Done in preparation to make ShardArgs a smart iterable type,
but currently it's just a wrapper aroung ArgSlice.
Also refactored common.{h,cc} into tx_base.{h,cc}
In addition, fixed a bug in key tracking, where we wrongly created weak_ref
in a shard thread instead of doing this in the coordinator thread.
Finally, identified another bug (not fixed yet) where we track all the arguments
instead of tracking keys only.
Besides this, no functional changes around the moved code.
Signed-off-by: Roman Gershman <roman@dragonflydb.io>
1. Replaces run_barrier as a synchronization point with is_armed + an embedded blocking counter for awaiting running jobs
2. Replaces IsArmedInShard + GetLocalMask + is_armed.exchange chain with a single DisarmInShard() / DisarmInShardWhen
Signed-off-by: Vladislav Oleshko <vlad@dragonflydb.io>
* fix: Remove a stale reference to blocking watch queue
1. Remove the duplicated FinalizeWatched function
2. Identify the case where we delete the watched queue while we may still have awakedened_keys pointing to it.
3. Add a test reproducing the issue of having in awakened_keys an untangled key.
Properly fixes#2514
Signed-off-by: Roman Gershman <roman@dragonflydb.io>
---------
Signed-off-by: Roman Gershman <roman@dragonflydb.io>
Output more info about the state of things.
Skip the non existent key and continue the execution.
Fixes#2514
Signed-off-by: Roman Gershman <roman@dragonflydb.io>
1. Added a test that was breaking earlier.
2. Made sure that multiple waked brpop transaction would not
snatch items from one another.
3. Fixed watched-queues clean-up logic inside blocking_controller that caused deadlocks.
Signed-off-by: Roman Gershman <roman@dragonflydb.io>
1. pytest extensions and fixes - allows running them
with the existing local server by providing its port (--existing <port>).
2. Extend "DEBUG WATCHED" command to provide more information about watched state.
3. Improve debug/vlog printings around the code.
This noisy PR is a preparation before BRPOP fix that will follow later.
Signed-off-by: Roman Gershman <roman@dragonflydb.io>
fix(server): Fix a bug when an expired transaction stays in watched queue.
Now we remove the transaction from the watched queues in a consistent manner based on the
keys it was assigned to watch.
Signed-off-by: Roman Gershman <roman@dragonflydb.io>
Signed-off-by: Roman Gershman <roman@dragonflydb.io>
Partially implements #6.
Before, each shard lazily updated its clock used for the expiry evaluation.
Now, the clock value is set during the transaction scheduling phase and is assigned
to each transaction. From now on DbSlice methods use this value when checking whether
the entry is expired via passed DbContext argument.
Also, implemented transactionally consistent TIME command and
verify that time is the same during the transaction. See
https://ably.com/blog/redis-keys-do-not-expire-atomically for motivation.
Still have not implemented any lamport style updates for background processes
(not sure if it's the right way to proceed).
1. Found dangling transaction pointers that where left in the watch queue. Fix the state machine there.
2. Improved transaction code a bit, merged duplicated code into RunInShard function, got rid of RunNoop.
3. Improved BPopper::Run flow.
4. Added 'DEBUG WATCH' command. Also 'DEBUG OBJECT' now returns shard id and the lock status of the object.
