-
- /*
- * Return empty if the requested value is outside our valid range.
- */
- LWLockAcquire(CommitTsLock, LW_SHARED);
- oldestCommitTs = ShmemVariableCache->oldestCommitTs;
- newestCommitTs = ShmemVariableCache->newestCommitTs;
- /* neither is invalid, or both are */
- Assert(TransactionIdIsValid(oldestCommitTs) == TransactionIdIsValid(newestCommitTs));
- LWLockRelease(CommitTsLock);
-
- if (!TransactionIdIsValid(oldestCommitTs) ||
- TransactionIdPrecedes(xid, oldestCommitTs) ||
- TransactionIdPrecedes(newestCommitTs, xid))