tree f7d08b6aa343a8b5113f448fe328178f3f03bbdd
parent bb5c1fcb59e5bb8cf1ceee9fe78247677b35959e
author Yunze Xu <xyzinfernity@163.com> 1683365140 +0800
committer Yunze Xu <xyzinfernity@163.com> 1683365237 +0800

Fix deadlock for negative acknowledgment (#266)

Fixes https://github.com/apache/pulsar-client-cpp/issues/265

### Modifications

Make `timer_` const and `enabledForTesting_` atomic in
`NegativeAcksTracker` so that the `mutex_` can be used only for the
`nackedMessages_` field. After that, we can unlock `mutex_` in
`handleTimer` to avoid the potential deadlock from user-provided logger
or intercepter.

Add `ConsumerTest.testNegativeAckDeadlock` to verify the fix.

(cherry picked from commit 8a9b2dc7f58b9b4a888be11d8068839abec51310)