Fix a few thread sanitizer failures #5643
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tgoyne
commented
Jul 2, 2022
| @@ -2577,7 +2575,6 @@ DisableReplication::DisableReplication(Transaction& t) | |||
| , m_version(t.get_version()) | |||
| { | |||
| m_owner->set_replication(nullptr); | |||
| t.get_version(); | |||
The emulated implementation of InterprocessCondVar requires that the associated mutex be held when `notify_all()` is called because it performs non-atomic reads and writes on the shared part, which would be a data race if done without a mutex covering the acceses. This is already noted as a precondition of the function, which DB::do_end_write() violated.
Calling `DB::set_replication()` inside a write transaction is _almost_ safe to do, but it turns out that there's a few scenarios where the sync client will call `DB::get_replication()` outside of a write. Scoping the replication setting to just the specific Table fixes this (as live Table accessors actually are thread-confined) and also simplifies the logic a bit.
ironage
approved these changes
Jul 7, 2022
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The emulated implementation of InterprocessCondVar requires that the associated mutex be held when
notify_all()is called because it performs non-atomic reads and writes on the shared part, which would be a data race if done without a mutex covering the access. This is already noted as a precondition of the function, which DB::do_end_write() violated.Calling
DB::set_replication()inside a write transaction is almost safe to do, but it turns out that there's a few scenarios where the sync client will callDB::get_replication()outside of a write. Scoping the replication setting to just the specific Table fixes this (as live Table accessors actually are thread-confined) and also simplifies the logic a bit.