## Issue Addressed
Closes#1557
## Proposed Changes
Modify the pruning algorithm so that it mutates the head-tracker _before_ committing the database transaction to disk, and _only if_ all the heads to be removed are still present in the head-tracker (i.e. no concurrent mutations).
In the process of writing and testing this I also had to make a few other changes:
* Use internal mutability for all `BeaconChainHarness` functions (namely the RNG and the graffiti), in order to enable parallel calls (see testing section below).
* Disable logging in harness tests unless the `test_logger` feature is turned on
And chose to make some clean-ups:
* Delete the `NullMigrator`
* Remove type-based configuration for the migrator in favour of runtime config (simpler, less duplicated code)
* Use the non-blocking migrator unless the blocking migrator is required. In the store tests we need the blocking migrator because some tests make asserts about the state of the DB after the migration has run.
* Rename `validators_keypairs` -> `validator_keypairs` in the `BeaconChainHarness`
## Testing
To confirm that the fix worked, I wrote a test using [Hiatus](https://crates.io/crates/hiatus), which can be found here:
https://github.com/michaelsproul/lighthouse/tree/hiatus-issue-1557
That test can't be merged because it inserts random breakpoints everywhere, but if you check out that branch you can run the test with:
```
$ cd beacon_node/beacon_chain
$ cargo test --release --test parallel_tests --features test_logger
```
It should pass, and the log output should show:
```
WARN Pruning deferred because of a concurrent mutation, message: this is expected only very rarely!
```
## Additional Info
This is a backwards-compatible change with no impact on consensus.
The PR:
* Adds the ability to generate a crucial test scenario that isn't possible with `BeaconChainHarness` (i.e. two blocks occupying the same slot; previously forks necessitated skipping slots):
* New testing API: Instead of repeatedly calling add_block(), you generate a sorted `Vec<Slot>` and leave it up to the framework to generate blocks at those slots.
* Jumping backwards to an earlier epoch is a hard error, so that tests necessarily generate blocks in a epoch-by-epoch manner.
* Configures the test logger so that output is printed on the console in case a test fails. The logger also plays well with `--nocapture`, contrary to the existing testing framework
* Rewrites existing fork pruning tests to use the new API
* Adds a tests that triggers finalization at a non epoch boundary slot
* Renamed `BeaconChainYoke` to `BeaconChainTestingRig` because the former has been too confusing
* Fixed multiple tests (e.g. `block_production_different_shuffling_long`, `delete_blocks_and_states`, `shuffling_compatible_simple_fork`) that relied on a weird (and accidental) feature of the old `BeaconChainHarness` that attestations aren't produced for epochs earlier than the current one, thus masking potential bugs in test cases.
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
## Issue Addressed
- Resolves#1451
## Proposed Changes
- Restricts the `contains_block` and `contains_block` so they only indicate a block is present if it descends from the finalized root. This helps to ensure that fork choice never points to a block that has been pruned from the database.
- Resolves#1451
- Before importing a block, double-check that its parent is known and a descendant of the finalized root.
- Split a big, monolithic block verification test into smaller tests.
## Additional Notes
I suspect there would be a craftier way to do the `is_descendant_of_finalized` check, but we're a bit tight on time now and we can optimize later if it starts showing in benches.
## TODO
- [x] Tests
## Issue Addressed
NA
## Proposed Changes
- Refactor the `bls` crate to support multiple BLS "backends" (e.g., milagro, blst, etc).
- Removes some duplicate, unused code in `common/rest_types/src/validator.rs`.
- Removes the old "upgrade legacy keypairs" functionality (these were unencrypted keys that haven't been supported for a few testnets, no one should be using them anymore).
## Additional Info
Most of the files changed are just inconsequential changes to function names.
## TODO
- [x] Optimization levels
- [x] Infinity point: https://github.com/supranational/blst/issues/11
- [x] Ensure milagro *and* blst are tested via CI
- [x] What to do with unsafe code?
- [x] Test infinity point in signature sets
* Layer do_atomically() abstractions properly
* Reduce allocs and DRY get_key_for_col()
* Parameterize HotColdDB with hot and cold item stores
* -impl Store for MemoryStore
* Replace Store uses with HotColdDB
* Ditch Store trait
* cargo fmt
* Style fix
* Readd missing dep that broke the build
* Add PH & MS slot clock changes
* Account for genesis time
* Add progress on duties refactor
* Add simple is_aggregator bool to val subscription
* Start work on attestation_verification.rs
* Add progress on ObservedAttestations
* Progress with ObservedAttestations
* Fix tests
* Add observed attestations to the beacon chain
* Add attestation observation to processing code
* Add progress on attestation verification
* Add first draft of ObservedAttesters
* Add more tests
* Add observed attesters to beacon chain
* Add observers to attestation processing
* Add more attestation verification
* Create ObservedAggregators map
* Remove commented-out code
* Add observed aggregators into chain
* Add progress
* Finish adding features to attestation verification
* Ensure beacon chain compiles
* Link attn verification into chain
* Integrate new attn verification in chain
* Remove old attestation processing code
* Start trying to fix beacon_chain tests
* Split adding into pools into two functions
* Add aggregation to harness
* Get test harness working again
* Adjust the number of aggregators for test harness
* Fix edge-case in harness
* Integrate new attn processing in network
* Fix compile bug in validator_client
* Update validator API endpoints
* Fix aggreagation in test harness
* Fix enum thing
* Fix attestation observation bug:
* Patch failing API tests
* Start adding comments to attestation verification
* Remove unused attestation field
* Unify "is block known" logic
* Update comments
* Supress fork choice errors for network processing
* Add todos
* Tidy
* Add gossip attn tests
* Disallow test harness to produce old attns
* Comment out in-progress tests
* Partially address pruning tests
* Fix failing store test
* Add aggregate tests
* Add comments about which spec conditions we check
* Dont re-aggregate
* Split apart test harness attn production
* Fix compile error in network
* Make progress on commented-out test
* Fix skipping attestation test
* Add fork choice verification tests
* Tidy attn tests, remove dead code
* Remove some accidentally added code
* Fix clippy lint
* Rename test file
* Add block tests, add cheap block proposer check
* Rename block testing file
* Add observed_block_producers
* Tidy
* Switch around block signature verification
* Finish block testing
* Remove gossip from signature tests
* First pass of self review
* Fix deviation in spec
* Update test spec tags
* Start moving over to hashset
* Finish moving observed attesters to hashmap
* Move aggregation pool over to hashmap
* Make fc attn borrow again
* Fix rest_api compile error
* Fix missing comments
* Fix monster test
* Uncomment increasing slots test
* Address remaining comments
* Remove unsafe, use cfg test
* Remove cfg test flag
* Fix dodgy comment
* Ignore aggregates that are already known.
* Unify aggregator modulo logic
* Fix typo in logs
* Refactor validator subscription logic
* Avoid reproducing selection proof
* Skip HTTP call if no subscriptions
* Rename DutyAndState -> DutyAndProof
* Tidy logs
* Print root as dbg
* Fix compile errors in tests
* Fix compile error in test
