spec()
.keypairs(KEYPAIRS[0..validator_count].to_vec())
.fresh_disk_store(store)
.mock_execution_layer()
.build();
harness.advance_slot();
harness
}
#[tokio::test]
async fn voluntary_exit() {
let db_path = tempdir().unwrap();
let store = get_store(&db_path);
let harness = get_harness(store.clone(), VALIDATOR_COUNT);
let spec = &harness.chain.spec.clone();
harness
.extend_chain(
(E::slots_per_epoch() * (spec.shard_committee_period + 1)) as usize,
BlockStrategy::OnCanonicalHead,
AttestationStrategy::AllValidators,
)
.await;
let validator_index1 = VALIDATOR_COUNT - 1;
let validator_index2 = VALIDATOR_COUNT - 2;
let exit1 = harness.make_voluntary_exit(
validator_index1 as u64,
Epoch::new(spec.shard_committee_period),
);
// First verification should show it to be fresh.
assert!(matches!(
harness
.chain
.verify_voluntary_exit_for_gossip(exit1.clone())
.unwrap(),
ObservationOutcome::New(_)
));
// Second should not.
assert!(matches!(
harness
.chain
.verify_voluntary_exit_for_gossip(exit1.clone()),
Ok(ObservationOutcome::AlreadyKnown)
));
// A different exit for the same validator should also be detected as a duplicate.
let exit2 = harness.make_voluntary_exit(
validator_index1 as u64,
Epoch::new(spec.shard_committee_period + 1),
);
assert!(matches!(
harness.chain.verify_voluntary_exit_for_gossip(exit2),
Ok(ObservationOutcome::AlreadyKnown)
));
// Exit for a different validator should be fine.
let exit3 = harness.make_voluntary_exit(
validator_index2 as u64,
Epoch::new(spec.shard_committee_period),
);
assert!(matches!(
harness
.chain
.verify_voluntary_exit_for_gossip(exit3)
.unwrap(),
ObservationOutcome::New(_)
));
}
#[test]
fn proposer_slashing() {
let db_path = tempdir().unwrap();
let store = get_store(&db_path);
let harness = get_harness(store.clone(), VALIDATOR_COUNT);
let validator_index1 = VALIDATOR_COUNT - 1;
let validator_index2 = VALIDATOR_COUNT - 2;
let slashing1 = harness.make_proposer_slashing(validator_index1 as u64);
// First slashing for this proposer should be allowed.
assert!(matches!(
harness
.chain
.verify_proposer_slashing_for_gossip(slashing1.clone())
.unwrap(),
ObservationOutcome::New(_)
));
// Duplicate slashing should be detected.
assert!(matches!(
harness
.chain
.verify_proposer_slashing_for_gossip(slashing1.clone())
.unwrap(),
ObservationOutcome::AlreadyKnown
));
// Different slashing for the same index should be rejected
let slashing2 = ProposerSlashing {
signed_header_1: slashing1.signed_header_2,
signed_header_2: slashing1.signed_header_1,
};
assert!(matches!(
harness
.chain
.verify_proposer_slashing_for_gossip(slashing2)
.unwrap(),
ObservationOutcome::AlreadyKnown
));
// Proposer slashing for a different index should be accepted
let slashing3 = harness.make_proposer_slashing(validator_index2 as u64);
assert!(matches!(
harness
.chain
.verify_proposer_slashing_for_gossip(slashing3)
.unwrap(),
ObservationOutcome::New(_)
));
}
#[test]
fn attester_slashing() {
let db_path = tempdir().unwrap();
let store = get_store(&db_path);
let harness = get_harness(store.clone(), VALIDATOR_COUNT);
// First third of the validators
let first_third = (0..VALIDATOR_COUNT as u64 / 3).collect::<Vec<_>>();
// First half of the validators
let first_half = (0..VALIDATOR_COUNT as u64 / 2).collect::<Vec<_>>();
// Last third of the validators
let last_third = (2 * VALIDATOR_COUNT as u64 / 3..VALIDATOR_COUNT as u64).collect::<Vec<_>>();
// Last half of the validators
let second_half = (VALIDATOR_COUNT as u64 / 2..VALIDATOR_COUNT as u64).collect::<Vec<_>>();
// Slashing for first third of validators should be accepted.
let slashing1 = harness.make_attester_slashing(first_third);
assert!(matches!(
harness
.chain
.verify_attester_slashing_for_gossip(slashing1.clone())
.unwrap(),
ObservationOutcome::New(_)
));
// Overlapping slashing for first half of validators should also be accepted.
let slashing2 = harness.make_attester_slashing(first_half);
assert!(matches!(
harness
.chain
.verify_attester_slashing_for_gossip(slashing2.clone())
.unwrap(),
ObservationOutcome::New(_)
));
// Repeating slashing1 or slashing2 should be rejected
assert!(matches!(
harness
.chain
.verify_attester_slashing_for_gossip(slashing1.clone())
.unwrap(),
ObservationOutcome::AlreadyKnown
));
assert!(matches!(
harness
.chain
.verify_attester_slashing_for_gossip(slashing2.clone())
.unwrap(),
ObservationOutcome::AlreadyKnown
));
// Slashing for last half of validators should be accepted (distinct from all existing)
let slashing3 = harness.make_attester_slashing(second_half);
assert!(matches!(
harness
.chain
.verify_attester_slashing_for_gossip(slashing3)
.unwrap(),
ObservationOutcome::New(_)
));
// Slashing for last third (contained in last half) should be rejected.
let slashing4 = harness.make_attester_slashing(last_third);
assert!(matches!(
harness
.chain
.verify_attester_slashing_for_gossip(slashing4)
.unwrap(),
ObservationOutcome::AlreadyKnown
));
}