.

zloadrace.py

@@ -20,6 +20,20 @@ and later again by https://github.com/zopefoundation/ZEO/commit/94f275c3 .
 NEO
 ---
 
+There is no load vs invalidation race on NEO but the protection is implicit:
+
+- client app maintains .last_tid which is updated by poller thread upon
+  receiving invalidations.
+- when load() is called without specifing @head (the case we are considering),
+  it uses .last_tid for @at with which to ask storage node.
+- even if client.load() observes .last_tid which was updated for simultaneously
+  committed transaction and not yet invalidated cache the following happens:
+
+  * client sends AskObject packet to a storage node.
+  * ask _locks_ corresponding connection to the storage. XXX _not_ to master from which we should have received invalidation message !
+
+- client.app.load
+
 
 XXX load vs invalidation race is there on ZODB4 and ZODB3, but on ZODB5 there is
 another open vs invalidation race.