diff options
Diffstat (limited to 'synapse/storage/databases/main/lock.py')
| -rw-r--r-- | synapse/storage/databases/main/lock.py | 31 |
1 files changed, 21 insertions, 10 deletions
diff --git a/synapse/storage/databases/main/lock.py b/synapse/storage/databases/main/lock.py index 3d1dff660b..3d0df0cbd4 100644 --- a/synapse/storage/databases/main/lock.py +++ b/synapse/storage/databases/main/lock.py @@ -14,6 +14,7 @@ import logging from types import TracebackType from typing import TYPE_CHECKING, Dict, Optional, Tuple, Type +from weakref import WeakValueDictionary from twisted.internet.interfaces import IReactorCore @@ -61,7 +62,7 @@ class LockStore(SQLBaseStore): # A map from `(lock_name, lock_key)` to the token of any locks that we # think we currently hold. - self._live_tokens: Dict[Tuple[str, str], str] = {} + self._live_tokens: Dict[Tuple[str, str], Lock] = WeakValueDictionary() # When we shut down we want to remove the locks. Technically this can # lead to a race, as we may drop the lock while we are still processing. @@ -80,10 +81,10 @@ class LockStore(SQLBaseStore): # We need to take a copy of the tokens dict as dropping the locks will # cause the dictionary to change. - tokens = dict(self._live_tokens) + locks = dict(self._live_tokens) - for (lock_name, lock_key), token in tokens.items(): - await self._drop_lock(lock_name, lock_key, token) + for lock in locks.values(): + await lock.release() logger.info("Dropped locks due to shutdown") @@ -93,6 +94,11 @@ class LockStore(SQLBaseStore): used (otherwise the lock will leak). """ + # Check if this process has taken out a lock and if it's still valid. + lock = self._live_tokens.get((lock_name, lock_key)) + if lock and await lock.is_still_valid(): + return None + now = self._clock.time_msec() token = random_string(6) @@ -100,7 +106,9 @@ class LockStore(SQLBaseStore): def _try_acquire_lock_txn(txn: LoggingTransaction) -> bool: # We take out the lock if either a) there is no row for the lock - # already or b) the existing row has timed out. + # already, b) the existing row has timed out, or c) the row is + # for this instance (which means the process got killed and + # restarted) sql = """ INSERT INTO worker_locks (lock_name, lock_key, instance_name, token, last_renewed_ts) VALUES (?, ?, ?, ?, ?) @@ -112,6 +120,7 @@ class LockStore(SQLBaseStore): last_renewed_ts = EXCLUDED.last_renewed_ts WHERE worker_locks.last_renewed_ts < ? + OR worker_locks.instance_name = EXCLUDED.instance_name """ txn.execute( sql, @@ -148,11 +157,11 @@ class LockStore(SQLBaseStore): WHERE lock_name = ? AND lock_key = ? - AND last_renewed_ts < ? + AND (last_renewed_ts < ? OR instance_name = ?) """ txn.execute( sql, - (lock_name, lock_key, now - _LOCK_TIMEOUT_MS), + (lock_name, lock_key, now - _LOCK_TIMEOUT_MS, self._instance_name), ) inserted = self.db_pool.simple_upsert_txn_emulated( @@ -179,9 +188,7 @@ class LockStore(SQLBaseStore): if not did_lock: return None - self._live_tokens[(lock_name, lock_key)] = token - - return Lock( + lock = Lock( self._reactor, self._clock, self, @@ -190,6 +197,10 @@ class LockStore(SQLBaseStore): token=token, ) + self._live_tokens[(lock_name, lock_key)] = lock + + return lock + async def _is_lock_still_valid( self, lock_name: str, lock_key: str, token: str ) -> bool: |