poorbarcode opened a new pull request, #24607:
URL: https://github.com/apache/pulsar/pull/24607
### Motivation
If more the one task named `expireMessage` were executed at the same time,
the mechanism `expirationCheckInProgress` prevents them from executing
concurrently, but it is not well enough.
| `task: expire msg 1` | `task: expire msg 2` |
| --- | --- |
| `expirationCheckInProgress` -> `true`<sup>[1]</sup> |
| find target position<sup>[2]</sup> |
| start to reset cursor<sup>[3]</sup> |
| `expirationCheckInProgress` -> `false`sup>[3]</sup> |
| | `expirationCheckInProgress` -> `true`<sup>[1]</sup> |
| | find target position<sup>[2]</sup> |
| | start to reset cursor<sup>[3]</sup> |
| | get an error: `cursor reset in progress - ignoring mark delete on
position [{}] for cursor [{}]` |
| end resetting cursor |
- **[1]**: `PersistentSubscription.expireMessages`
- **[2]**: `PersistentMessageExpiryMonitor.expireMessages`
- **[3]**: `PersistentMessageExpiryMonitor.findEntryComplete`
The above concurrency wasted a finding target position, which is a heavy
operation.
### Modifications
Release the lock `expirationCheckInProgress` after resetting cursor
successfully.
### Documentation
<!-- DO NOT REMOVE THIS SECTION. CHECK THE PROPER BOX ONLY. -->
- [ ] `doc` <!-- Your PR contains doc changes. -->
- [ ] `doc-required` <!-- Your PR changes impact docs and you will update
later -->
- [x] `doc-not-needed` <!-- Your PR changes do not impact docs -->
- [ ] `doc-complete` <!-- Docs have been already added -->
### Matching PR in forked repository
PR in forked repository: x
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