diff options
Diffstat (limited to 'src/backend/access/transam/commit_ts.c')
| -rw-r--r-- | src/backend/access/transam/commit_ts.c | 39 |
1 files changed, 27 insertions, 12 deletions
diff --git a/src/backend/access/transam/commit_ts.c b/src/backend/access/transam/commit_ts.c index 834010ff716..8f09dc83ae7 100644 --- a/src/backend/access/transam/commit_ts.c +++ b/src/backend/access/transam/commit_ts.c @@ -545,19 +545,11 @@ ZeroCommitTsPage(int pageno, bool writeXlog) /* * This must be called ONCE during postmaster or standalone-backend startup, * after StartupXLOG has initialized ShmemVariableCache->nextXid. - * - * Caller may choose to enable the feature even when it is turned off in the - * configuration. */ void -StartupCommitTs(bool enabled) +StartupCommitTs(void) { - /* - * If the module is not enabled, there's nothing to do here. The module - * could still be activated from elsewhere. - */ - if (enabled) - ActivateCommitTs(); + ActivateCommitTs(); } /* @@ -570,9 +562,17 @@ CompleteCommitTsInitialization(void) /* * If the feature is not enabled, turn it off for good. This also removes * any leftover data. + * + * Conversely, we activate the module if the feature is enabled. This is + * not necessary in a master system because we already did it earlier, but + * if we're in a standby server that got promoted which had the feature + * enabled and was following a master that had the feature disabled, this + * is where we turn it on locally. */ if (!track_commit_timestamp) DeactivateCommitTs(); + else + ActivateCommitTs(); } /* @@ -591,6 +591,9 @@ CommitTsParameterChange(bool newvalue, bool oldvalue) * * If the module is disabled in the master, disable it here too, unless * the module is enabled locally. + * + * Note this only runs in the recovery process, so an unlocked read is + * fine. */ if (newvalue) { @@ -620,8 +623,20 @@ CommitTsParameterChange(bool newvalue, bool oldvalue) static void ActivateCommitTs(void) { - TransactionId xid = ShmemVariableCache->nextXid; - int pageno = TransactionIdToCTsPage(xid); + TransactionId xid; + int pageno; + + /* If we've done this already, there's nothing to do */ + LWLockAcquire(CommitTsLock, LW_EXCLUSIVE); + if (commitTsShared->commitTsActive) + { + LWLockRelease(CommitTsLock); + return; + } + LWLockRelease(CommitTsLock); + + xid = ShmemVariableCache->nextXid; + pageno = TransactionIdToCTsPage(xid); /* * Re-Initialize our idea of the latest page number. |