diff options
Diffstat (limited to 'src/mongo/db/transaction_participant.h')
| -rw-r--r-- | src/mongo/db/transaction_participant.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/src/mongo/db/transaction_participant.h b/src/mongo/db/transaction_participant.h index e2047a44a79..281181904f3 100644 --- a/src/mongo/db/transaction_participant.h +++ b/src/mongo/db/transaction_participant.h @@ -58,6 +58,16 @@ class OperationContext; extern AtomicInt32 transactionLifetimeLimitSeconds; +/** + * Read timestamp to be used for a speculative transaction. For transactions with read + * concern level specified as 'snapshot', we will use 'kAllCommitted' which ensures a snapshot + * with no 'holes'; that is, it is a state of the system that could be reconstructed from + * the oplog. For transactions with read concern level specified as 'local' or 'majority', + * we will use 'kLastApplied' which gives us the most recent snapshot. This snapshot may + * reflect oplog 'holes' from writes earlier than the last applied write which have not yet + * completed. Using 'kLastApplied' ensures that transactions with mode 'local' are always able to + * read writes from earlier transactions with mode 'local' on the same connection. + */ enum class SpeculativeTransactionOpTime { kLastApplied, kAllCommitted, @@ -640,6 +650,14 @@ private: OperationContext* opCtx, SpeculativeTransactionOpTime opTimeChoice); + + // Like _setSpeculativeTransactionOpTime, but caller chooses timestamp of snapshot explicitly. + // It is up to the caller to ensure that Timestamp is greater than or equal to the all-committed + // optime before calling this method (e.g. by calling ReplCoordinator::waitForOpTimeForRead). + void _setSpeculativeTransactionReadTimestamp(WithLock, + OperationContext* opCtx, + Timestamp timestamp); + // Finishes committing the multi-document transaction after the storage-transaction has been // committed, the oplog entry has been inserted into the oplog, and the transactions table has // been updated. |