AE_BARRIER was implemented like:
- Fire the readable event.
- Do not fire the writabel event if the readable fired.
However this may lead to the writable event to never be called if the
readable event is always fired. There is an alterantive, we can just
invert the sequence of the calls in case AE_BARRIER is set. This commit
does that.
AE_BARRIER was implemented like:
- Fire the readable event.
- Do not fire the writabel event if the readable fired.
However this may lead to the writable event to never be called if the
readable event is always fired. There is an alterantive, we can just
invert the sequence of the calls in case AE_BARRIER is set. This commit
does that.
In case the write handler is already installed, it could happen that we
serve the reply of a query in the same event loop cycle we received it,
preventing beforeSleep() from guaranteeing that we do the AOF fsync
before sending the reply to the client.
The AE_BARRIER mechanism, introduced in a previous commit, prevents this
problem. This commit makes actual use of this new feature to fix the
bug.
In case the write handler is already installed, it could happen that we
serve the reply of a query in the same event loop cycle we received it,
preventing beforeSleep() from guaranteeing that we do the AOF fsync
before sending the reply to the client.
The AE_BARRIER mechanism, introduced in a previous commit, prevents this
problem. This commit makes actual use of this new feature to fix the
bug.
Add AE_BARRIER to the writable event loop so that slaves requesting
votes can't be served before we re-enter the event loop in the next
iteration, so clusterBeforeSleep() will fsync to disk in time.
Also add the call to explicitly fsync, given that we modified the last
vote epoch variable.
Add AE_BARRIER to the writable event loop so that slaves requesting
votes can't be served before we re-enter the event loop in the next
iteration, so clusterBeforeSleep() will fsync to disk in time.
Also add the call to explicitly fsync, given that we modified the last
vote epoch variable.
