diff options
Diffstat (limited to 'synapse/storage/databases/main/lock.py')
| -rw-r--r-- | synapse/storage/databases/main/lock.py | 121 |
1 files changed, 39 insertions, 82 deletions
diff --git a/synapse/storage/databases/main/lock.py b/synapse/storage/databases/main/lock.py index 2d7633fbd5..7270ef09da 100644 --- a/synapse/storage/databases/main/lock.py +++ b/synapse/storage/databases/main/lock.py @@ -129,91 +129,48 @@ class LockStore(SQLBaseStore): now = self._clock.time_msec() token = random_string(6) - if self.db_pool.engine.can_native_upsert: - - def _try_acquire_lock_txn(txn: LoggingTransaction) -> bool: - # We take out the lock if either a) there is no row for the lock - # 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 (?, ?, ?, ?, ?) - ON CONFLICT (lock_name, lock_key) - DO UPDATE - SET - token = EXCLUDED.token, - instance_name = EXCLUDED.instance_name, - last_renewed_ts = EXCLUDED.last_renewed_ts - WHERE - worker_locks.last_renewed_ts < ? - OR worker_locks.instance_name = EXCLUDED.instance_name - """ - txn.execute( - sql, - ( - lock_name, - lock_key, - self._instance_name, - token, - now, - now - _LOCK_TIMEOUT_MS, - ), - ) - - # We only acquired the lock if we inserted or updated the table. - return bool(txn.rowcount) - - did_lock = await self.db_pool.runInteraction( - "try_acquire_lock", - _try_acquire_lock_txn, - # We can autocommit here as we're executing a single query, this - # will avoid serialization errors. - db_autocommit=True, + def _try_acquire_lock_txn(txn: LoggingTransaction) -> bool: + # We take out the lock if either a) there is no row for the lock + # 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 (?, ?, ?, ?, ?) + ON CONFLICT (lock_name, lock_key) + DO UPDATE + SET + token = EXCLUDED.token, + instance_name = EXCLUDED.instance_name, + last_renewed_ts = EXCLUDED.last_renewed_ts + WHERE + worker_locks.last_renewed_ts < ? + OR worker_locks.instance_name = EXCLUDED.instance_name + """ + txn.execute( + sql, + ( + lock_name, + lock_key, + self._instance_name, + token, + now, + now - _LOCK_TIMEOUT_MS, + ), ) - if not did_lock: - return None - - else: - # If we're on an old SQLite we emulate the above logic by first - # clearing out any existing stale locks and then upserting. - - def _try_acquire_lock_emulated_txn(txn: LoggingTransaction) -> bool: - sql = """ - DELETE FROM worker_locks - WHERE - lock_name = ? - AND lock_key = ? - AND (last_renewed_ts < ? OR instance_name = ?) - """ - txn.execute( - sql, - (lock_name, lock_key, now - _LOCK_TIMEOUT_MS, self._instance_name), - ) - - inserted = self.db_pool.simple_upsert_txn_emulated( - txn, - table="worker_locks", - keyvalues={ - "lock_name": lock_name, - "lock_key": lock_key, - }, - values={}, - insertion_values={ - "token": token, - "last_renewed_ts": self._clock.time_msec(), - "instance_name": self._instance_name, - }, - ) - - return inserted - did_lock = await self.db_pool.runInteraction( - "try_acquire_lock_emulated", _try_acquire_lock_emulated_txn - ) + # We only acquired the lock if we inserted or updated the table. + return bool(txn.rowcount) - if not did_lock: - return None + did_lock = await self.db_pool.runInteraction( + "try_acquire_lock", + _try_acquire_lock_txn, + # We can autocommit here as we're executing a single query, this + # will avoid serialization errors. + db_autocommit=True, + ) + if not did_lock: + return None lock = Lock( self._reactor, |