diff options
| -rw-r--r-- | synapse/storage/_base.py | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py index 840a4994bb..579ed56377 100644 --- a/synapse/storage/_base.py +++ b/synapse/storage/_base.py @@ -98,6 +98,8 @@ class Cache(object): def update(self, sequence, *args): self.check_thread() if self.sequence == sequence: + # Only update the cache if the caches sequence number matches the + # number that the cache had before the SELECT was started (SYN-369) self.prefill(*args) def prefill(self, *args): # because I can't *keyargs, value @@ -117,6 +119,8 @@ class Cache(object): self.check_thread() if len(keyargs) != self.keylen: raise ValueError("Expected a key to have %d items", self.keylen) + # Increment the sequence number so that any SELECT statements that + # raced with the INSERT don't update the cache (SYN-369) self.sequence += 1 self.cache.pop(keyargs, None) @@ -159,6 +163,9 @@ def cached(max_entries=1000, num_args=1, lru=False): raise ValueError("Stale cache entry") defer.returnValue(cached_result) except KeyError: + # Get the sequence number of the cache before reading from the + # database so that we can tell if the cache is invalidated + # while the SELECT is executing (SYN-369) sequence = cache.sequence ret = yield orig(self, *keyargs) |