Review/dismiss CodeQL double-checked-locking flag on MongoDatabase.baseMongoClient

Summary

The code-quality bot (CodeQL on #816) flags a race condition in double-checked locking for the singleton initialization of baseMongoClient in src/main/java/dbProcs/MongoDatabase.java.

The assignment baseMongoClient = createMongoClient(null); (inside synchronized (lock) at ~line 189) is reported as potentially visible to other threads before subsequent statements complete.

Assessment (please confirm before acting)

This may be low severity / a false positive as currently written:

• baseMongoClient is declared volatile (MongoDatabase.java:54), which gives the double-checked-locking idiom its required safe-publication guarantee under the Java Memory Model (JDK 5+).
• The assignment happens inside synchronized (lock) after createMongoClient(null) returns a fully-constructed client, so no partially-initialized object is published.

The classic DCL bug requires a non-volatile field; with volatile the pattern is correct. The bot's analyzer may not be accounting for the volatile modifier.

Action

• Confirm whether the bot finding is a true positive given the volatile field. If it is a false positive, dismiss the alert (and optionally add a brief code comment explaining the safe-publication guarantee).
• If there's a genuine ordering concern the analysis caught (e.g. other reads of related non-volatile state), address it.

Context

Surfaced while reviewing the code-quality bot output on #816. Out of scope for the connection-pooling / try-with-resources work (#846, #855, #857) — filed as a standalone follow-up. Not a blocker for #816.

Start with src/main/java/dbProcs/MongoDatabase.java, especially the volatile baseMongoClient declaration and the synchronized initialization near line 189. Review the CodeQL finding from #816 against the Java Memory Model and check whether related reads or state are involved. Done means confirming the finding’s status and either dismissing it with an explanation or addressing the demonstrated ordering concern.