CBL App crashes during replication for system test

[hrajput89]

---

• Version: 2.1.0-223
• Client OS: iOS
• Server: CBS 5.5.0-2954

CBL app crashed with "EXC_BAD_ACCESS" while replication the changes after the delete docs on CBL App. The crash happened after the 87th iteration of System Test.

System test is running with initial 1M docs and perform update, delete and addition operation on the cluster with a combination such that after each iteration doc count remains 1M. The crash happened after the delete operation performed on CBL side.

Run System test with below command on feature/diff-cbl20-master

pytest -rsx -s --mode=cc --create-db-per-suite=suite_db --server-version=5.5.0-2954 --sync-gateway-version=2.1.0-121 --xattrs --liteserv-versions=2.1.0-223 --liteserv-hosts=localhost --liteserv-ports=8080 --liteserv-platforms=ios --use-views --timeout=864800 --no-db-delete testsuites/CBLTester/System_test_multiple_device/test_system_testing.py

CBL Python Client logs -
CBL python client log.log

SG logs are around 1GB. I've taken backup for them. Let me know if you need them.

[hrajput89]

stack trace from the lldb shell

https://gist.github.com/hrajput89/0833c57285fbdf20831fd18774dd8f66

[hrajput89]

Replicator code is available here - https://github.com/couchbaselabs/mobile-testkit/blob/feature/diff-cbl20-master/CBLClient/Apps/CBLTestServer-iOS/CBLTestServer-iOS/Server/ReplicatorRequestHandler.swift

[snej]

Crash is in CouchbaseLiteSwift.Replicator.Status.init(withStatus:).

[pasin]

I think the issue is that the CBLReplicator.status is not thread safe. When the swift replicator tired to access it, the status object has been released. We should me the status property thread safe anyway.

[pasin]

Please use RC4 - 2.1-239 to verify the fix. We can reopen the issue if the issue still exists.