diff options
Diffstat (limited to 'src/mongo/db/repl/split_prepare_session_manager.h')
| -rw-r--r-- | src/mongo/db/repl/split_prepare_session_manager.h | 39 |
1 files changed, 34 insertions, 5 deletions
diff --git a/src/mongo/db/repl/split_prepare_session_manager.h b/src/mongo/db/repl/split_prepare_session_manager.h index 6a53763e73b..7732ff8853e 100644 --- a/src/mongo/db/repl/split_prepare_session_manager.h +++ b/src/mongo/db/repl/split_prepare_session_manager.h @@ -39,6 +39,19 @@ namespace repl { using PooledSession = InternalSessionPool::Session; /** + * This struct contains information for a split session, including the split + * session itself and the id of the requester who wants to acquire the split + * session, which is usually a writer thread from the oplog applier. + */ +struct SplitSessionInfo { + PooledSession session; + uint32_t requesterId; + + SplitSessionInfo(PooledSession&& sess, uint32_t reqId) + : session(std::move(sess)), requesterId(reqId) {} +}; + +/** * This class manages the sessions for split prepared transactions. * * Prepared transactions are split and applied in parallel on secondaries, and this class is @@ -57,22 +70,35 @@ public: /** * Creates split sessions for the given top-level session and track the mapping. * + * The txnNumber is the txnNumber of the top-level session that needs to be split. It + * servers as a sanity check: onces a session is split, it can not be split again for + * another txnNumber until it releases the existing split sessions. + * + * The requesterIds is a sorted list of requesters (usually writer threads from the + * oplog applier), each of whom wants to acquire a split session. + * * Asserts if the given session is already split. */ - const std::vector<PooledSession>& splitSession(const LogicalSessionId& sessionId, - TxnNumber txnNumber, - uint32_t numSplits); + const std::vector<SplitSessionInfo>& splitSession(const LogicalSessionId& sessionId, + TxnNumber txnNumber, + const std::vector<uint32_t>& requesterIds); /** * Returns a vector of split sessions for the given top-level session, or nothing if * the given session has not been split. + * + * The txnNumber servers a sanity check to make sure it is the same as the one being + * used for splitSession(). */ - boost::optional<const std::vector<PooledSession>&> getSplitSessions( + boost::optional<const std::vector<SplitSessionInfo>&> getSplitSessions( const LogicalSessionId& sessionId, TxnNumber txnNumber) const; /** * Returns true if the given session has been split, or false otherwise. This can be * used as an alternative to getSplitSessionIds() when the result is not needed. + * + * The txnNumber servers a sanity check to make sure it is the same as the one being + * used for splitSession(). */ bool isSessionSplit(const LogicalSessionId& sessionId, TxnNumber txnNumber) const; @@ -80,6 +106,9 @@ public: * Releases all the split sessions of the give top-level session into the session pool * and stops tracking their mapping. * + * The txnNumber servers a sanity check to make sure it is the same as the one being + * used for splitSession(). + * * Asserts if the given session is not split. */ void releaseSplitSessions(const LogicalSessionId& sessionId, TxnNumber txnNumber); @@ -92,7 +121,7 @@ private: InternalSessionPool* _sessionPool; // A map to track top-level sessions and their splits. - LogicalSessionIdMap<std::pair<TxnNumber, std::vector<PooledSession>>> _splitSessionMap; + LogicalSessionIdMap<std::pair<TxnNumber, std::vector<SplitSessionInfo>>> _splitSessionMap; }; } // namespace repl |